Sunday, June 10, 2012
BJD Silicone Molds and Junk Casts
FYI-- One and a third gallons of AM 128 RTV Silicone Rubber makes 3 complete molds (upper torso, lower torso, head) and 4 small half-molds (hands, head cap, both feet in one mold), plus ball-joint junk molds used in elbows, knees, shoulders and hips, for a 1/4 scale ball jointed doll. I'll need to buy another gallon to finish off the small molds, and to mold the arms and legs. And this is just for junk-casting! I'll need another round of silicone to cast the Masters.
Wish I hadn't wasted the first 2/3 of a gallon a few months ago on half-parts I never used! I live and learn, I guess, especially with materials I've never used before. Now I'm hoping I didn't screw up anything important, and that the very EXPENSIVE molds I've finished work properly (i.e. not get stuck together or rip or what have you). I'll know tomorrow. I maybe have enough resin to cast each of the three finished molds a couple times.
Hopefully, too, the original doll parts will survive molding. I'd love to see her completely assembled and finished.
Note 1: I forgot to key-up one of the hands before pouring silicone. I'll attempt to fix this by gouging out a few keys in the flip side.
Note 2: A gallon of silicone doesn't fill up nearly as much mold space as you'd think. I bought what I could afford. No fancy cubic-centimeter estimates here. Just hoping it woulda been enough. Perhaps there was some waste, but I'd rather waste a bit than skimp on the stuff and tear a mold.
Note 3: Now that I thought about it, I coulda keyed up the hand mold right through the wet silicone with the end of a paint brush. It would have filled in the holes. (I just ran into the other room to try it.) Now it's set up too firmly to do that. LOL. Filing that little realization away for future reference...
UPDATE: Two of the molds weren't sealed well enough and started leaking out the bottom. I used clay AND hot glue AND smooth-sided cardboard. Guess I missed a spot. *sigh* Damage control may have been sufficient, but I don't know yet...
UPDATE 2: I ran outta silicone AND resin. I managed a really rough junk cast of the head, upper and lower torso. Both dolls are strung together with a section of chopstick in the head and a rubber band or two tied beneath the crotch. Both dolls hold pretty much any pose (except those requiring limbs :D). You can see the imperfections, bubbles and other nasty stuff really well in the white resin, but I feel better that I at least accomplished this much with her before running out of stuff to work with...
If I sound discouraged, I'm not really. Just tired and a bit disappointed that I won't get all my molds made over my weekend off from work. And poor. ;) Also feeling poor. Now I have to buy another gallon of silicone if I can afford it, and probably some more resin. Thank goodness the mold release will last a while! This delay just means I should work on the remaining parts so that maybe they'll go straight to Master molding... maybe?