Thread: Alternative to Plaster of Paris

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Heya guys,

I just made a cast of a decent sized skull from plaster of paris. (pics to come a bit later when i dries more) the only problem is because its a decent size, it weighs about 8 pounds or so. So my question is, is there anything that acts like plaster, but is much lighter? I tried looking some stuff up online but cant find anything general, might need a specific product name.

So if anyone has used something lighter than plaster for casting, give me a shout im trying to stay away from expanding foam, as im not sure the mold im using could take it. thanks everyone

Bob

What about resin with a hollow sphere filler?
You could also look at rotocasting to create a hollow cast.

edit: Found the wood rotocaster.
~Rotomolder~ Solsylva CNC Plans

How about silicone caulking as is discussed here: Silicone molds?

Been dieing to try it, just have a long list of things to finish before I can start something new.

Hey death, thats an idea, but a costly one. I guess i want the best of all worlds, cheap and light might look into it though.

Thanks bubbles, i remember reading this thread too, but i have the mold. Im not sure filling the mold with silicone caulk would do the trick, but who knows

I misunderstood. In that case, expanding foam does the trick quite well! Not only are they light, but you can kick them around without worrying about breaking them and I would imagine they are also rather water resistant.

Did you consider this:
Rigid and Flexible Castable Foams | Smooth-On, Inc.
[Edit: Just noticed the stuff is pretty expensive, but it says it expands many times its own size, do idk]

I wouldn't suggest spray foam, or "Great Stuff." I used that at first for the thread mentioned above, and there were no problems with sticking, but as the foam was curing, it seemed to shrink from the inside, which deformed the entire cast after a few days.

Hi Nightride,

yeah i just noticed the price too. That stuff is perfect, but way beyond my budget why is all the cool stuff so expensive lol. drats.

Get some minimally expanding spray foam. AKA Great Stuff or another brand.

Originally Posted by nightrideproductions

Did you consider this:
Rigid and Flexible Castable Foams | Smooth-On, Inc.
[Edit: Just noticed the stuff is pretty expensive, but it says it expands many times its own size, do idk]

I wouldn't suggest spray foam, or "Great Stuff." I used that at first for the thread mentioned above, and there were no problems with sticking, but as the foam was curing, it seemed to shrink from the inside, which deformed the entire cast after a few days.

Did you use enough foam? I figure I use a little more than a half can per skull, havnt seen the shrinking effect problem that you are talking about.

You also got to let them sit for at least a day if not two before you pull the mold.

All in all, I wouldnt rule it out until you try it lonerogue! At $3 a can its worth a shot.

Here is the video I followed with the exception of making a PP mold versus the cut in half skull he does.

YouTube - Cheap Easy skulls

Originally Posted by Bubbels

Did you use enough foam? I figure I use a little more than a half can per skull, havnt seen the shrinking effect problem that you are talking about.

You also got to let them sit for at least a day if not two before you pull the mold.

All in all, I wouldnt rule it out until you try it lonerogue! At $3 a can its worth a shot.

I used about that much foam. I dunno what happened, but it just seemed like it shriveled up. I let it sit for a little more than a day. I might try it again just to see