Archive for 2009

First knee reglassed (Part 2)

See knees part 1.

Jon cut two triangles of 3/4″ plywood that I sandwiched together and used as an extension to the bottom of the knee–this was an excellent piece of advice I received from Paul Rosenthal (justifying the cost of having him out for a consultation by itself).  He also convinced me (or pointed out) that there was no good reason for putting a reinforcing pad of fiberglass between the knee and the deck.  As he explained, the deck should only take the load if the construction is wrong–the hull should be taking all the load.

This was my lay-up (so that I remember two days from now when I do the next one):

large fillet of epoxy thickened with chopped glass (a container of ready-made chopped glass from TAP plastics).
Strip of 6oz glass ~1cm
strip of knytex ~2cm
6oz glass ~3cm
knytex ~3in
6oz glass ~5in
knytex ~6in
knytex ~7in
knytex ~8in (4in each side)
6oz glass ~9in

The knytex is a layer of mat and biaxial fabric bonded together; it is thick and extremely strong.  It does not like to take corners at all–hence the thick fillet.  If not for the thick fillet, the knytex would pull away from the joint and leave a gap (and weakness).

I think the job is strong enough.  I am not a fiberglass professional and so I worry about various things, like whether I use too much resin, and other small things, but until someone smarter tells me what to change I have to plow forward with what I’ve got.

Knees Broken (Part 1)

My worst fears have come true: the raised lumps on the deck that we discovered while refinishing are caused by the knees, which have separated from the hull and are rotating up and pushing on the deck inboard of the chainplates.  Three out of four knees have ~1/8″ to 1/4″ gaps at their bottom ends, and the tabbing towards the bottom is colored white, further indicating delamination from the hull.

We were intending to depart in January; I don’t see how that’s possible now with this job thrown into my lap at the last minute.  Karen and I just moved onto the boat, and I’m going to have to rip out the cabinets and do a massive fiberglass grinding and repair.

I removed the slats that hide the port forward lower; I chose to tackle this one first because it doesn’t require removing cabinets to access it.

I used plastic to tape off the entire area.  I wore a bunny suit, full facemask, and respirator.  I ground the fiberglass tabbing off until reaching clean, solid glass.  That part really sucks, the grinding.

 

Refinished Deck

Ooh boy this has been a long time coming.  I have been looking forward to this job more than any other, for the past year, because it is one of the few jobs that people walking down the dock can actually see and admire.  Most everything else I do on the boat is hidden behind some panel and goes unseen and unsung.

Since we bought the boat, the deck has become increasingly ugly.  We made no attempts to keep errant epoxy or other crap from marring the surface; many spots have holes drilled for the purpose of repairing minor delamination; some areas jonny gooped over with plain epoxy in a failed attempt to fair the surface where there was some crack or hole.  The final state of the deck before I started sanding it was undeniably shameful.  Some might argue that appearances don’t matter and that our deck only looked ugly, but the truth is that there were cracks and holes all over the place that were admitting water into the balsa core and causing increasingly serious delamination (see my post regarding the delamination mess).

Since other projects have been so much higher priority, I have had a really long time to dream up how I was going to tackle this project.  I went through a number of different options for which non-skid to use.  For a few months I was planning on going the way of Wally, using a product called Ultra-Tuff.  Fortunately, Wally’s boat Stella Blue happened to be in a marina less than 10 minutes away at the time, so I got in touch with him and went over to see for myself how it turned out.  I have the utmost respect for Wally–he does the most meticulous and ridiculously successful work on his boat of anyone I know and his project pages have been invaluable to me–but I didn’t like the ultra-tuff that much.  Largely because it was a sharp, fairly brittle feeling surface, and not too pretty.  I definitely didn’t want to do the shake-sand-on-paint route, or the route of putting “microballoons” or some other such artificial sand in the paint and rolling it on, etc, because all of those decks that I have seen look very amateur, very DIY, and didn’t seem all that non-skid either.

All of those methods are still a hundred times better than our deck was before I touched it, and all perfectly adequate solutions.  But I had about a year to plan this project to perfection, and since the sheer magnitude of this job is overwhelming, I needed to feel like I would be really excited and proud of the end result, or else my motivation would waver.

I ended up choosing a product called Kiwi-Grip, because of the ease of application, the ease of recoating when necessary, and the look of the finished surface (as viewed up-close on various web pages where I found references).  It costs $100/gallon and you have to use a lot of it to get a really nice texture.  I ended up using 2.25 gallons to do the entire boat.

I elected to brush on a two-part polyurethane paint for all the non-non-skid (i.e. “skid”) areas.  Usually this means the trim around the edges of hatches, the outside edge under the caprail, etc.  Two-part polyurethane is synonymous with “linear polyurethane”, which I can abbreviate as LP, and that’s a hell of a lot easier to type from now on.

LP is harder to apply nicely than single-part polyurethane.  The surface of it gels quickly, so you have to start painting and keep moving and you can’t go back and fix “mistakes”.  For the professionals, “mistakes” refers to brush strokes that remain visible in the paint after it cures, instead of disappearing into a mirror-finish gloss that looks like it was sprayed on.  For me, “mistakes” refers to long drips and runs and uneven gobs of paint, etc, in spots where I accidentally caught the brush on an edge, or couldn’t see the white-on-white paint dripping down, etc, and so my mistakes are very obvious.  The good thing is that the mistakes don’t matter for the functionality.  LP is a hell of a lot more durable and long-lasting than single-part polyurethane, so I get to claim victory for choosing the LP even if it does end up looking like shit.

I chose Interlux Perfection for my two-part polyurethane, because we can get a deal on it, it’s made for amateurs like me, and it is popular (i.e. reliable).  In retrospect, I may have chosen a cheaper alternative.  Even with our deal, the stuff is way overpriced.

So the order of things is as follows:
pick a section of the deck, then . . .
1) sand deck with 80grit
2) prepare spots that need fairing by digging out loose shards of gelcoat
3) vacuum up dust
4) wipe down spots that need fairing with acetone
5) mix up a batch of Quikfair and apply to all prepared digs, holes, scratches, etc
6) sand down quikfaired areas with 80 grit
7) if inadequately faired with only one round, repeat steps 3-6
8) vacuum all dust
9) mask off
10) wipe down/clean the deck with the thinner (in this case Interlux 2333N)
11) paint coat 1 of two-part epoxy primer (I used Interlux Primekote)
12) lightly sand with 120grit
13) vacuum all dust
14) wipe down with 2333N
15) paint coat 2 of two-part epoxy primer
16) lightly sand with 120 grit
17) vacuum all dust
18) re-mask off for only LP areas
19) wipe down with 2333N
20) paint coat 1 of LP (I used Interlux Perfection)
21) lightly sand with 320 grit
22) vacuum all dust
23) wipe down with 2333N
24) paint coat 2 of LP
25) re-mask for only non-skid areas
26) wipe down with acetone
27) paint kiwi-grip (one coat only (hopefully!))
27) pull up tape and admire
28) repeat steps 1-27 for other sections of the deck

One thing I’ve learned from this whole affair is that all of the two-part stuff is way more of a pain in the ass than all of the one-part stuff.  To start with, you can just open a can of the one-part stuff, mix it up, and start going.  And then close up the can at the end of the day.  With the two-part products, you need to open both cans, use little mixing cups or spoons or something to very accurately measure out perfect amounts of each, then use up the whole mixture usually within an hour or so (there’s always a time limit on the two-part stuff), and whatever extra you have is wasted, but usually you’ll end up being about a quarter cup short, but you sure as hell don’t want to mix up another cup full of the stuff because it costs almost as much as gold.  Not to mention all of the two-part products are about 10 times more toxic and deadly than the one-part products–this includes the two-part epoxy bilge paint from sherwin-williams that gave me a headache for a day (I was stupid it was my fault, no respirator that time), the two-part epoxy bottom paint primer we used before painting the hull, the two-part epoxy primer paint (Primekote) I use on the deck, the two-part polyurethane Interlux Perfection, and even the regular old West System two-part epoxy (redundant since all epoxy is two-part).  Contrast this with the kiwi-grip, which is an acrylic water-based paint: I open the can, slap it on the deck with a brush, roll it out with the roller they provide, then put the lid back on and rinse everything out quickly and easily with water.

