I am trying to cast some rattlesnake blanks. I purchased a silicone mold that appears to be working very well. I started off by painting the brass with camo colored spray paint and let it dry a week. I then CA glued on rattlesnake skin (tanned with glycerin process). After waiting 24-hours for the CA to dry, I trimmed the skin even with the ends of the brass. I then applied CA to the ends to seal and let dry for a week. I then cast two blanks using Alumilite mixed at 1:1. I preheated the mold to 150 F. I poured the alumilite into the molt trying to keep all the bubbles out (didn't get them all out so next time I tried something different which I will explain later). Apparently, after the alumilite had set, a "foam" formed right around the skin - wasn't there before set or at least didn't notice it but well noticeable now. After that casting, I tried two different things. Thinking that maybe the skins were off-gassing, I completely coated the skins with three coats of thin CA glue and let dry for one week. While casting, I rotated the blanks inside the mold to make sure that a good coating was on the skin (also trying to get rid of bubbles). Once again, the casting looked good (no bubbles at all) until after setting. Once again, the foam showed up. What's up???? I need some help. Thanks.