An update from the Duwamish
The Worthington Company (1-800-892-6189) does not have any parts for the fireboat Duwamish‘s air compressor. They do stock a lot of parts for old air compressors, but this one is very old and rare. We’ve decided that the best option is to make new valves. One should be made with a grade 8, half-inch washer, machined and lapped. The other should be made with a small piece of sheet metal the same thickness as the original, lapped perfectly flat.
Preparing for the Sobre las Olas job
The Sobre Las Olas‘s cylinder relief valves were sent up to me last week so that I can overhaul them in my shop. First, I tested a few with a high-pressure nitrogen tank to see what pressure they were set to open at. Many of them were actually over-tightened, some of them leaked, and some were completely plugged with soot. I disassembled them all down to the component parts and started cleaning:
I also found that the Sobre has used two different types of relief valves, the old style with a big bell and a brass adjusting screw, and the newer model that’s much smaller and has an exposed spring. Machining and lapping the old style way too much work; since there’s no guide, I would have had to make something that would fit in the body (in contrast, the new valves have a guide about an inch above the seat). Luckily, Dan had nine of the newer style in the shop, so I chose to overhaul them instead. This also makes all the Sobre‘s valves the same style and therefore interchangeable. As with all the engines I work on, I try to make all the parts the same so that the spares really are spares.
Even using the newer style, the valves were still tough to seal. The seats were all very wide and had lots of pitting. Most required me to narrow the seat by using a five-eighths reamer with a straight end. I ran that down to bring the top down, then I used a tapered reamer to widen the opening. I did this until all the pitting was gone. A few took machining to create the 90-degree edge for the valve to seat in. After that, I lapped them all, set the spring pressure to an opening pressure of close to 800 psi, tested them using nitrogen, and finally set the spring again for exactly 800.
The good ones held to 800, then make a “chatter” sound as the pressure is increased over 800. The bad ones leaked or gradually opened at 800, making a “squish” sound. I spent hours fussing with them until they were all tight and most chattered. Some were still a little squishy, but much better than they had been. I also grabbed a new water collection manifold from Dan’s shed. In the middle of the night before we left, Lia and I nailed together some crates and packed everything up:
I flew out at 0730. I’ll write about the trip next week.
Responsible boat brokerage
I don’t plan on ever owning a boat bigger than my yacht (a 10′ aluminum skiff), but if I did, and then I wanted to sell it, I’d pick my broker carefully. He or she would need experience, knowledge, and a realistic view of ownership to find a buyer capable of taking care of the boat, and the patience to resist a quick easy sell to the first person willing to sign the forms.
From what I’m seeing these days, though, this selectiveness would really limit my choice of broker. A service that should be o honestly match a buyer with a seller to smoothly transfer ownership of a boat seems increasingly hard to find.
In my experience, many brokers take the easy way of selling a boat: they find a sucker who will eat up the vision of gloriously standing at the helm of their very own yacht, which only needs “a little” repair to make that cruise to Baja. Of course, we all know how these stories end (or you should, if you’ve been reading this blog).
Now, I’m all for suckers getting what they’re due (is there a better way to learn than to screw up and have to fix it?), but not when it’s at the expense of the boat and of my reputation. With brokers who just sell this dream, anyone who is asked to survey or repair the boat becomes the enemy. The broker will just keep weaving a dishonest dream of “oh, she’s in great condition – and a bargain!” and the proud new owner will get mad at any mechanic or shipwright who breaks the hard truth to them. Those of us in the marine repair business are the ones who have to crush the dreams of proud new owners, while the brokers walk away with the cash and find more suckers.
If you’re looking to buy a boat, you start being a responsible boat owner before you even step into the broker’s office. You should research what it takes to maintain a boat (old, new, wooden, steel, whatever) and figure out how much you will really be able to do on it. You should figure out the price of moorage, insurance, fuel, and maintenance to determine how much boat you can handle, and then you should start shopping. Talk with other boat owners, get invited on a cruise, and ask to come down and see the boat during it’s annual dry dock period (yes, that means that a boat should get dry-docked every year — not just when you can afford it).
Once you’re ready to buy and are talking with brokers, insist on an independent survey of any boat you’re interested in. Use specialized surveyors for each part of the boat (one for the hull, another for the engine, and another for the rig) to get an informed report on the boat’s condition. Question the surveyors—read the books and take the classes to learn enough to tell when someone’s being honest and when someone’s trying to sell you extra work.
My goal and Old Tacoma Marine Inc’s goal is to increase awareness of the superior comfort, reliability, and efficiency of boats with heavy-duty diesels, so that the boats they power are maintained and the owners feel good about their investment. This ultimately keeps me employed, and saves neat old boats from being scrapped or broken just because they were built before 1950. Bad deals or boats sold to those without the poise, guts, or means to take care of them destroys the boats, the engines, and my profession.
OTM Inc Weekly eBay Auction
This week’s prize from the OTM Inc shop is an Enterprise valve: