Plastic Model/Hydrocal Mold?

BLAST

Well-Known Member
Hey guys. I have a sculpt that is primarily Styrene, with clay and bondo. I am making Latex/polyfoam casts. I bought a 100 lb bag of Hydrocal to make the mold.

I've now heard that hydrocal molding plastic, doesn't go well, or it might fuse. If I clear coat the entire sculpt enough times, and greased it down with vaseline, can I use Hydrocal to mold it?
 

Great_Bizarro

Sr Member
Anything that absorbs water will have a problem with hydrocal. I don't think it will fuse to plastic, but it might stick. I would try it on a sample first, if it sticks then try it on a sample & treat the sample with silicon spray first to see if it affects the hydrocal. Hydrocal puts off a bit of heat if you have never used it. Also use a clean bowl to mix in if you have some of the prior batch of plaster in the bowl it kicks twice as fast and you can't get it to work right.
 

KingNothing

Well-Known Member
I used hydrocal before. If you vasoline it up it shouldn't stick too much. Be careful though if you're worried of size etc. Also make sure to try and clear coat anyways on your sculpt, so it will be a bit smoother and less touch ups when you are done. Don't forget to spray the mold (possibly the sculpt too) with mold release when you're ready to cast.
 

imaginager

Sr Member
RPF PREMIUM MEMBER
Another thing to keep in mind is the Hydrocal is going to get pretty hot as it kicks...
 

propsculptor

Sr Member
RPF PREMIUM MEMBER
For the castings you should use GI-1000 Silicone, it's what I use without any problems.

From a silicone mold you could make wax castings that could be molded with Hydrocal then the wax melted out, leaving you with a smooth clean mold to do Latex/polyfoam castings with.

The mold you mentioned would probably make not-so-good castings,
but also destroy your original master.
 

BLAST

Well-Known Member
<div class='quotetop'>(propsculptor @ Jun 6 2006, 08:18 AM) [snapback]1257077[/snapback]</div>
For the castings you should use GI-1000 Silicone, it's what I use without any problems.

From a silicone mold you could make wax castings that could be molded with Hydrocal then the wax melted out, leaving you with a smooth clean mold to do Latex/polyfoam castings with.

The mold you mentioned would probably make not-so-good castings,
but also destroy your original master.
[/b]

I like this idea... PM sent.

Thanks guys.
 

propsculptor

Sr Member
RPF PREMIUM MEMBER
PM responded to.

If you want to post the info I gave you, feel free, it's not a secret process :D

The information may be helpful to someone else for a completely different project.
 
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