[Milsurplus] DIY Vacuum Chamber

[Bob kb8tq]

Hi

If you head over and get a “paint pot” at the big box store, they are good to at least 50 PSI. They
also come in bigger sizes (for more money …. how odd … :) ).

Same deal, works with pressure or vacuum.

If yo want to go “one step up” get a good vacuum pump and put a heat pad under the whole rig. 
Things will get *very* dry.

One side note: With any vacuum approach fancy or simple: you also will find out if anything in 
the radio is “unhappy at altitude” …. not 100% sure that is the sort of research I would dive into.

Bob

> On Sep 22, 2026, at 3:14 AM, Jim Whartenby via Milsurplus <milsurplus at mailman.qth.net> wrote:
> 
> When a pressure cooker is cooking, it has about 15psi on the inside pushing out.  When used as a vacuum chamber, the 15psi is on the outside pushing in.  Evidently, the aluminum container can't tell the difference!  <grin>
> Jim
> 
> Logic is a systematic method of coming to the wrong conclusion with confidence.  Murphy
> 
> 
> On Monday, September 21, 2026 at 04:50:31 PM CDT, Facility 406 <facility_406 at bruteforcedevelopment.com> wrote:
> 
> On 9/21/2026 13:19, Jim Whartenby via Milsurplus wrote:
> > One way to easily remove water vapor is with a vacuum.  One can easily
> > convert an old pressure cooker into a vacuum chamber for perhaps under
> > $30 if you already have a hobby compressor / vacuum pump.  The holes in
> > the cover are national pipe threads so just remove the old hardware and
> > substitute a vacuum gauge, ball valve and a tubing adaptor along with a
> > new gasket seal.  Plug any unneeded holes with the appropriate NPT
> > plug.  I use a small Gast air compressor / vacuum pump with good
> > results.  This example will hold a decent vacuum for well over a week.
> 
> I've thought of that in the past, but have been worried of the bottom
> imploding.
> 
> One idea I had was to bolt an Al plate to the bottom, something maybe
> 3/8" thick.
> 
> Kurt
> 
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