Oh boy, long time no see!
I hope life is treating you fine.
First, let me put you in context; a little while ago, I was chatting with my fellow performer and great friend Daniel while preparing our duo's show for the St-Jean-Baptiste's eve in Chibougamau. We were talking about things we would like to implement in the show, and handmade goods we might want to sell later on, because T-Shirts are nice, but sometimes they just don't cut it.
Daniel had enjoyed Steve and thought it might be nice to have our own little creepy head hunter stand from which sell shrunken heads. Now, Steve was mostly an experiment which somewhat failed as much as I'm concerned, and his mold was a wreck, so I decided to start from scratch, make a better sculpt, a better mold, and work on making the finishing of that thing as fast and good looking as possible, while keeping the costs down. I've worked it out, and now I'll let you know what I did, in a tutorial more explicit than the first one. (I took pictures this time! yay!)
So, here we go, after the jump!
First of all, I had to find the time to do all that. I got my wisdom teeth pulled out last week (actually, carved out would be a better term), and what is a boy to do when you look like a hamster with his face stuffed and you're constantly buzzed on painkillers? do arts and crafts!
Thus, I dug out my oil-based clay, sculpting tools and all that jazz and went to work in sculpting a small shrunken head. I won't go step by step in how I did it, because I tend to just slap hunks of clay together and work something out from it, so here's pictures of the finished sculpt with a shot glass for scale. I'll put links at the end to more information on sculpting skin and the like.
Once your sculpture is done and you're happy with it, if you used oil based clay (which I can recommend enough, over water based, for this kind of project), put your sculpture in the fridge or the freezer for a short while. That will harden the clay temporarily (heat will soften it) so you can work on the mold without risking damaging the detail of the sculpture.
First step in making the mold is to create a retaining wall. For this, I strongly recommend using water based clay. Why? because it is quite soft at room temperature, and unlike oil based clay, it will wash off with water, which makes removing the wall very easy once the first half of the mold is done. That, and the fact that water based clay won't fuse to oil based clay, of course.
You want your retaining wall to be as smooth as possible, with the edge as clean and straight as you can, this will make a much cleaner cast afterwards. I also like to build a small wall on the bottom to retain the plaster.
Once your retaining wall is done, it simply is a matter of mixing a batch of plaster and applying it. Oh wait, no, it's a bit more complicated. While the plaster is still at it's most liquid, you'll want to gently brush it on the surface of the sculpture so it runs easily in every nooks & crannies, preserving the most minute detail. Make sure no air bubbles form at that time. Continue adding plaster as it thickens, until you have a nice, thick wall built up, at least 1'' thick everywhere. Be aware that it might be easier to mix multiple small batches of plaster instead of a large batch. This will give you more time to work on your mold.
Wait a few hours for the plaster to fully set. Once that is done, remove the retaining wall, clean up all residual clay with a soft brush and water, so the sculpture is nice & clean. Afterwards, I recommend putting small wedges of clay on the outermost edges of the mold. These would be what we call "mold keys", and removing them once the mold is completed will give you nice holes on which to grip the mold to separate the two halves.
Once that is done, you want to cover the plaster edge with a thick mold release so the next half of the mold don't stick to it. I recommend Vaseline, but personally, I used dish soap. Why? Because I'm fuckin' ghetto, that's why. And I didn't have any vaseline at home.
Afterwards, it is simply a matter of restarting the process with the other half, so you end up with a full 2 part mold.
Then, you just need to wait for it to set and dry. Depending of the thickness of your mold and the temperature and humidity of where you work, it can take anything from overnight to a few days to be full dry. Once it is, remove the clay chunks you put earlier (the mold keys), and using the openings created, gently pry the mold open. Remove your sculpture and clean up your mold as well as you can.
For casting, if you use latex like I do, you can put mold release on it, but personally, I only use a few coats of sealant to make it less porous. Try to stay clear from oily mold release compounds, because it might interfere with the setting of the latex. But normally, a coat or two of sealant should be more than enough. Varathane works great. I used hairspray. Why? because I'm sooo ghetto, that's why. But mostly because I didn't have any spray sealant. It worked like a charm.
The next step, once your sealant is dry, is to close up the mold, keep it shut with rubber bands or whatever else you see fit, and fill it with liquid latex. And I mean FILL it.
Don't worry, I'm not crazy. The point is that if you fill your mold to the top, shake it and knock on it a bit to remove air bubbles, and wait for about 20 minutes to half an hour, a skin will have formed inside the mold. The next step, naturally, is to empty the mold back into the container of liquid latex. It might take a little shaking and patience to get all the excess out. You want a uniform skin to remain inside, though.
Like so. Ain't it pretty? Now all you have to do is to let it cure somewhere dry and warm. I recommend waiting at least 24 hours before demolding, just to be sure.
You'll know it's ready when the latex skin is yellow all around. If there are still some paler or whitish spots, wait some more, it's not fully cured yet.
Once it's dry, you'll want to dust the inside of the latex skin with talcum or baby powder. Cornstarch will do, too. The goal is simply to remove the tackiness of the latex, so it doesnt stick to itself. Gently unstick the skin from the mold, add some more powder on that side too, and then open the mold, and remove your latex copy, while being careful not to chip or tear anything.
You should have something like that as a result. Neat, huh? I'll be back in a day or two or three with the finishing part of the creation of this head. Until then, take care!
UPDATE: Part 2 of this tutorial
I recommend you guys head over there for a little reading:
History of the Shuar
The Effects Lab - on sculpting skin detail
3 part detailed mold making tutorial by Ron Cole
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