Dewax by pressure cooker

how much water would be needed to evacuate the wax and still have
enough water to catch the wax?  If the pressure cooker drys out,
one would have fumes from the burning wax; or have I misunderstood? 

G’day; A pressure cooker does not ‘use’ very much water. About 1
1/2 inches of water would be more than sufficient. The point is
that you put the cooker containing the water, and with lid fastened
and weight off on a good hotplate and as soon as a jet of steam
issues from the vent, the weight is put in place and the heat turned
down so that steam just burbles from under the weight. No greater
heat is necessary and won’t get the steam hotter than 121C; more
weight would be necessary for that. Just keep it gently boiling and
burbling. But you are well advised to stick to the weight provided
and no more. There should still be some water left after about 40
minutes, so it should not boil dry. In fact 20 minutes after placing
the weight should be sufficient to melt out nearly all the high
melting point wax. Just don’t go off for a beer and get talking to
your mates. As I mentioned earlier, small towels placed to ‘cook’ in
a loosely fastened oven bag can be properly sealed after it becomes
hand hot and the towels will be dry. So the investment too should be
fairly dry. They will be surgically sterile if left in the sealed
bag. (hint for the first aid box?) – Cheers for now,

John Burgess; @John_Burgess2 of Mapua, Nelson NZ