True, the LP will last a long time.  But on the other hand, wherever the non-skid starts to wear off, I can just grab the can and goop some more on in a matter of minutes (if I’m not too lazy to just ignore it for years that is).  Both approaches have their appeal.  After throwing away hundreds of small paper cups and whatnot in the course of mixing up these two-part poisons, I have to admit the Kiwi-Grip’s ease of application was pretty refreshing (though I’ll be singing a different tune if it only lasts a few months before it starts to fall off).

The pictures in the galley are in chronological order of how the boat was painted.  I did not sand the whole boat, then mask the whole boat, etc.  I did it in pieces.  First I did the rims and lids of the propane locker and lazarette with the primer and LP, then I did the foredeck with primer, then masked for the LP, then remasked for the non-skid on the foredeck.  Then I ran out of kiwi-grip on the foredeck and ordered more.

I learned, from doing the foredeck to completion first as a proof-of-concept, that you don’t want to put kiwi-grip down over the LP (I had inexactly masked before painting the LP, assuming that the edge of the LP didn’t matter once I put kiwi-grip over it).  I knew better but forgot.  Two reasons not to let the kiwi-grip end up over top of any LP: 1) it won’t stick well to the LP 2) the LP will show through the kiwi-grip much more, being glossy bright white and whatnot.  So after that I masked perfectly for the LP, then masked perfectly right next to it for the kiwi-grip.

After the foredeck, I did the port side deck and cockpit, more or less together.  I did it in pieces because it was just too overwhelming to try to do each stage over the entire boat all at once (actually, I did it in pieces because Karen convinced me to, and then I saw the wisdom of her reasoning).

Refinished wood on deck (scrape, sand, varnish)

. . . including dorade boxes, the hatch surrounds, cockpit coaming, and the caprail.  Jonny did this job.  I wish I had more pictures of the finished result, somehow forgot about that one.

Jonny did 4 coats on each surface.  First coat was thinned 50% to penetrate, second coat was thinned 25%, all coats after that were un-thinned.  Varnish used was the Epifanes high-gloss.

Added solar panels to the arch

We bought some solar panels from a guy in Berkeley, via craigslist: two 180W Mitsubishi panels for $360 apiece a total of 360W, for $720.  Exactly $2/W, which is a good price as far as I’m concerned.  Even better, they precisely fit the dimensions that I was seeking to fit in the space allotted for them on the radar arch.

Also, I included some additional photos detailing the arch mounting and construction.

Installed KISS wind generator

I bid $600 for a three year old KISS wind generator on ebay, never thinking I would win it (the minimum bid was $600), but I did.  I was the only bidder; I believe it was because the seller didn’t want to ship it and was located in Pennsylvania (really nice guy though–Mike if you read this don’t worry I’m treating the wind generator to the usage it deserves!).  Conveniently, I happened to be driving back east to get married at the right time, so we just stopped off and picked it up.  Also conveniently, jonny ended up buying a car right before attending the wedding, so he was able to put it in his car to drive it back to the west coast.

A few notes about the KISS: it is an AC alternator, so the power coming down the three lines out of the generator is three-phase AC.  The electrical box that is supplied with it is an on/off switch along with a rectifier.  Since the AC is more efficient than the DC, all other things being equal it is better to mount the electrical box closer to the batteries; i.e. use a longer run of cord for the AC and a shorter run after it is rectified to DC.

When the switch is turned to the on position, the generator is under load producing amperage that is fed to the batteries (duh); when the generator is switched to the off position, the generator is shorted out such that it self-brakes.  This self-braking works only up to a certain wind-speed.

There are thermal cutouts located in the alternator that will open-circuit the generator if it becomes to hot.  When the generator is open-circuited, the alternator can free-wheel and the blades can pick up speed.  As soon as the unit cools down enough, it restarts and puts the blades under load again.

So, there are three possibilities: the unit can either be under load and feeding power to the batteries, shorted and braking itself as best as possible, or open-circuited and freewheeling.

If the unit is free-wheeling faster than you are comfortable with (storm conditions), then you have to take a boat hook and use it to push on the tail to rotate the unit out of the wind.

Other models of wind generator have more sophisticated safeguards in them to deal with excessive wind, and even built-in charge controllers to protect the battery from excessive current–I share the opinion of the KISS generator’s inventor, however, that those safeguards are not worth the additional cost and complexity.  If you understand how the generator works and how to deal with it in the infrequent situations that it is either producing too much power or speeding out of control, then I see no need to spend the extra money on extra stuff to break.

I would recommend the use of Tef-gel on all the stainless to aluminum surfaces, i.e. the stainless bolts in the aluminum rotor hub, and the aluminum hub on the stainless rotor shaft–it seems to be by far the most lasting protection.

Fabricated new arch for radar, solar, wind generator

The old radar arch on the stern was a lot of metal tubing accomplishing very little–a mount for the radar and two dinky solar panels.  We were going to need something more to mount our wind generator and larger solar panels anyway, so I got it in my head to build my own thing for the stern.  I envisioned two vertical poles, the wind generator on one and the radar on another, with a rectangular frame in between for the solar panels.

First I was going to use aluminum, but I balked after my first attempt to weld aluminum ended with a weak joint in which I had no faith.  Then I was going to use cheap-ass galvanized pipe that you can get in any home depot.  But you have to be careful welding galvanized stuff–it’s poisonous when you burn it off–and it is only marginally corrosion resistant for a piece of metal that will be permanently mounted less than two feet from the salt water.  Then jonny convinced me to use stainless steel.  Initially I balked at that, because I knew that it would be ridiculously tedious to polish it up, and it needs to be polished up in order to be corrosion resistant.  But jonny convinced me by promising that he would do the polishing, and confidently proclaimed that it wouldn’t be that hard or take that long.

Many months later, it is complete and polished and mounted.  For the past month the two poles have sat on the deck of the boat, waiting for me to finish the polishing job that jonny only half completed.  Can’t say that I was really surprised; half-assed is jonny’s m.o. for all things boat related, and overconfident proclamations come out of his mouth only slightly more often than I have been convinced to believe them–which is a failing that I am trying to rid myself of once and for all.

