Taxidermy.Net Forum - jawset casting question

Michael. I use RTV silicone with the regular set catalyst - you can use the fast acting catalyst if you're in a hurry. I separate the lower jaw from the skull then remove the tongue. I put the jaw on a half inch layer of High Fiber. I use more High Fiber to build a dam around the jaw about 3/8" from the bone and high enough to have at least 3/4" above the tallest tooth. You'll have to fill in where the throat starts. I do the skull the same way. Place it upside down on some High Fiber then build around it leaving at least 3/8" clearance and high enough to have at least 3/4" above the canine teeth. Making the dam a little higher won't hurt. Be sure there are no cracks in the high fiber or the silicone will find it and leak out. You could also use some sheet material - tin, aluminum, plastic milk jug, etc - to form the outer dam but have to still use the High Fiber as a base and to mold around the jaw/skull and any voids. I've used both POR-A-KAST and Smooth-Cast 300 to make the castings. Hint: Pour some of you casting medium in to the deeper tooth openings and use a pin to make sure there are no air bubbles in them, then pour the rest of the cast. You won't need any separator to remove the castings from the molds. When the molds are first cured you can wash them in warm water and liquid detergent before using them the first time.