Lflank
Well-Known Member
As some of us know, I've recently ventured to dip my toe into the ocean of casting, and made some casts of a pred laser mine thingie using the beginner's kit from Smooth-On (I also did a test cast using a mold I made from Home Depot silicone too, which also turned out pretty good).
So now I'm ready to move to the next level of difficulty--casting an object that has two sides to it, instead of being flat on one side. What I'm thinking of doing is making a somewhat larger and more detailed version of my custom smart disk out of clay (which will force me to improve my currently-rudimentary sculpting skills), then casting it in resin. Since the only materials I know how to use are Smooth-On Oomoo 30 and Smooth-Cast 300, that's what I'm planning on using.
My dumb newbie question is how to physically cast both sides. It was easy enough with the flat-sided object--I just placed the object flat side down and then poured the Oomoo over it as thick as I needed it to be. But how do I do that with a two-sided object? I assume I need to somehow place the object in a casting box, make some sort of clay dam or something to cover the bottom half, then pour casting rubber onto the top half, let it dry, then flip it over and pour rubber on the other side. So my first question is: if I let the casting rubber on one side dry completely and then cast the other side, will the sealer and releaser prevent the new layer of casting rubber from sticking to the old one, so I end up with a two-part mold? I'm assuming so, but would rather ask and be sure.
The other thing I'm having trouble conceptualizing is how then to pour the resin into the finished mold. Somehow or another I'll need some sort of hole to the outside so I can pour the resin inside the mold. Can I assume that this will leave a little tube of resin in the finished cast which I would then have to remove (unless I can integrate the little tube into the design of the object itself)? I get that when casting a mask, you just pour the latex into the big hole at the bottom--but what happens when the object one is casting doesn't have any such hole?
Forgive me if this question sounds dumb, but this is all new to me.
So now I'm ready to move to the next level of difficulty--casting an object that has two sides to it, instead of being flat on one side. What I'm thinking of doing is making a somewhat larger and more detailed version of my custom smart disk out of clay (which will force me to improve my currently-rudimentary sculpting skills), then casting it in resin. Since the only materials I know how to use are Smooth-On Oomoo 30 and Smooth-Cast 300, that's what I'm planning on using.
My dumb newbie question is how to physically cast both sides. It was easy enough with the flat-sided object--I just placed the object flat side down and then poured the Oomoo over it as thick as I needed it to be. But how do I do that with a two-sided object? I assume I need to somehow place the object in a casting box, make some sort of clay dam or something to cover the bottom half, then pour casting rubber onto the top half, let it dry, then flip it over and pour rubber on the other side. So my first question is: if I let the casting rubber on one side dry completely and then cast the other side, will the sealer and releaser prevent the new layer of casting rubber from sticking to the old one, so I end up with a two-part mold? I'm assuming so, but would rather ask and be sure.
The other thing I'm having trouble conceptualizing is how then to pour the resin into the finished mold. Somehow or another I'll need some sort of hole to the outside so I can pour the resin inside the mold. Can I assume that this will leave a little tube of resin in the finished cast which I would then have to remove (unless I can integrate the little tube into the design of the object itself)? I get that when casting a mask, you just pour the latex into the big hole at the bottom--but what happens when the object one is casting doesn't have any such hole?
Forgive me if this question sounds dumb, but this is all new to me.