Polishing the stainless was, as I predicted, a complete bitch.  We discovered via trial and error that the most efficient way to go from a flat matte grey finish to a mirror polish is to start with 220 grit sticky-backed sandpaper disks on the 7″ disc sanding pad on our milwaukee variable speed grinder (turned almost all the way down).  After sanding off all the matte grey, we used the stiffest buffing wheel we could find (the one with the most circles of stitching holding it together) combined with the coarsest rubbing compound–the type intended for “cutting or polishing of stainless steel”.  It takes absolutely FOREVER to get it to a decent polish.  In retrospect, I wish we had shopped around to hire the job out to some place.  Jonny did the majority of the work on them, then we mounted them temporarily to get measurements.  “Temporarily” turned into three weeks, and by that time there was already a patina of rust all over the areas of the pole that were not completely shiny.  It’s crevice corrosion, the bane of stainless steel; it happens wherever there is a scratch or a pit in the metal.  Keep it mirror shiny and it won’t develop a spot, but the rust will find the little scratches and make a home.

I used 2″ nominal 304 stainless steel pipe, schedule 10 for the vertical uprights, obtained for a reasonable price (which I have blocked out of my memory because reasonable for stainless is still way too goddamned expensive) from Alco in San Leandro I think.  Pipe and tubing are measured differently.  2″ tubing has an outside diameter of exactly 2″.  2″ nominal pipe, schedule 10 (refers to a thickness of .109″), has an outside diameter of 2.375″ and an I.D. of 2.157″.  I used 1.25″ dia. nom. pipe for the support legs and the crossbar, and the top pipe inserts on which the radar and wind generator are mounted are 1.5″ nom. pipe.  All schedule 10, since that’s the thinnest I could get and isn’t as thin as I wish it would have been.  I made myself a little chart to keep track of all the diameters, because no one could ever identify their pipe for me so I had to carry around a set of calipers and measure them for myself:

NominalPipeChart007

I decided on a vertical post on each side, each supported by two struts.  I didn’t want the struts to rise above the height of the pulpit–a style consideration, I just didn’t want all that metal blocking the view or experience aft of the boat.  That, and I knew it wasn’t necessary for strength (especially considering how crazy strong the pipes are that we’re using).

Jonny and I spent a whole morning fucking around with cardboard tubes and protractors trying to determine the exact angle that the struts needed to make (in both the horizontal and vertical planes around the vertical poles).  We used the average of all our measurements, and then I used the diameters of the two pipes and the angle between them to print out a “coping” diagram to use for cutting off the pipes, from this sweet website.  You print out the curve on a piece of paper, cut it out, wrap it around the pipe, then use a sharpie to draw the line on the pipe.  Then take the cutoff blade (or 5 of them) and a grinder, and painstakingly cut the pipe to match that curve.  Afterwards, the strut will rest against the vertical pipe just right.  Remarkably, it actually worked, and really well at that.

Then I welded the struts to the vertical poles at the tech shop.  Essentially I learned to TIG weld just for this project, so I don’t have very much experience.  And it shows.  The weld job I did is acceptably strong, I hope, but it isn’t pretty and it is far from admirable to those who know welds.  In a nutshell, I went over it too many times, trying to make it look nice, and in the process heated the metal too much, causing the weld to be weaker and more prone to corrosion than it otherwise would be.  I’m not too hard on myself for it, because it’s still pretty good considering how little experience I have.

I’m glad I was so anal about measuring the angles accurately, because the poles just barely fit in place.  In truth, on one side we needed to fabricate a shim to go between the strut and the hull because I didn’t get it quite right.  It was a tall order to get it even as close as we did, so I’m just thankful that it works.

I fabricated the brackets to mount it to the hull out of a scrap piece of stainless box iron: I cut the box in half and then in half again to get L-brackets.  Again, polishing these up was ridiculously tedious.

I cut backing plates for the brackets out of a scrap piece of thick-ass stainless–1/4″ thick I think.  Two of the plates sat on a curved piece of the hull, and I was concerned that when we cranked down on it it could break the fiberglass, so Jonny puttied up the backside (the surface that the plates would sit on) with thickened epoxy and then smooshed the plates down onto it (with a piece of waxed paper between) to form a nice base for the plates to sit on.

So I welded the supports to the vertical pole, but I decided that I wanted to use fittings to mount the rest of the supports in place–I wanted them to be adjustable and removable if necessary.  I went with “speedrail” fittings for the pipe, then had TAP plastics fabricated some starboard bushings to mate our leftover 1″ stainless tube into the pipe fittings (I couldn’t find any commercially available adaptors, anywhere).  Our old bimini frame (1″ stainless tube) had been hanging off the bow for months; I cut almost all the pieces I needed for the solar panel frame out of the old bimini apparatus.

At the top of each of the vertical poles I made a 1.25″ nom diameter pipe insert, that bolts inside.  I welded the radar mount to this insert (instead of directly to the top of the vertical pole) so that it can be removed with two bolts.  The wind generator got mounted to the insert on top of the other pole (the KISS wind generator is designed to be mounted onto either 1.5″nom pipe or 2″ tubing).

The resulting framework is the strongest of any I’ve seen.  It is probably also the heaviest, but my intuition tells me that our mounting points on the hull are going to be strong enough to handle it all (I really hope we don’t have problems with it!).

Replaced Heat Exchanger; FIXED ENGINE OVERHEATING

Finally!  After replacing nearly everything else in the cooling circuit, I decided the problem must be the heat exchanger, even though we already cleaned it out with muriatic acid.  I bought a new one from Transatlantic Diesel (they know their stuff over there) although I asked for a heat exchanger for a Perkins 4-108 instead of a Westerbeke and so they sent me the right one for the wrong engine (our Westerbeke engine uses a Perkins 4-108 block and so for most purposes it’s really a perkins 4-108).  I called them and they sent me the right one no problem.

It took only a few hours to put it in.  Afterwards I ran the engine at an idle at the dock, then put it in gear and let it strain against the docklines a bit.  It never got above 185, whereas before it would overheat while sitting at the dock in idle.

The new heat exchanger is a better design than the old one, as well: the new one has a bolt with metal end caps and a gasket underneath, so that it can be fully dismantled.  The old one had a single rubber endcap, allowing access only to the center of the tubes (one half of the circuit).

Granted, we won’t know for SURE until we take her out and run it hard, but I’m optimistic that we finally fixed the problem.

HeatExchangerNew1

Replaced seawater faucet (again)

When we took out the pressurized freshwater system, we removed the standard kitchen-style faucet that was in the galley and replaced it with a home-made faucet fashioned out of a piece of copper tubing, to use for the seawater foot pump we installed.  We spent a lot of time with various fittings and heat shrink tubing to make our own fixture that would be able to rotate yet not leak.  It worked for a few months, then one day I grabbed it and tried to rotate it out over the sink and the copper tubing just twisted on me.  Clearly it wasn’t going to be a lasting solution.  So I bit the bullet and bought a brass fixture from Svendsens.  Then of course I had to drill a new hole to accomodate it, since the old hole was way too big and there weren’t enough threads on the fixture to let me fit large washers.

Installed Battery Monitor

After spending $1200 on new batteries, I want some simple way to monitor their state of charge, largely so that we have a better idea of when we need to run the engine to charge them back up.

