Gombabomb
Active Member
Hi. relatively new here... got some sculpting and casting process related questions. This looked like the place to ask since there are some really top-notch sculptors hanging around here from what I've seen. hate being long-winded, but figured i'd ask everything all in one go instead of making a bunch of separate threads.
Started using plastalina to sculpt a few projects with the intent to make molds and casts... not much experience with sculpting. More used to building and carving so it's pretty new to me. Bought a brick of the stuff to use to fill negative space when making molds of props/stuff made with other materials. Never thought to use it to actually sculpt new props/parts until coming here haha. Really new at this if not already obvious.
Did a quickie sculpt of a small vault symbol to cast in resin to see if I liked this process and it turned out pretty well and want to continue using this method for some projects. Not at all impressive and really messy, but exciting to me at least because it was something new and turned out well:
One current project is to finish a psycho mask that'd been shelved since I didn't know how/what to use to make it (was in the "build from found objects" mindset when started) but think I'm going to start from scratch using plastalina over a plastic mask blank. One question about that is after making the mold, what do other people do when pouring the resin? Thought I'd just have a 1-part mold and would be trying to slush cast... but then it would be hard to get an even thickness. So how do I go about making a 2 part mold of a relatively thin object such as a mask? Unfortunately don't have any alganate to mold a life-cast of my ugly face to use haha, but I guess I could use another mask blank... any pointers on trying to do this would be really helpful.
Next question is that I have a splicer mask that i made a few years ago out of acrylic modeling paste that I want to make a silicone mold of... problem is that it is already painted... worried about either the paint being messed up or removed by the process, or bits of silicone getting stuck in the recesses (had this happen with some other items, but they weren't finished pieces so it was okay).
There isn't any sealer or clearcoat on it, just acrylic paint. Would spraying it down with mold release be detrimental to the paint? I want to make a mold but not if it'll ruin the original... also again, would you recommend a 1 or 2 part mold for such a thin mask?
Also have a couple belt buckles sculpted that I want to make molds of, but they're contoured to fit a belt instead of being flat so I'd need a 2 part mold for those too, right?
About painting... did some research and found that smooth-on recommends plastikote sandable primer. Looked around online and a lot of the reviews of the product are in fact from people who use it for hobby purposes and painting resin bits.
According to smooth-on, it should be available at autozone but I checked and they don't carry that product even online. Not at home depot or any other hardware stores either. Anybody know where to get a can of the stuff that isn't online? No problem ordering it, but am really impatient and want to try it out. Like to just walk into a store and walk out with some good quality primer if possible.
Are there any other sandable primers you guys swear by for your resin casts? I know a lot of times it's personal preference, but some different product options would probably point me in a good direction. I'm using smooth-cast... a few different types from the 300/320 range if that makes a difference.
oh. hm. another question that i just remembered... when working with a soft, non-drying clay that can't be sanded... do you try to get as smooth and clean a surface as possible before making a mold? Or do you make a sort of "wip" mold that you use to cast the sculpt in a material that can be carved and sanded like plaster or something similar? Then finish it up and make the master mold from that revised sculpt? Was thinking of doing it that way but it seems like it might be an unnecessary step/use of materials. Is that even a thing that people do? Ended up doing that with the vault symbol badge.. made a plaster mold of the plastalina sculpt, made plaster cast in plaster mold, detailed/sanded plaster cast, made silicone mold, then cast in resin. Okay for small parts, but got to be something more practical for large sculpts.
Thanks for any advice!
-Dreggs
Started using plastalina to sculpt a few projects with the intent to make molds and casts... not much experience with sculpting. More used to building and carving so it's pretty new to me. Bought a brick of the stuff to use to fill negative space when making molds of props/stuff made with other materials. Never thought to use it to actually sculpt new props/parts until coming here haha. Really new at this if not already obvious.
Did a quickie sculpt of a small vault symbol to cast in resin to see if I liked this process and it turned out pretty well and want to continue using this method for some projects. Not at all impressive and really messy, but exciting to me at least because it was something new and turned out well:
One current project is to finish a psycho mask that'd been shelved since I didn't know how/what to use to make it (was in the "build from found objects" mindset when started) but think I'm going to start from scratch using plastalina over a plastic mask blank. One question about that is after making the mold, what do other people do when pouring the resin? Thought I'd just have a 1-part mold and would be trying to slush cast... but then it would be hard to get an even thickness. So how do I go about making a 2 part mold of a relatively thin object such as a mask? Unfortunately don't have any alganate to mold a life-cast of my ugly face to use haha, but I guess I could use another mask blank... any pointers on trying to do this would be really helpful.
Next question is that I have a splicer mask that i made a few years ago out of acrylic modeling paste that I want to make a silicone mold of... problem is that it is already painted... worried about either the paint being messed up or removed by the process, or bits of silicone getting stuck in the recesses (had this happen with some other items, but they weren't finished pieces so it was okay).
There isn't any sealer or clearcoat on it, just acrylic paint. Would spraying it down with mold release be detrimental to the paint? I want to make a mold but not if it'll ruin the original... also again, would you recommend a 1 or 2 part mold for such a thin mask?
Also have a couple belt buckles sculpted that I want to make molds of, but they're contoured to fit a belt instead of being flat so I'd need a 2 part mold for those too, right?
About painting... did some research and found that smooth-on recommends plastikote sandable primer. Looked around online and a lot of the reviews of the product are in fact from people who use it for hobby purposes and painting resin bits.
According to smooth-on, it should be available at autozone but I checked and they don't carry that product even online. Not at home depot or any other hardware stores either. Anybody know where to get a can of the stuff that isn't online? No problem ordering it, but am really impatient and want to try it out. Like to just walk into a store and walk out with some good quality primer if possible.
Are there any other sandable primers you guys swear by for your resin casts? I know a lot of times it's personal preference, but some different product options would probably point me in a good direction. I'm using smooth-cast... a few different types from the 300/320 range if that makes a difference.
oh. hm. another question that i just remembered... when working with a soft, non-drying clay that can't be sanded... do you try to get as smooth and clean a surface as possible before making a mold? Or do you make a sort of "wip" mold that you use to cast the sculpt in a material that can be carved and sanded like plaster or something similar? Then finish it up and make the master mold from that revised sculpt? Was thinking of doing it that way but it seems like it might be an unnecessary step/use of materials. Is that even a thing that people do? Ended up doing that with the vault symbol badge.. made a plaster mold of the plastalina sculpt, made plaster cast in plaster mold, detailed/sanded plaster cast, made silicone mold, then cast in resin. Okay for small parts, but got to be something more practical for large sculpts.
Thanks for any advice!
-Dreggs
