Post #281229 by Bowana on Fri, Jan 26, 2007 5:12 PM

pdrake: Cool! Those look nice and dark. How did you do it? Is it the clear resin you were using?

Moki: One thing I have not covered in this thread is the topic of silicone. I noticed that there are some bubbles in your mold. They may be only on the top (as air rises), or they could be throughout the mold and maybe in contact with the piece. Ordinarily one would put the silicone into a vacuum chamber to eliminate any air mixed into the silicone before pouring it into the mold. If you don't have a vacuum (and most people don't), you can break up air bubbles in the mix by pouring it slowly and in a very thin stream into the mold.
If there are bubbles touching the piece, you will have tiny little BB's on your castings wherever a bubble was. They usually get caught in the details. You can flick them out with a knife. Hopefully your mold will be okay. If not, you can certainly box the piece up again and make another one.
I will usually wait about 12-18 hours before pulling a GI-1000 mold and pouring it. I would say that, no you do not have to wait 48 hrs. That instruction might be for larger molds that would generate more heat from the casting resin. Since your mold is so small, your castings won't be that hot (heat-wise I mean!).
Let me know how it works!