Hi,
I'm building a small underwater tethered / robot / submarine /
doo-hickey and I need a cheap way to pressure test the individual
components to make sure they don't leak. Max diving depth will be 70'
which is around 32psi and each component will be no larger than 6"x6".
I know each component should be tested to 1.5X to 2X its expected
range.

Anyway, my thought was to fill some already pressure resistant device
such as a pressure cooker or autoclave chamber (hello ebay!) with water
and then use shop air to increase the pressure. I don't need a viewing
window as I would basically take it up to pressure, leave it there for
a few hours, relieve the pressure and then check to see if anything
leaked.

Questions:
1) Is this concept of pressure testing sound?
2) Is there a cheaper way to do it?
3) Most importantly, is there an easier way to do this?

Thanks and please resist the urge to point out the 100's of other
failure points that I will be facing in this project such as watertight
bulkhead fittings, ballast systems, propulsion, electronics, stability
control, corrosion, battery systems, faily safe safety systems, etc,
etc...

-M