lysander - 11-8-2015 at 20:29
Any recommendations on a "hobbyist"-grade vacuum dryer?
Magpie - 12-8-2015 at 08:24
I have wanted one of these on occasion. There are details for a self-made vacuum pan dryer in the book on dyes by Fierz-David & Blangey in the
forum library.
I am thinking that one could be made from a pressure cooker. With this a full vacuum can be applied. It could also be easily heated using a
hotplate.
The tough part is the choice of vacuum source, disposal of the noxious off-gases, etc.
ave369 - 12-8-2015 at 10:47
A very crude vacuum drier for small quantities can be made from some vacuum canning sets. In my country there is one with lids that fit any standard
pickle jar. Choose the smallest jar you can find that fits the lid, spread your substance to be dried on its bottom, and put into it a small beaker of
something that dehydrates the air (e.g. P4O10). Close the lid and start working with a pump. Keep pumping the air out. Then
wait. You can open the lid after an hour or two pass. If heating is needed, put the evacuated jar on a water, oil or sand bath.
Note: it is possible that the pump that comes with the set does not create the necessary vacuum. This means you'll have to upgrade it. Fiddle with the
piston a bit until a full gas seal is reached.
The smaller the jar is, the easier it is to create vacuum in it, and less chance for it to be crushed by atmospheric pressure. Small jars that I have
can withstand full atmo pressure.
[Edited on 12-8-2015 by ave369]
chemrox - 12-8-2015 at 11:47
I found one on ebay. I don't believe there's a DIY substitute. Mine is set to max out at 30 in Hg. I can pull more by putting a stopper in the air
intake but I rarely do that because I'm guessing it was made that way to protect the seals. Also you need a decent pump and that should be protected
with a trap unless you like to change oil or clean diaphragms.
[Edited on 12-8-2015 by chemrox]