I will go into detail about pressure vessels. They are also known as
"paint pressure pots. The idea is to put the entire mold into the
vessel and keep it at 60 psi or higher while the resin cures. This
will squeeze out any bubbles that were introduced during mixing, as
well as prevent ones that form from any water that the resin has
absorbed from the atmosphere. This moisture is the bane of resin
casters, especially those who use urethanes. It makes them foam.
People who get into the high end have heaters on the tanks, and I had
timers on the heaters to gradually ramp down the heat, and small fans
inside the tanks to keep the heating even.
1.
Bob Engelhardt wrote in message ...
James Waldby wrote: [on using pressure during resin casting] ... I think
the main
intent is to more-completely fill the mold. ...

If the mold is completely within the pressure vessel the pressure will
have no effect on filling the mold.
Not true. If the mold was poured at atmospheric pressure, the void
will shrink as the pressure increases. If there is enough resin in the
"sprue" to fill the void, then the part still has a chance. Of course
a good mold maker makes molds that fill thoroughly every time.

Robobass