clayslinger
Well-Known Member
I use a vacuum chamber for most everything. Rubber and resin. You need to use a resin with a longer setting time and also have a large enough vacuum pump to work quickly enough for your application.
Your mold has to have the room for the resin to expand to while in the chamber and the chambers need to be large enough for the job but not a 5 gallon size to evacuate a golf ball sized cast. I use half a dozen different sized chambers.
I use pressure only occasionally for larger solid pieces that I can't fit into a vacuum chamber.
For some large hollow casts I talc the mold and roto cast by hand or use a fiber filler and brush it in. I do not vacuum the resin in either of those occasions.
The key is to use a big fast vacuum pump. Getting the rubber or resin to rise and collapse in seconds makes all the difference.
That's my two cents!
Chuck...
Your mold has to have the room for the resin to expand to while in the chamber and the chambers need to be large enough for the job but not a 5 gallon size to evacuate a golf ball sized cast. I use half a dozen different sized chambers.
I use pressure only occasionally for larger solid pieces that I can't fit into a vacuum chamber.
For some large hollow casts I talc the mold and roto cast by hand or use a fiber filler and brush it in. I do not vacuum the resin in either of those occasions.
The key is to use a big fast vacuum pump. Getting the rubber or resin to rise and collapse in seconds makes all the difference.
That's my two cents!
Chuck...