Reworking the Mold PART 2

Side View of reworked mold with old mold cured to it.

 When I first started casting, it was mentioned to me that some people have been experimenting recycling their old molds.  Grinding them up and reworking it in with fresh silicone to help 'a' recycle and 'b' cut down on costs.

This is something I have been wanting to try, but without a method to grind up the silicone I wasn't sure how.

Reworked mold with old mold cured to it.

Then I became concerned chunks of silicone would trap air against the piece being molded.  So I had been toying with the idea of using only a thin layer of fresh silicone followed by a thicker layer of recycled and reworked silicone.  With no effective grinder, there was no way to try...

I JUST LOVE LEGO.   Lego provides a standard.  It gives one a way to remake the mold frame to exactly the same  dimensions EVERY time. 

Picture of reworked mold

The urethane is very hard on this mold.  I am asking a little "tit" less than 1/16" in diameter to resist being pulled out of a small hole.  Well that "tit" ripped out again.  I have 4 chest canopies left to make...then it hit me.  I am almost out of silicone and I didn't have enough to make a nice beefy mold.  But I did have other crapped out molds I wasn't using.  So I poured some fresh silicone to remake the 2nd half of the mold again.  But the layer was thin.  I am almost out.  Then I grabbed an old worn out mold made with a LEGO frame that has the exact same dimensions and seated it on top of the fresh silicone and let the 2 cure to each other.

 This is NOW, the top of the mold.  Not the casting cavity.

It worked.  I have beefed up the mold using one of my old worn out molds.  This is a VERY cool discovery for me.  Very Cool.