Question: mold for fiberglass casting?

[StaggzCosplay]

I have a question to ask from all of you who have done molds before. I am wanting to make a mold of a sculpture i have done of a mask so that i may cast it using a fiberglass and bondo mixture. The problem is, i don't know if the best way to make the mold is with silicone or with plaster. Any help and suggestions would be much appreciated! thanks (oh, and sorry if this is in the incorrect forum)

 

[EyeofSauron]

what material is the sculpt

 

[StaggzCosplay]

The sculpt is made out of oil based clay on a mannequin head.

 

[EyeofSauron]

and you want your final result in resin/fibreglass? then go with silicone. you theoretically can cast resin in a plaster mold, but i wouldnt suggest it. if you do, use lots of mold release.

if you intend to do only one cast, plaster should work, but i would still use silicone+a mothermold for the best results

 

[StaggzCosplay]

Sounds great! Thank you so much for the help! And one final question, do you know where the best place to buy silicone is?

 

[EyeofSauron]

that i dont know as im not from the US therfor never ordering from there but it seems smoothon products are very popular. use the search function of the forum to find out more

 

[StaggzCosplay]

awesome, thank you!