It is best to recharge a lead-acid battery before the charge drops below 50% (of the amp-hour capacity); if you discharge them too much you damage them.  And it is not practical to charge them all the way to 100% with the alternator each time–as the batteries approach full charge the charging process gets slower and slower.  When you are idling the engine only to charge the batteries, you want to limit the amount of time it runs.  So it is more practical to charge the batteries only to about 85%.  This means that in actual practice you will only use 85%-50% =35% of your total battery capacity during each charge cycle.  Our total battery capacity is 720Ah, so I expect that we’ll be able to use 250Ah before needing to turn on the engine–and hopefully the solar and wind and tow generator will keep up so that we never have to.

If you let your batteries sit for 12 hours with no sources or sinks connected to them, then you can simply measure the voltage and know the state of charge (11.6V is 50% discharged; 12.7V is fully charged).  But while cruising we will never let our batteries rest without some device drawing power, so we cannot simply watch the voltage to know how charged they are.  Hence the battery monitor.

I chose the Xantrex LinkLite, because Xantrex makes great stuff and we got a great deal on it at Svendsens.  It required a fair bit of wiring, since it uses a shunt installed in the battery negative (big-ass cable) to measure the current.

I have been told by many people that the batteries need to be fully charged every once in a while (i.e. up to 100% not just 85%) in order to stay in sync.  I just put it in this past week so I can only comment on how pretty it looks in our electrical panel.

BatteryMonitor1

Our first weeping blister

Well I have been sanding the entire boat, piece by piece, to repaint.  Turns out the side of the cabintop has hundreds of small blisters, a very few of which started weeping after we sanded (or maybe before, but none of us noticed).

These are the first of the infamous Valiant blisters that I have experienced, so I consider myself lucky.  The bulging ones can be ignored, but I feel the need to take care of the ones that are weeping, so that the paint will stick when I put it on.  Not like it will help much–those other hundred blisters will probably be weeping within a few months anyway–but it is after all only cosmetic so I’m going to get my painting finished and then call it good, and do my best to ignore the rest of the blisters that will surely come.

I dig out the blister with a sanding tip on the dremel, until it looks like all the wet stuff is gone.  Then clean/dry with acetone on a rag.  Then mix up a small batch of quikfair and spread it on, trying to leave the surface of the quikfair a little high.  After it dries (sandable in about 5 hours) I sand it fair.  Then it’s ready for the normal painting procedure (two coats of epoxy primer, two coats of two-part polyurethane).

blister1

Can anyone identify this windlass?

And give me a link to a manual for it?  I have no idea how to take it apart and service it.

I know it needs servicing because every fifth crank or so I move the handle without anything happening.  It feels like the pawls don’t want to catch, or something.  Regardless, the windlass is important, and no doubt it looks like all hell inside, knowing my luck and having experienced everything else breaking on the boat.

Replaced engine water temperature gauge and sender

Not sure if the old gauge and sender were operational or not.  Even if it worked, I hated the old gauge because it had one uncentered tick mark between 180 and 240 degrees, so it was impossible to tell what the actual temperature was.  What good is that?  I only care about the temperature in that range anyway!

I was under the impression that the gauge and sender have to be matched to each other or else they won’t be accurate.  I still don’t know whether or not this is the case, though I have since discovered that there is a standard for the senders (separate for american and european) so that in theory any american sender should work with an american gauge.  Regardless, I didn’t want to take a chance so I just ordered them as a set from Sherri at Transatlantic Diesel.  When they showed up I was frustrated, because the gauge had the same shitty problem as the original one, and I was disgusted by the idea of replacing our old gauge with one that was equally useless.  So I bought another one, a digital one off the internet that came with its own sender.  Of course when it showed up I discovered that the sender is too small to fit in our 1/2″ npt spot for it on the engine, and even though I have an adaptor that accepted it, it still wouldn’t work because the sensing tip on the sender was too short to protrude through the adaptor plug.  Just figures.  So I borrowed Jim’s thermocouple (Jim’s on Kanga down the dock from us) and set up a jury-rigged little science experiment in the galley, consisting of a pot of water on the stove, with the thermocouple and the sender in it, wired up to the gauge, which was jury-rigged to the back of the electrical panel to give it some power, and then I sat there over the stove, holding the sender in the water in one hand and the thermocouple in the other while the pot of water heated up, and tried not to burn myself as the water got all the way up to boiling.  Crude, but the experiment convinced me that the gauge and sender are compatible.  The gauge appeared to be reading ~8 degrees low, or else only a few degrees low and just lagged behind the response of the thermocouple.  I should have waited to see what it read while the water dropped also (to resolve that question) but I was out of patience and in the middle of a shitty conversation with jonny.  So I am satisfied with that level of accuracy for now, and I’ll use the thermocouple in the holding tank of the engine eventually to check it again.

So I mounted and wired the temperature gauge into the panel.  Now of course I have to change around my master wiring diagram because it’s pretty different from what it used to be (I had to move around a number of the hot and gnd supplies for the other gauges, since they had been piggybacked onto the old temperature gauge).  But anyway I have faith in the temperature gauge and I’m ready to start the engine back up and see if we still have an overheating problem, or whether either the new cam in the seawater pump or else the new gauge have resolved the issue.

fyi Gordon May’s info on testing engine gauges is extremely well written and valuable advice.  I have uploaded the pdf “GaugeTesting” to my site, so that it still exists when the original post goes away.

Tried to repair delamination; made a mess

There was one remaining area of the cabintop just forward of the hatch over the galley that was  delaminated when we bought the boat, and never got around to fixing it.  My sense was that the delam was not due to water penetration, but rather just a spot where the deck came unglued from the core, and that’s why it wasn’t a top priority on my list.

Since we are currently refinishing the deck, it is time to take care of it now.  I took the hammer around and tapped in a few other spots and found more delamination (big surprise–go looking for a problem on a boat and you are bound to find it).  I took a pencil and the hammer and circled the area that was sounding hollow.  Then I selected a drill bit sized to the syringe that I have for injecting the epoxy, and I drilled a number of holes all over the place in the area.  Then Karen and I mixed up bowl after bowl of epoxy and injected it into the area.  Karen jumped down below to make sure it wasn’t finding a way into the boat, and saw nothing.

The next day I showed up at the boat to discover a cured puddle of resin covering the galley sole, and stalagtites of resin around the hatch above the puddle.  I spent an hour and a half grinding the resin off the floor with the belt sander (36 grit) and another hour and a half chiseling apart the ceiling trim and panels.  Now the floor of our galley has a large spot of ugly bare wood that I need to polyurethane, and I still haven’t successfully fixed the delamination on the deck.  That sucked.

Replaced cam in seawater pump

As mentioned a few posts ago, I pulled the seawater pump off the engine expecting to notice wear on the back plate.  I didn’t find that, but I did notice that the cam appeared worn.  For $50 I got us a new one and installed it.  Haven’t run the engine yet to know if this will help with the overheating.  You tell me, does it look like the old one was that bad?

Refrigeration, pt 5 (FINAL)

Pt 1
Pt 2
Pt 3
Pt 4

I installed gauges in the countertop above the icebox: a thermometer (convenient to have one outside the fridge so you don’t have to open the box to check), a green LED that lights up whenever the compressor is running, a red LED to show faults, and an hourmeter to use in measuring the duty cycle.

Here is the wiring diagram for my system:

IceboxWiring

Also, here is a pdf for the Danfoss BD50F_compressor.

I did not install the plumbing or the pump for the water-cooled condenser–I’m going to wait to buy that stuff until hotter climates (other projects take priority).  Up in the bay area the air-cooled condenser is more than adequate, and more efficient than running the water-cooled condenser anyway.

