Our Otter uses a 1/2" angle globe valve as a main steam stop valve, and a strainer w/ wire mesh to remove any scale, etc, carry-over that would damage slide valves, etc.... and the throttle valve is a 1/2" angled bronze globe valve w/ a metal-metal seat. this combo works very well.

- Bart

87gn@tahoe wrote:Another method is using rope, wraped with fabric soaked in aribel (sp?)

The stuff you're thinking of was Arabol.... as far as I know, it's no longer manufactured. There are lots
of substitutes....

- Bart

Aside: Does paypal work in the U.K.? They would do well to set that up...

- Bart

Painted rope works well enough to keep me from getting burned, and there's something about a steam line with Turk's heads at the ends, all spiffy and white.... Barbie (my wife) does all the knot work on Otter. Around here, woven fiberglass tape for insulation is a little more difficult to find, and ...

For non-superheated steam pipes - cotton rope, painted with travel trailer roofing goo (a white rubbery compound). For manifold and weldments to complex to cover w/ rope, I use a moldable paste insulation and cover it after it dries with fabric strips soaked in lagging adhesive or that roofing patch...

That's a nice engine and some interesting machining techniques. I note that Al is using aluminium pistons. This will keep the reciprocating weight down, but somehow I had a notion that iron should be used with steam. Anyone? John Aluminum works fine for steam engine pistons at traditional pressures...

On a larger boat, an evaporator is simple enough to rig... you can heat it via a steam coil. Rig a
modified pressure regular to keep from exceeding 30 psi in the evaporator; otherwise the salts
form a hard crust.

- Bart

Hmmm my experience sailing in the San Juans is that the winds are far more fickle than my boiler & power plant :lol: The design trade-offs (space, shape of hull, etc) needed for successful sail propulsion are substantial... you're better off squirreling a small outboard in a locker and using that if...

You left out a very handy option for smaller boats - the push-pull tiller, as you would see on a sailing dingy.... mine is a tapered 3' piece of oak fastened with a shop made bronze & stainless swivel to a lever arm on the rudder shaft: inexpensive & simple, doesn't whack people upside the head. Thi...

I have a copy of David Gerr's Propeller Handbook - it is indeed excellent. Some rules of thumb for steam boat designs from various places (displacement hulls, low power): 1) Use the largest possible propeller diameter that will fit the hull. 2) try for a 1:1 diameter pitch ratio if possible - it's t...