by Anvils Hammer » Tue Jan 31, 2012 6:14 am
So Ive been thinking about how to make molds a lot recently..
I need to go from having a split mold of a single part, to having a split mold which can create 15-30 copies of that part in one go, for production casting.
My process, which I think is the best way forward, is to make a split mold, get 5 casts, make a split mold, get a number of sprues, each each with 5 parts, and put all the sprues in a single "mold block".
I can use a different number of "master sprues" depending on how high I expect demand to be for a given component.
The one problem, which I discovered to day, is that cutting the "split" around complicated shapes like axes and guns, is a massive pain in the ass. It took me at least 15 minutes to get 5 rifles out of the master mold, and im more likely to cause damage to the mold.
Making a producton mold with 15 copies of the rifle would take forever to cut the splits and they would probably not be that clean.
So I had an idea.. lost wax casting.. its not a new idea.. it was around long before silicone and polyurethane.
I think if I pour the master molds using molten wax instead of resin, I should still be able to get the parts out fine, and the detail level will be the same (pressure cast the wax as normal...)
When the silicone mold has cured around the wax masters,I can dump the whole thing in hot water for 5 minutes, then cut the split lines neatly and instantly.. as the masters are in liquid state again..
For production of the molds with 5 parts, Ill keep using resin, but for the production molds, I think filling the master molds with wax might work really nicely!
Worth experimenting with anyway..
Has anyone else tried/considered this? am I totally mad?
AH