The whole box is painted with two coats of Primekote and two coats of Perfection.

The icebox has stayed 32-38 for the past three weeks, so it’s working well.  We have been having some issues with the compressor short-cycling (coming on for two minutes, going off for three, back on, etc).  The situation started to worry me when we started getting the intermittent fault code of three red blinks: indicating “rotor blocked or pressure differential too high”.  I speculate that the compressor was trying to turn on again too quickly–before the pressure differential had sufficient time to equalize through the evaporator plate.  My research on kollman’s forum and the rparts forum tells me that the short-cycling is a result of too much of the thermostat sensor touching the evaporator plate.  I have pulled all but an inch of the sensor tubing off of the plate, coiled up a few inches away from it.  It seems to be working better, but I haven’t got a trustworthy data set yet to be sure.  Aside from that, the box is totally finished:

Replaced batteries in house bank

Two of the old batteries wouldn’t hold a charge, and the other two were low capacity, unfortunately mostly due to neglect (not being kept topped off with water).

The old ones were 4 Rolls-Surrette EIGH 262, each of which is 6V and 262Ah (at the 20hr rate).

The new ones are 4 Rolls-Surrette S460 (pdf datasheet here), each of which is 6V and 350Ah (20 hr rate).  They are marketed to the solar energy crowd, which is why they quote the capacity at 460Ah at a 100hr rate, which just isn’t the way us sailboat people measure it.

The new batteries are exactly the same footprint as the old ones, but about 5 inches taller.  As a result, we had to remove the old battery box and modify it to allow for more headroom (there are things mounted over the batteries close enough to have prevented them from fitting).  I cut out the bottom of the box on the left side and dropped it down, cut side pieces, lightly screwed it together, then jonny glassed over it, then we painted it with a couple coats of Primekote epoxy paint.

Remaining: fabricate new acrylic cover to go over the top (to protect against tools, or the furnace cover, from shorting out on top of the batteries), and add buckles to the webbing straps.

Installed echo charger

The echo charger siphons charge from the house bank to the starting battery, up to 15A.  It follows the voltage of the charging source, and cuts the circuit whenever it is below ~13V (a one-way valve to keep the starting battery from draining, and charged up).

We have a Xantrex Freedom 20 inverter/charger that has a built-in echo charger.  After we installed the starting battery a year ago I wired this up to the starting battery.  However, at some point it stopped working, and it would cost more to pull out the large unit and ship it off to be fixed than to buy a new echo charge ($120).

I mounted the new stand-alone echo charge above the batteries in the engine room; so far it is working as it should.

IMG_2582

discovered lumps

While sanding the boat pre-painting, we discovered three lumps (one starboard, two on port) inboard of the shrouds, where the knees underneath are exerting upward pressure on the deck.  No word yet on whether this should be cause for alarm.  Here are some pictures; it’s hard to see.  The blue is where I sanded through the gelcoat on the lump.

repaired jib sheet foot blocks

The jib sheet runs aft to a turning block, turns 180, and leads to the winch.  The last sail we were close-hauled in decent wind and I noticed that the bracket on the port side was bending–starting to rotate forward under the force.  We pulled the brackets from the boat, I fabricated a couple of support struts from the spare sheet of 316 stainless we have, and then I welded them up down at the tech shop.  Jonny shined them up and we’ll put them back on after we paint the deck (hopefully in the next two weeks).

latest engine overheating frustrations

Possible Reasons for Reduced Capacity Engine Cooling, a list compiled from advice from members of the Valiant Owner’s Group:

1. prop fouled–try cleaning prop :: recently the diver checked our zincs and confirmed that our prop is not fouled
2. strainer outside boat clogged; remove hose from sea strainer and see how fast :: did that, sea comes in plenty fast the ocean comes into the boat (should be quite alarmingly fast)
3. sea strainer could be clogged beneath the basket even though it looks clear–take it off and run something through to check :: the test we performed for #2 should confirm that things are ok
4. the gasket on the cap of the sea strainer may not be air tight–we might be sucking in air as well as water
5. oil cooler could be partially plugged with impeller blades
6. even partial blockage in heat exchanger could cause the problem
7. cam in seawater pump may be worn out (difficult to tell by looking it it with amateur eye)
8. impeller might be sheered between hub and blades, even though it looks perfectly fine :: removed impeller to check–it’s ok
9. gauge might not be properly calibrated; get an infrared thermometer to check
10. fragments may be lodged in hoses or exit from raw water pump, or heat exchangers; remove hoses and sight down them to double check, try flushing with garden hose
11. clamps on raw water side might be loose; anything allowing air to be sucked in will mess up the cooling
12. back plate of raw water pump may be worn out–check to see if there is noticeable wear or grooves where the impeller has worn into the back plate :: checked–looks ok
13. cooling system may have an air-lock, especially with the hot water heater installation; try bleeding air from petcock on top of heat exchanger (is that high enough to take care of it?) :: removed our hot water heater setup and bled from the top of the heat exchanger (though the header tank is the highest point anyway)
14. thermostat could be the wrong temp, or not working properly  :: we replaced the thermostat (and checked both the new and old in a pot of boiling water beforehand)
15. heat exchanger, oil cooler, tranny oil cooler could be scaled up  :: we removed them and thoroughly cleaned them in a bath of muriatic acid)

The last time we went out (two weekends ago) the engine reached 180 on the gauge within 10 minutes, and was reading 230 around 20 minutes.  We were lightly motoring, barely above an idle.  Water was coming out of the engine exhaust (enough, I can’t tell).  I used the infrared thermometer on various spots of the engine.  The housing over the thermostat read ~190, the head next to the temperature sender read ~190, most all the spots on the head read ~190.  A spot next to the #1 fuel injector read 220.  I took this as a sign of overheating, though I’m not sure how to interpret the data.  The exhaust pipe (galvanized elbow) read 240.

I pulled off the seawater pump (again) to see if the back plate had any wear.  Doesn’t appear to.  Though it does look like the cam has some wear, and I found a salt deposit partially blocking one of the fittings.  So I ordered a new temp gauge, sender, cam for the seawater pump, and heat exchanger from Sherry at TA diesel.

Moved Propane Locker, Added Lazarette

The old propane locker was a fiberglass box mounted in the middle of the stern.  It protruded 5″ above the level of the seat, and was suspended in the enormous space of the lazarette, rendering the space unusable and the seat unseatable.

We decided to remove the old propane locker, build a new one tucked into the corner as much as possible, and put flush fitting hatches over the lazarette and propane locker.  The job ended up being the biggest so far undertaken on the boat, and isn’t yet finished.  Of the many unforeseen hurdles, we discovered that we needed to move and/or reroute all three of the scupper drains on the port side, to accomodate the new propane locker (not to mention close the old propane drain and install a new one).  So this job alone required 4 new through-hulls and two new scupper drains on deck.

Additionally, the deck just forward of the propane locker, especially around the rudder access hatch, was extensively delaminated (core was perceptibly soggy, damp, and black).  Jonny elected to dig out the core from the hatch and rudder post hole (i.e. without removing the top or bottom layer of fiberglass), and ended up removing the core to a distance of close to a foot in the space forward of the new lazarette hatch (there are some pictures of it).  Then he carefully measured and cut a few pieces of plywood that he buttered with epoxy and then shoved into the gap.  Afterwards there were some gaps left in the core where the plywood didn’t quite reach that I injected with resin, per the usual method (drill holes for the syringe, inject resin until it splooges out all over, let it cure, sand off the puddles of resin, quikfair the remaining divets, sand again).

