Dear build diary (and anyone else still paying attention)… IT IS NOW PICS TIME!!
Apparently, I didn’t get any pics of the forearm before I started molding it, so here are some I got after the de-molding. The sculpt survived fairly well. There is some damage, but these pics are a fairly decent representation.
Silicone of choice for the mold? Dragon Skin! Since it was over a year old I decided to test it by making some registration keys. If it fails, it’s a waste anyway, but if it works… hey, registration keys! And it worked!
So, here are the mold-in-progress pics, layers 1 (print layer), 2 (reinforcement and registration keys), and 3 (final smoothing and reinforcement), respectively (and, I must say, I LOVE my sampler pack of Silc-Pig silicone pigments):
A word of note, Dragon Skin bubbles… HORRIBLY! I’m hoping the bubbles didn’t affect the print coat too much but, for the future, I am seriously considering investing in a vacuum degasser.
And now the shell/mother mold, and I have to give BIG MAJOR HUGE props to
BLACKULA727 and his UNBELIEVEABLY AWESOME Elite sculpt thread!! The mother mold is made ENTIRELY of
Free Form AIR Lightweight Epoxy Putty, an idea I got (once again) from
BLACKULA727's SUPER MAJOR MONDO AWESOME Elite sculpt thread (seriously, check it out if you haven't already). This stuff is very, VERY strange, and kind of surreal to work with. Feels a bit like floam. It’s extremely light, stable, resistant to gravity, easy to shape, smooths and blends immaculately with a little bit of water, and seems to be pretty strong when cured. You don’t need to mess with clay walls, mixing cups, majorly noxious fumes, or, with a little care, even barriers like foil or plastic wrap to prevent self-adhesion with cured parts (I used generous amounts of Vaseline from the Dollar Store and a $5.00 spray-on release agent). The only real drawbacks are these, and they are TOTALLY mitigable… first, it’s SUPER sticky (fixed with a bit of water), portioning involves a bit of ambiguity (does not measure well by weight, but you can totally eyeball the volume with no adverse effects), semi-toxic (no respirator required, but you should have good ventilation), and the instructions say that you should wear vinyl gloves (though I used nitrile, which I find superior to vinyl in every way, with no problem) when mixing (apparently it’s okay after it is thoroughly mixed?? After reading the MSDS, it looks like part A is inert, while part B is more hazardous). For what it’s worth, though, I may never go back to anything else for mother molds, like EVAR!! Seriously, the stuff is AMAZING, and comparable in price to Plasti-Paste. So, thanks again to BLACKULA727!! Oh, yeah, and here are the pics:
The pink bits you see there are shaved-off pieces of Rebound 25 registration keys left over from the shoulder bell mold. An idea attributed once again to BLACKULA727, when pulled out, these bits of silicone form small cavities into which a screwdriver may fit. This technique provides convenient pry-points for help in separating the two halves of the mother mold. And the ribs you see in the shell add reinforcement at those points so the mother mold doesn’t snap bits off during the prying-apart process. And, I must say, it worked SPLENDIDLY!
For this mold I chose to try not cutting the silicone, and just pulled the thing off. It seems to have worked so far. Dragon Skin is supposed to have excellent tensile strength, to help prevent tearing, and I fervently hope this holds true. Sure, it de-molded just fine, but we’ll really see after a few casts. A few casts, you ask? Why YES, actually! Even though I only need one cast of the forearm for the actual suit, it’s a small and simple enough piece that I’m hoping to try a few things before I retire it.
So, thanks again for looking, and stay tuned for the casts!