Silicone Valley
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Soma Foama
Discussion started by Emily , on 19 July 04:34 PM
Okay Ron, start talking! I'm making a tentacled creature (three legs, two arms, simple body & head) but haven't created the mold yet. I was at a local smooth-on distributor to pick up some slacker and they had the foam in so I couldn't resist - a bit pricey though! Anything to start me off?
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Wooops! Sometimes we forget how much our pet armatures like to swim! You may want to consider mixing up a tiny bit of foam and secure the armature in place with it first before pouring the rest. You may also want to consider NOT tearing all the foam off the armature from the bad casting, just trim it down so that it fits in the mold with a gap around it. You won't have to mix up as much foam next time and that reject casting won't be a total waste of material.
Thursday, 22 July 2010 05:33
Doh! The armature was in the mold but not secured to anything other than over the edge to keep it centered. The expanding foam pushed it up and ruined the casting - it's up almost an inch out of it's placement. New casting will definitely have a better way of keeping the wire in place.
Wednesday, 21 July 2010 21:43
First casting - though the venting hole in the bottom came in very helpful - the first batch I mixed I stirred for too long so it was already foaming by the time I started pouring in and only went around 3/4 of the way into the mold. So I did a small second batch from the bottom hole that fixed it up. And yep about 1 tentacle at a time - it seemed a practical way to go since the body of the puppet will be covered and so seams are okay.
The skin I painted in is around 1-2mm thick - I did it that heavy on Henry (I should post pics of him too) and haven't had any tears yet, though that was with slacker inside - I might increase it a bit for the foam. You mentioned gripping puppets with your nails more and I don't do that much so maybe that's why they haven't torn. (I have had finger wires poke through eventually but sil-poxy fixed that right up.)
The skin I painted in is around 1-2mm thick - I did it that heavy on Henry (I should post pics of him too) and haven't had any tears yet, though that was with slacker inside - I might increase it a bit for the foam. You mentioned gripping puppets with your nails more and I don't do that much so maybe that's why they haven't torn. (I have had finger wires poke through eventually but sil-poxy fixed that right up.)
Tuesday, 20 July 2010 21:16
Excellent! And was that your first casting or did you have any bad trials prior to this? I'm not exactly sure why you have the armature partially sticking out of the mold in that one photo but, I can easily see that it's the product of a grand plan! (one tentacle at a time me suspects?) How thick of a Platsil skin did you give it prior to the foam casting? When I do it, I try to give the whole thing a thickness that's more than paper thin because I know Soma-Foama can rip with a little abrasion so, I trust a thicker skin more.
As for switching photos around, I think you can delete the ones you already added and start a new album aside from the one I started. If you can't remove the ones you already posted (because time to edit runs out or something) just ask me to delete them for you - because I am the almighty administrator of this group, I can always edit.
Silicone foam has come to Earth at last! Doncha love it? :)
As for switching photos around, I think you can delete the ones you already added and start a new album aside from the one I started. If you can't remove the ones you already posted (because time to edit runs out or something) just ask me to delete them for you - because I am the almighty administrator of this group, I can always edit.
Silicone foam has come to Earth at last! Doncha love it? :)
Tuesday, 20 July 2010 19:41
I posted some photos of my first test with the Soma Foama - overall it's great, very short working time (less than 1 min!) but very light - I'm actually remaking the armature because I built it to move a heavier puppet and it's quite light with this foam.
I'm putting a few comments on the photos - sorry, probably should've put them in another folder to keep them organized. (Any way to move them after the fact?)
I'm putting a few comments on the photos - sorry, probably should've put them in another folder to keep them organized. (Any way to move them after the fact?)
Tuesday, 20 July 2010 19:19
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