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Gene,
Emily, I am excited to see how this turns out. Please take lots of photos and post them.
Monday, 19 July 2010 20:49
I mixed a tiny amount in a plastic cup and I love this stuff! I couldn't stop squishing it.
I think for the puppet I'm doing I'm going to cheat and make one master mold for a tentacle and cast each leg/arm out of that - the main body section will be covered so it'll be a good way to learn to use the foam (painting a layer of dragonskin in first) Thanks for the idea of tinting the foam! Will do for sure.
I think for the puppet I'm doing I'm going to cheat and make one master mold for a tentacle and cast each leg/arm out of that - the main body section will be covered so it'll be a good way to learn to use the foam (painting a layer of dragonskin in first) Thanks for the idea of tinting the foam! Will do for sure.
Monday, 19 July 2010 20:42
Yes I did (foolishly) have a good idea what I was getting into when I started this discussion and this group. I know it will probably eat up more of my time than I might want to spend but, these stop motion websites have given me so much encouragement and so many new friends - I'll continue to give as much as I can in the time I have.
The skin layer I mentioned is an opaque coating of Platsil Gel 10 over the entire reproduction surface of the mold. You can cast with no skin coat at all but, I tried that and it looks good at first but, just foam is weak and rips easily. So you need a skin of Platsil painted on in several layers so that it appears to be a complete coating. (until you can no longer see any of the mold surface showing trough the rubber)
The skin layer I mentioned is an opaque coating of Platsil Gel 10 over the entire reproduction surface of the mold. You can cast with no skin coat at all but, I tried that and it looks good at first but, just foam is weak and rips easily. So you need a skin of Platsil painted on in several layers so that it appears to be a complete coating. (until you can no longer see any of the mold surface showing trough the rubber)
Monday, 19 July 2010 19:58
Gene,
Ron, when you say paint in your skin layer, are you using soma foama or do you paint in a coat of platsil gel 10? If you are casting a human figure with fingers, do you allow a air hole at the end of every finger? So many questions… Did you have any idea what you where getting into with this discussion group?
Monday, 19 July 2010 19:29
Hey Emily, well for starters you're going to need vents in your mold at the ends of the extremities. (meaning the tips of the tentacles, top of the head and anyplace else that's limb-like) So basically you need a tube leading off the ends so that the foam has somewhere to push air out of the mold as it expands.
To cast your puppet you'll need to start with the mold open and a skin layer pained in. You mix your foam up as quickly as you possibly can, that stuff kicks FAST! Pour it into the center of the mold (largest body area) set your armature in place, then close and clamp your mold... you have 50 seconds!
But! there is good news - there's another additive you can buy called 'Slo-Jo' that is a retarder that will double the amount of working time you have. (also from Smooth-On) You'll need to mix up more than it will take to fill your mold so there will be some overflow that will pour out of those vents.
If you were to cast a puppet that has just way too large an area to fill in that short amount of time, (as I did on that Brisk Iced Tea ad) then you can build up some of that foam over the armature before you cast and trim it so that it mostly fills the mold. That way you'll have a minimum amount to just fill whatever gap there is between the armature and the mold surface.
I would recommend tinting the foam just as you would any rubber that you fill with because it will manage to squeeze between the mold halves and there will be flash to trim off. So if you don't tint it, that will end up being a white line and you don't want that right? So add the tint to one half of the foam base.
Something I really like about the foam is that it bonds perfectly to the Platsil Gel 10 so, there's no worry about it peeling away or anything. And yeah it's a bit on the expensive side but, it expands about 4 times it's liquid volume so, that small 'trial' kit will actually yield about a gallon of foam.
When I got my first kit of the foam, I mixed up a small batch and poured it into an old mold that I didn't care about, just to get a feel for how it works. I would recommend you do that because that gave me a bit more confidence about what I should expect when I attempted my first 'real' casting.
Happy Foaming! :)
To cast your puppet you'll need to start with the mold open and a skin layer pained in. You mix your foam up as quickly as you possibly can, that stuff kicks FAST! Pour it into the center of the mold (largest body area) set your armature in place, then close and clamp your mold... you have 50 seconds!
But! there is good news - there's another additive you can buy called 'Slo-Jo' that is a retarder that will double the amount of working time you have. (also from Smooth-On) You'll need to mix up more than it will take to fill your mold so there will be some overflow that will pour out of those vents.
If you were to cast a puppet that has just way too large an area to fill in that short amount of time, (as I did on that Brisk Iced Tea ad) then you can build up some of that foam over the armature before you cast and trim it so that it mostly fills the mold. That way you'll have a minimum amount to just fill whatever gap there is between the armature and the mold surface.
I would recommend tinting the foam just as you would any rubber that you fill with because it will manage to squeeze between the mold halves and there will be flash to trim off. So if you don't tint it, that will end up being a white line and you don't want that right? So add the tint to one half of the foam base.
Something I really like about the foam is that it bonds perfectly to the Platsil Gel 10 so, there's no worry about it peeling away or anything. And yeah it's a bit on the expensive side but, it expands about 4 times it's liquid volume so, that small 'trial' kit will actually yield about a gallon of foam.
When I got my first kit of the foam, I mixed up a small batch and poured it into an old mold that I didn't care about, just to get a feel for how it works. I would recommend you do that because that gave me a bit more confidence about what I should expect when I attempted my first 'real' casting.
Happy Foaming! :)
Monday, 19 July 2010 17:16