We built the new propane locker and the hatches out of the leftover fiberglass-covered plywood that we had fabricated for the icebox. We used two layers of the plywood for each of the hatches (the plywood was super thin), as well as a couple extra layers of knytex for additional strength.

Jonny painstakingly glassed the box in place using strips of knytex–the box was odd shaped to accomodate the curves of the hull and the deck/coaming/toerail ceiling section.

We made the ledges on which the lids will rest out of 3/8″ thick prefab FRP from Mcmaster-carr.  The lip is about 1/2″ wide, and the strip that forms the lip extends ~1-1/2″ underneath the deck.  The strips are epoxied in place (jonny pre-drilled pilot holes and screwed the strips in place to properly position them while the epoxy cured).

Fairing and sanding the edges of everything was time consuming, as it always is.  It consisted of at least two rounds of Quikfairing, preceded by, separated by, and followed by tedious amounts of sanding.

I entirely replumbed the propane lines while we were at it.  Per jonny’s insistence we went with a hose to run from the stern to the stove, instead of copper tubing.  It was definitely the right choice.  It was slightly more expensive, but eliminated extra junctions required at the stove.  A hose is required at the stove to accommodate the gimballing, and this way the one 25′ hose runs straight to the back of the stove.  I purchased the new style qcc quick connector to be used for attaching to the propane tanks–the previous system required wrenches, and the apparatus that connected to the tank (which included the regulator and the pressure gauge) was awkward and unwieldy.  Now a single high pressure line is connected to the active tank, and the regulator, pressure gauge, and other connections are mounted to the propane locker wall.  I also added a T-junction and short additional hose with a valve inside the propane locker (in the low pressure side) to be used for a propane grill to be mounted on the rail (which we don’t yet own).

The resulting storage space gained in the stern is astounding.  I could lay down and take a nap in the space that we previously had no access to.

Turns out we left too much of a gap for the gasket, and the lids sink too low, so I created a wall of foil tape around the inside edge, and poured a mixture of slightly thickened epoxy into the gap.  After it cured I ground/sanded it down to the right depth for the gasket.

I figured out the hinge situation.  Then we painted the lids and the lips with two coats of the Primekote epoxy primer.  That’s as far as we’ve got so far.  Very close.

I’m not finished posting pictures yet, stay tuned for more.

Refrigeration, pt4

Pt 1
Pt 2
Pt 3

Built a platform and mounted the compressor, and built/faired the lid for the box.  Glued down formica laminate, then painted with two coats of Primekote, sanding in between.  Almost finished, just have to put on the two coats of Interlux Perfection, mount a ring pull in the lid, then seal down the hinges and run a bead of caulk around the countertop.

Refrigeration, pt 3

Pt 1
Pt 2

I built this:

And I pressure tested it using Marcus’s tank of argon and refrigeration gauges (thanks Marcus!), and I have NO LEAKS.  It was a very exciting moment for me, I’m not going to lie, I was really proud.

Next step: fabricate mounting platform for it, wire it up, then vacuum down the system and charge it up.

I’m working long days (paid work I mean) for a few months though, so I don’t have much time to work on boat stuff.

Installed Oil Transfer Pump

 

Changing the oil on the engine was unnacceptably difficult–you had to insert a small diameter tubing down into the dipstick tube (on the hard to reach side of the engine) and then pump it all out by hand.  Because the tubing had to be so thin to fit down the dipstick tube, it pumped super slow and hard, and was a tedious, laborious job. 

You don’t want it to be so hard to change the oil, or you won’t ever do it when you should.

My dad bought me an oil transfer pump for christmas, and we plumbed it into the drain plug fitting in the bottom of the oil pan.  It was challenging to piece together all the fittings in the tight space under the oil pan. 

The first time we used it confirmed all of our efforts–you pump out the old oil, then stick the end of the hose in the new oil and pump the new oil right back in the same way.  Simple, clean, quick, easy.

Added amidships cleat

In the previous setup, lines were tied to a shackle mounted on the deck and led through a fairlead on the toerail.  We wanted a proper cleat amidships, so we mounted one on each side directly on top of the toerail.  It has greatly improved our handling of the docklines.

refrigeration, pt 2 (building a compressor kit)

refrigeration pt 1

To recap: initially I was going to buy an Adler-Barbour Cold Machine, hook everything up, and be done with it.  After talking to Marcus, I decided to order all the parts from Rparts.com and build my own.

I ordered the 1M kit, which uses an air-cooled condenser and the Danfoss BD50 compressor, and comes with a small evaporator box.  Extra things I bought beyond what comes with the 1M kit: the small evaporator box is both too small capacity-wise and doesn’t fit well in our icebox, so I also purchased a large flat-plate evaporator, unbent, and we’re going to bend it ourselves (they wouldn’t switch out the small box for a large flat plate, but they gave me a 20% discount on the extra one, so I got it for $80).  I wanted to have both air- and water-cooled condensers, so I bought a water-cooled condenser which I am going to figure out how to mount and plumb in somewhere.  I bought a 40 amp relay to use for powering the water circulation pump, and an analog thermometer to mount outside the icebox.

The excellently written manual for the 1M kit is here.

It all arrived today.  It felt sort of like christmas, unpacking the boxes and discovering all of the parts.  I took photos of all the stuff spread out on the floor.  Below the black foam tubing are the extra parts beyond the 1M kit (and the white flat plate evaporator on the right).

There are a whole lot of parts for me to put together!  And I won’t be able to start on it for at least another two weeks.

more engine overheating problems

 

damn it we just can’t seem to catch a break when it comes to the engine overheating.  We went out for a fireworks show and on the way back we started overheating.  Fortunately, idling down to 3 knots boatspeed kept the temp under 200 so we were able to get home.  

Clearly, we have reduced cooling capacity.  A complete failure of the cooling system would be much easier to fix–it would be far easier to find the problem.  This reduced capacity could be cause by any number of things. 

I took some video of the water coming out of the exhaust, so I could hopefully get someone to tell me whether it looks satisfactory or not.  Of course, when we’re actually underway this probably changes (I know at times the dribble coming from the anti-siphon vent disappears). 

 

It could be something to do with our water heater plumbing.  I’ve heard terms like "airlock", and heard plenty of stuff about needing to bleed from the highest point, but I don’t understand what is up with our setup.  Here are some shots for people to look at:

The Valiant Owner’s Group had tons of great suggestions, which I compiled:

1. prop fouled–try cleaning prop
2. strainer outside boat clogged; remove hose from sea strainer and see how fast the ocean comes into the boat (should be quite alarmingly fast)
3. sea strainer could be clogged beneath the basket even though it looks clear–take it off and run something through to check
4. the gasket on the cap of the sea strainer may not be air tight–we might be sucking in air as well as water
5. oil cooler could be partially plugged
6. even partial blockage in heat exchanger could cause the problem
7. cam in seawater pump may be worn out (difficult to tell by looking it it with amateur eye)
8. impeller might be sheered between hub and blades, even though it looks perfectly fine
9. gauge might not be properly calibrated; get an infrared thermometer to check
10. fragments may be lodged in hoses or exit from raw water pump, or heat exchangers; remove hoses and sight down them to double check, try flushing with garden hose
11. clamps on raw water side might be loose; anything allowing air to be sucked in will mess up the cooling
12. back plate of raw water pump may be worn out–check to see if there is noticeable wear or grooves where the impeller has worn into the back plate
13. cooling system may have an air-lock, especially with the hot water heater installation; try bleeding air from petcock on top of heat exchanger (is that high enough to take care of it?)

things we already checked
-thermostat could be the wrong temp, or not working properly
-heat exchanger, oil cooler, tranny oil cooler could be scaled up

The next thing to do is run down this list I guess.  Really excited about that.

