Advice needed on casting this Palpatine prosthetic

[thedarkone]

Hello all, im in need of some assistance on the best way to go about molding this palpatine prosthetic im finishing sculpt work on. Im gonna cast it out of dragonskin fx pro silicone with slacker to make the brow and cheek fleshy to the touch. For the most part know how a prosthetic is cast but my worry is if im gonna make the negative mold out of resin will the severe undercuts prevent the postive from demolding or would it be better to cast this in a two or three part mold? im initially going to cast it with silicone so i can make a resin master so a simple one piece will be fine on the clay as i can just tear off the clay and clean the negative. Its if i ever want to make another mold off the resin master that worries me. Hope this isn't too confusing. Here a pics of the sculpt so far.

Cheers,
Andy

 

[John Hart]

I would suggest a flexible urethane case mold with a 2 piece rigid backing.

 

[Ozymandius]

It took me a couple of read-throughs, but I think I finally figured out what it is you want to do.


1. You definitely need a hard mold to cast a silicone prosthetic. You have to clamp your mold and headform together to squeeze out the excess silicone, and a rubber mold would deform under the pressure, even with a mother mold backing it.

2. Resin is not a good mold-making material. It's too prone to bubble if there is any moisture AT ALL.

3. If you really think you need a hard master (I have no idea why, but it's your project...) then you could just pour up a denser silicone cast without the Slacker, remold it in silicone and use that to pour a hard master. Shrinkage is your obvious problem there, so it would be far easier and less costly just to resculpt it.

Oz

 

[piehead]

I have made countless prosthetic pieces using silicone. personaly i would mould it in fastcast something like easyflo 120 is good. i understand the moisture issue noted above but this should realy not be an issue with this. just seal the sculpt, add a coat or 2 of spray wax then lightly talc it and away you go. do a surface detail coat of resin , then back it with a thickened resin polybires are great for this. here in the u.k. we mainly use fibreglass and resins for these sorts of prosthetics as the quality of our stones are really bad. also some of the best prosthetic edges are made from a silicone mould with a resin or fibreglass jacket. Neill Gortons art of silicone prothetics range of dvd's are fantastic for learning this work.

 

[Ralis]

Undercuts, yes undercuts its looks like you may have some at the corners of the jaw, watch out for those! If you have undercuts and do a one piece rigid negative mold your positive will be locked in. You may want to do a two piece fiberglass mold and just run the seam down the middle. or you can do a one piece platinum silicone mold and a two piece mother mold made from fiberglass. You can cast a platinum silicone in a platinum silicone with proper release "vaseline"

 

[TimSnowman]

I personally would make a plaster mold. It wouldn't have to be that big seeing as it's just a partial prosthetic. As far as undercuts go, if you're casting in silicone, it doesn't really matter. It'll have enough flex to come out. I like plaster, because you generally don't have to worry about bubbles or any cure inhibition issues. And there's the whole "not carcinogenic" thing, lol. I also think plaster can capture more detail than resin. Ultimately it's your project and everyone on this thread has given great advice, so it's up to you. I look forward to seeing what you decide. Good luck.