What one needs to realize is that a yacht finish, esp. with a steam power plant, is a labor of love... and that historically the vast majority of steam propelled craft were "rough and ready". I find that minor damage is much less obvious, and more easily repaired, with an oil finish rather than laye...

My experience with such is that if they're fine enough to stop embers, they plug pretty quickly, esp. with an oil fire just being started. However, this may not be an issue for you; it depends on what you're burning. We had a steamboat meet at Donner Lake (near Lake Tahoe) where we were required to ...

Ken, I see what you are saying about the 48" max dimension on the sheet stock. But when I enter in a custom cut of 1" x 76" it accepts it. I'll call them on Monday and see what is available. I have a backup plan of going to stainless. Any larger sheet metal shop has it in sheets 96" long and can sh...

Since you're going to be running in salt water all the time, this will turn green pretty quickly unless you polish it frequently.

- Bart

The reason that yield strength doesn't matter for some geometries is indeed that as the part flexes, the loads increase dramatically. A good example is when standing on a aluminum soda can a very slight (elastic) deflection caused by gently pressing on the side of the can causes the can to collapse....

v belt works fine; a #35 chain drive isn't noisy if you use 20 teeth sprockets or so and run it at crankshaft speed if you do use a v-belt, don't use tiny pulleys either. A 3VX section belt will work well, has low losses and you can make your own pulleys to suit on the lathe from 1/2" Al plate. - Bart

Only if it is below water line.... and I don't recommend this, because you'll suck silently salt as the boiler cools if the check hangs.

- Bart

When Otter was non-condensing, I just exhausted out a through-hull that exited above the waterline. I used water heater hose for this; it worked well enough and never gave any problems. Do be careful to not oil the engine interior as this will produce a slick.

- Bart

When I lay up the boiler on Otter, I fill it with water directly from the hose after putting a charge of TSP into the boiler. This minimizes the amount of entrained air. Since Otter lives on a trailer, this is a normal part of preparing the boat to go back under it's shelter in the side yard. - Bart

Well, I'd be careful. Washing machine hose isn't exactly rated for either 350 F or 150 psi...
suddenly holding a lot of steam in your hand isn't that fun.

- Bart