Re: Obtaining Propane Tanks

[Nathanael Henderson <jude@pconline.com>]

> So does anyone have any tips on obtaining a pressure hull?  Does anyone know 
> of someone to contact that won't be totally wigged out by someone wanting to 
> make a submarine?

   I'm still in the 'idle contemplation' stage (waiting for a suitcase of
money to appear) but I think tank manufacturers would be a good place to
start.    I live by the philosophy of 'speak no evil' when it comes to odd
projects.  Don't tell anybody what you want it for.   Just look for a tube
of mid-grade steel in the size/thickness you want, with end caps to fit
it.   It would probably be easiest to leave the caps off until the
interior was fitted (stiffeners, etc.) then weld them on (or have somebody
else do it for you.)   If you don't have the good fortune of a gas
shielded wire welder it's probably easiest to just have somebody else do
the welding.  (You can pick up a very nice used one for about a grand.)
    As far as using propane tanks, I don't see why that's inherently a bad
idea.   Just be sure of what you're getting (wall thickness and grade of
steel.)    If you use an old tank or can't get metallurgy info on it, you
could probably  still build with it safely as long as you assume a mild
(low grade) steel.  (I can't imagine people are building pressure tanks
out of mild steel, but who knows?)

    A truly ambitious person could try to find an abandoned bulk tank
(used for propane, CO2, anhydrous ammonia, etc.) left by a business going
under.   The largest useable ones I've seen were about 12' diameter and
about 100' long.