 

Installed new head and replaced all plumbing

I actually did this half a year ago, but I didn’t want to post without pictures of the head, and the whole room has been so dirty and full of crap that it took me a long time to finally get around to cleaning it up to take some pictures. 

I’m particularly proud of this job–I designed the whole system myself and I think it worked out really well.  Way back in mexico we tossed out the old head and all the associated plumbing, keeping only the holding tank installed in the v-berth.
 

I chose the Lavac for our new head.  The Lavac works differently from the standard marine heads.  Typically, heads use a somewhat complicated double action pump that is the weak point of the system.  The Lavac uses a regular Henderson Mark IV diaghragm pump.  To operate it, you close the lid and start pumping.  The lid seals to the toilet bowl, and as you pump out the shit, clean seawater is sucked in.  Then you can lift the lid and pump a few more strokes to completely empty the bowl.

I wanted damn good hose for this shitty task, so that hopefully it will take a really long time before it starts smelling bad.  I chose the Trident Sanitation hose #101.  It’s expensive but we got a great deal on it, and I really really don’t want shit smell to permeate our boat.

Designing a plumbing setup from scratch is not easy–you need to include hose and y-valves and pumps and fittings to fulfill the following actions: 1) Pump head to holding tank 2) Pump head to ocean 3) Pump holding tank to ocean 4) Let holding tank be sucked out from deck fitting. 

Check out the diagrams in the gallery below.  First I made the abstract schematic of how I wanted everything connected.  But the hardest part is getting all the components to fit in the available space, so then I made the schematic of how the system would fit into which spaces of our boat.  As it turned out, I deviated from the plan, and moved the location of two anti-siphon loops to a neighboring cabinet (to the left), and the pump went into the wall behind then head instead of the cabinet adjacent to it, but everything else fit where I thought it might.

The biggest hurdle was the last 10" section of hose going from y-valve to seacock.  The y-valve’s fitting, like everything else that touches poop, is 1-1/2".  But the through-hull was not.  I think the previous owners installed a "full-flow" 1-1/2" fitting, which has a 1-1/2" internal diameter, and 1-5/8" external hose barbs.   I spent hours over a period of a week trying to fit an 1-1/2" hose onto that seacock; I used soap to lube it, I used a hair dryer to soften it, then I used a heat gun to soften it, I even soaked the hose in boiling water.  Nothing was going to work, it was a futile attempt.  In the end, I used a larger hose and built up the 1-1/2" fitting on the y-valve to accomodate the larger hose (beware! if you try to just clamp a larger hose down onto a too-small fitting, it will leak!).  The svendsen’s people saved the day by pointing me to a product designed for plumbing repairs: a resin-impregnated fiberglass tape that is activated by air or water.  Just pull it out of the sealed package, wrap it tightly around the fitting to build it up as much as you want, wait an hour, then sand it down.  1-5/8" hose fit over it perfectly.

Another special feature of our head installation: I decided to add a second vent to the through-hull, opposite the existing one (old vent is to port, new vent is to starboard).  The thing with stinky odors is this: the stink is caused by the anaerobic bacteria.  If you keep the system aerated, you eliminate the bacteria that causes the smell.  Our old hose was 3/4" diameter and 12′ long from tank to through hull.  It doesn’t take a genius to realize that very little air is going to flow through that thing, without any cross-ventilation going on.  So I added some cross-ventilation in the for of a second vent.  I used 1-1/4" hose, which is particularly large as far as vents go, but it’s about a 12′ run from the holding tank to the vent through-hull so the air needs every assistance to flow.  Hopefully it will help keep our boat stink-free. 

The last thing I did (just did it this morning, actually) was make up a diagram of how the y-valves need to be oriented for different shit-paths.  That’s the last image in the gallery below.  When I mount it on the wall next to the toilet, it will correspond with the y-valves and handle positions on the backside of the cabinet, so it will be easy to know by feel where to put each handle (at least that’s the idea–time will tell whether it works).

Refrigeration, pt 1

We’re in the process of redoing the refrigeration.  Unlike other posts, in which the job is already completed and I give a very brief recap, I’m putting down my notes and choices while currently working on this project.

Our compressor was kicking on and off erratically for a period of probably 6 months after we started using the boat.  Each time it stopped working, jonny would lose a bunch of food that went bad in the icebox, and then he would have to clean it out when it started smelling, etc.  Finally we gave up and Jonny has been living without refrigeration for 6 months now. Also, I decided from my research that the insulation in our box was inadequate: 1) it’s 30 years old (it deteriorates big time in r-value) 2) there was 1.5″ on the top and 3″ on the rest of the box; there should be at least 4″.

At first we made minor attempts to figure out what was wrong with the old system.  I wasn’t going to participate in that attempt though, because I was convinced that we would need a whole new system regardless and I didn’t want to sink any time into messing with the old one.  If I was going to go at it full bore, I wanted us to do it right: first reinsulate the box, then replace the whole refrigeration setup.  Jon and Jonny were not psyched about this idea–justifiably so, because it represented a collosal amount of work and a couple thousand dollars–and weren’t ready to pull the trigger on a new system.  I didn’t try to persuade them, I just said that I would let them take care of repairing the old compressor, then.  🙂

In April I started tackling it.  I drew up detailed plans for the box and a list of steps, so that we could move as efficiently as possible once we started.  I decided on 4″ all around of Blueboard–an extruded polystyrene made by Dow–for our insulation.  Blueboard doesn’t have the highest R value of all the insulations available, but it is the most impervious to moisture and that means that after just a year or two it might be outperforming your other choices (lots of people use polyisocyanurate foam–commonly available at home depot, it looks like yellow foam with a foil backing–it absorbs moisture pretty readily!).  The only place within 50 miles that sells the blueboard is Pacific Supply in South San Francisco, and the Dow representative I talked to told me that their west coast machine only makes boards 2′ wide. The design of the lid is the hardest part.  You want it to ideally have the following features: double gaskets (top lip and bottom lip), flush mounted in the counter, minimal gap all around, angled front surface so it will open without jamming, easy to clean pretty finished surface.  Since you build the box from the bottom up, it can be tricky to get the interior of the box and the countertop to be perfectly spaced for the exact thickness lid, etc.  There are many ways of building it–the easiest is to buy a premade one for ~$500, from Glacier Bay for example.

