Re: Materials/parts...

[Ray Keefer <Ray.Keefer@eng.Sun.COM>]

Hi,

> I have not heard of any reason to not use a propane tank, if there is a
> reason please speak up.

I once asked Kittredge why he didn't like propane tanks. Hear is the relavant
excerpt from his reply:

 Re propane tanks and why I don't like to see them used:
        1.  Propane tanks ae for internal pressure.  Submarine hulls are
designed to resist external pressure.  The latter must be framed in order to
ba able to compute the collapse depth.
        2.  There would be a tendency to use an old discarded propane tank
because they can be purchased cheap.  If it was discarded for propane, why
would you want to use it to risk your life in it?
        3.  I know nothing about the metalurgy of propane tanks.  Notch
toughness, carbon content, etc.  I would have to get the melt number of the
steel in the tank and do a charpy test.  By the time I got through, I would
probably spend more money than buying a certified plate of A36 or ASTM
516Gr70 (which I like) and having it rolled.  For a K-350 hull (one man) it
should not cost about $400.  Then it would have to be framed.  Why fool
around with an unknown propane tank?

Regards,
Ray