Archive for October, 2009

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