Initially I knew nothing about how the refrigeration system worked, and I decided to buy an Adler-Barbour Cold Machine and evaporator plate, which come precharged with refrigerant and ready to go, and just hook them up and be done with it.  The total cost would be about $1300, and it could be installed in a day.  I was all ready to buy it when I ran into Marcus on the dock and stopped by to check out his new system.  Marcus was also in the process of rebuilding his whole refrigeration setup, including reinsulating (with vacuum panels!) two iceboxes, and building two compressor setups from parts himself.  He purchased all the specialized refrigeration tools necessary to do the work himself, including a vacuum pump.  Talking to him I was daunted by the amount of work and complication it represented, and in my mind I was still saying to myself “hell with that! I’m buying the adler-barbour!”  But Marcus suggested that I take a look at a website called rparts to at least see if there was a cheaper option for me.

I checked out rparts, looked at their do-it-yourself kits, looked at the list of parts contained in the kits, looked at the price ($800), and decided that maybe I would learn how to do refrigeration after all. So I downloaded the installation manual for the 1M kit they sell, and using the manual and the rparts website and Kollman’s forum I sat down with Calder’s refrigeration book (which I had already read twice, without much illumination) and figured it all out finally.  With the right combination of resources, each section of Calder’s book was now like a lightbulb going on.  It was gratifying to finally understand an area which had previously seemed so baffling to me. I am extremely indebted to Marcus for inadvertantly convincing me to learn it and do it myself.  “Do it ourselves” is our modus operandi for everything else on the boat, and it was out of character for me to want to simply pay money for a setup and not have to think about it or understand it or put in ridiculous amounts of time and labor for its installation.

I started by dorking out with Calder’s refrigeration book, and measured our box to calculate the surface area and thereby estimate the heat loss, in order to size the refrigeration capacity appropriately.  Here is my diagram:

IceboxAreaCalculation

You can think of the refrigeration system as a closed circuit of refrigerant with two heat exchangers: the heat exchanger in the icebox is the “evaporator”; the heat exchanger mounted with the compressor is the “condenser”.  The compressor itself is a just a refrigerant pump; it is the block ovoid shape easy to recognize in most pictures.

There are two common types of evaporators: the “evaporator plate” and the “holding plate”.  The evaporator plate is the simplest, cheapest, most maintenance free of evaporators.  It is a roll bond aluminum plate–“roll bond” describes the manufacturing process–that contains a network of channels through which the refrigerant passes.  Inside the icebox, the refrigerant passes through the plate and makes it cold, and then the plate cools the air around it in the box (which is why the plate must have space on all sides of it, so that all of the surface is working to cool the box rather than just one side).  The holding plate is actually an evaporator immersed in a specialized fluid (a “eutectic” fluid).  The refrigerant passing through the evaporator freezes the eutectic fluid, and then over a number of hours the eutectic fluid keeps the box cold.  Essentially the holding plate is a big reservoir for holding the cold, just like a big block of ice.  With a roll-bond evaporator plate, the compressor comes on and off more frequently, for shorter periods of time.  With a holding plate, the compressor comes on much less frequently (perhaps as little as once a day) but runs for a long time to completely freeze the eutectic fluid.  Which is better?  Entirely depends on your system, and there is continued debate.

There are two common types of condensers: air-cooled and water-cooled.  The air-cooled condenser is a series of fins (not unlike a car radiator) through which a length of the refrigerant tubing runs, and usually there is a fan to blow air over the apparatus.  The hot refrigerant passes through this and hopefully cools off in the process.  Obviously this is more likely to happen if the air temperature where the condenser is located isn’t 120 degrees (if it is you’re totally screwed).  The water-cooled condenser is more like the heat exchanger on the diesel engine: it circulates seawater to cool a length of refrigerant tubing.  There are a couple different models, “tube in a tube” and “shell type”, take a look at the offerings on the Rparts website.  There are a few more exotic water-cooled solutions out there; the “keel cooler” is a design that takes the refrigerant to the ocean instead of bringing the seawater to the refrigerant.  My favorite is the tube in a tube type (maybe because Calder seems partial to those).  The refrigerant goes through the center tube, and an electric motor pulls water from the ocean and pumps it through the outer tube and then back out of the boat. Air-cooled condensers are simple and require power to run a fan (~.2A).  Water-cooled condensers are more complicated because they require plumbing seawater from a through-hull and back out, and require power to run a pump (~1.5A).  The water-cooled condensers are much more effective at efficiently removing heat from the refrigerant, but until the air temperature gets really hot, the additional power required to run the water pump outweigh the efficiency gains in heat transfer.  The cutoff point of efficiency is debated (and different for every installation).  Calder thinks that water-cooled is essential for a functioning system in the tropics, Kollman is completely against water-cooled because of the increased complexity, expense, and failure rate.

A refrigeration system is a heat pump–it moves heat from the evaporator to the condensers, sucking heat out of the icebox and dumping it off at the condenser.  If you just pumped a liquid around in circles, from the evaporator to the condenser to the evaporator to the condenser, etc, then you would indeed remove some heat from the icebox and dump it at the condenser.  However, you can’t suck up much heat just by warming up a liquid and then cooling it off.  The real way to suck up heat and drop it off elsewhere is to use a phase change to your advantage. Consider a quart of water on the stove.  It takes 320 BTU of energy to heat that water from 33 degrees F to 211 degrees.  Then, to heat that water from 211 degrees to 213 degrees, it takes 1934 BTU.  At 212, the H2O changes from water to steam, and during that entire process you keep dumping in large quantities of energy and the temperature stays the same–all the energy goes into the conversion from liquid to gas.  The energy required to do a phase change from water to steam is way greater than the energy required to change the temperature. So we use that phase change to make refrigeration possible.  We don’t use water though, because we want the phase change to take place around the 20 degrees F in our refrigerator (not very helpful to us for it to take place at 212 degrees).  We pump a liquid to the evaporator, and then let it expand into a gas; that expansion to a gas sucks huge amounts of heat out of the box.  Then back at the compressor we compress the gas, which heats it up (essentially exchanging “pressure energy” for heat).  Then we send it through the condenser, where the the hot gas turns back into a liquid and dumps off all its heat in the process.  Then we sent the liquid back to the evaporator, where it turns into a gas again . . .

Once I decided that I was going to buy the kit and parts from Rparts and build my own system, I was free to design a system that includes both condensers:  air-cooled for cooler climates and water-cooled for when it gets really hot.  To alleviate Kollman’s concerns about the water-cooling, which I take seriously, I am going to take precautions against galvanic corrosion of the water-cooled condenser by electrically isolating it, and I’m going to wire in a PWM circuit so that I can turn down the power consumption of the water pump.

Jonny and I ripped out the old box in one day–the entire thing.  The next day I picked up 18 sheets of 2’x4′ Blueboard 2″ thick from Pacific Supply.  We lined the inside with a layer of aluminum foil, used spray adhesive to stick it in place.  I taped the seams with metal tape.  Then we made a huge mess cutting up the foam with the Dozuki saw–pretty easy and quick actually–and pieced most of the insulation in place. We bought two thin sheets of plywood and glassed over them with a few layers of fiberglass, then faired them smooth with quikfair, cut them to fit, and built a box inside the insulation.  Jonny glued all the edges together with fillets of thickened epoxy, then we sanded them fair, and painted the inside of the box with two layers of Primekote, an epoxy primer.

That’s as far as we’ve got.  I ordered the refrigeration parts from Rparts, and we need to wait to put the evaporator into the box before we put the lid on it and build the hatch for it.  So we’re probably 30% done with the job.

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