March 28, 2011

With the seemingly endless series of storms that have been coming through, I'm glad I have a boat! Although something more like an ark might be needed if this keeps up. When not fretting over the 30-50 mph winds and the rising creek behind my house, during the week I cleaned up the Skipper head parts, stripped the old paint off as needed and sprayed on a new coat of white epoxy. Although the old paint wasn't really in bad shape, it had obviously been slathered on thick and without any prep. The result was a coating full of runs, lumps and zits. Can't have that on my precious bronze throne! Besides, if I'm going to go to the trouble of rebuilding the head, it ought to show it.

Saturday was devoted to reassembling the head and installing new flaps, springs, gaskets and shaft packing. Although the US Navy's little guide to onboard repair of the Skipper head(http://www.usna.edu/Sailing/newsite/resources/documents/navy44s/info/headrepair.pdf) said that the most difficult part of reassembly was remounting the base plate (because of the need to compress the foot pedal spring), I was more concerned about getting the piston back into the cylinder. It had taken a surprising amount of force to pull it out, and I didn't want to damage the leather piston cup seal. Although a new leather cup came with the rebuild kit, two different sources said that changing it is a very difficult job, "best left to professionals." So, I decided to reduce the friction of the piston and cup against the cylinder wall as much as possible. I conditioned the piston leather with Dyer's Special Blend Oil (http://www.carldyers.com/ ), sanded the cylinder wall with 400 grit paper to get rid of deposits and roughness, and then buffed it out. In the process of doing this, I noticed that the top of the cylinder opening appeared to have a flat section. Upon closer inspection, I could see that the mounting flange in that location was flattened on the edge and bent up. Apparently, at some time in the past, someone had dropped the heavy assembly on that edge while rebuilding it. That would explain why it was so hard to pull out the piston. Without a sizable machine shop and the skills to use it, there was no way I could do a proper fix. The head pumped fine before, so if I could get the piston back in, it should work fine again. Nonetheless, I tried to mitigate the damage as best I could with a big hammer and wood blocks, followed by a little light grinding on the mounting flange. I didn't want the base plate joint to leak due to a bad seal caused by a flange that wasn't perfectly flat, so when I remounted the base I used non-hardening Permatex on both sides of the thin paper gasket. Just before my attempt at re-inserting the piston into the cylinder, I lubricated the cylinder wall with some light oil. I was able to push in the piston about 3/4 of the way, but then it wouldn't budge, even while twisting it and pushing down with as much force as I dared. I tried a few light taps with a hammer and it popped right in, dropping all the way to the bottom of the cylinder. Apparently the distortion of the cylinder was limited to only the section just below the rim. The rest of the assembly was straightforward. Even screwing down the base plate wasn't especially difficult; I used a webbing clamp to hold it in place against the pressure of the foot pedal spring.

While Sunday was still cloudy, the wind had died down and although there was some possibility of rain, it remained dry. I headed to the boat to install the rebuilt head and see if I could connect the troublesome plumbing for the sink drain and shower sump. I did get the head installed and it functioned properly, but it had a couple of serious leaks initially. One was from the mounting bolts for the raw water inlet manifold, the other from the pump handle shaft. I cured the former by making some rubber washers by splitting a couple of rubber grommets I had on board and installing them under bronze washers. I was able to reduce the latter leak considerably by tightening down the shaft packing nut. Although I cranked the packing nut down as tight as it would go, it still leaked about a drop for every ten strokes of the handle. Although I had used the new cylindrical packing material supplied in the service kit, it seemed to be missing a packing washer shown in the exploded diagram. The old material I removed was conventional stuffing box packing wound around the shaft, so that didn't offer any clues. To cure the leak completely I may have to add a ring of stuffing box packing to the cylindrical packing already in place.

The payoff for all this yucky work that many might consider unnecessary is that I now feel like I have a pretty good understanding of how this head is put together and how it works. I will know how to deal with future issues much more efficiently when I may not have the luxury of being able to do it at my own pace in a nice shop that isn't rockin' and rollin'.

All in all, it just wasn't a good day for leaks. When I checked on the leaks that had led to water on the port fuel tank and engine room bilge, they had reappeared, despite all my work to staunch them, with no discernible source. I'll just have to resort to a good soaking with the hose sometime when I can watch and wait to try to locate the source.

While I was finally able to fit one end of the troublesome T fitting barb into the sink drain hose by grinding down the barbs a bit and heating the end of the hose in a pot of boiling water, it turned out I didn't have the right fittings to connect the other end. The only other thing I accomplished was to make patterns for some aluminum trim I plan to add to the inside of the pilot house windows as a hopefully simple fix for the leaks that dribble onto the teak nav area. Stay tuned to see if it works....