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View Full Version : questions about molding and casting.. :)



thelocalmermaid
12-28-2011, 04:10 PM
So... I have a nice scale model that I would like to make a mold of. I'm experimenting with Instamold (for mold) and silicone (for cast) right now with starfish... however, I would like to use a more permanent material (rather than the not permanent Instamold) when I make a mold of my fish scales....

do you have any advice on what kinds of molds make the most lasting/reliable molds?? also, where I can get it? etc. Michaels, online, etc...

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I was thinking that If i used silicone for the mold, and then was trying to to cast with silicone, I would need some type of non-stick agent for silicone so that the cured silicone won't adhere to the uncured silicone.... opinions? does this sound accurate? if so, what type of non-stick agent should I use?

If I use a latex mold, and a silicone cast.. would I still need to get a non-stick agent?


hmmm.. this is all so confusing, I would appreciate any advice..

as you can see, I am trying to create a silicone tail.. which I will do in sections. meaning that, I will purchase silicone in installments and only create what I can afford at any given moment. so this tail will take a long time, but I'm really hoping for something spectacular... at least i'm hoping! :)

your help is greatly appreciated!!

<>< Mermaid Jaimie/thelocalmermaid

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Mermaid Star
12-28-2011, 08:33 PM
For a good permanent mold, I suggest Ultracal-30. You can find it online and at some local clay retailers. I suggest buying local if you can because it is very heavy. I am molding with it and it will take about 80 lbs to cover my scale mold. They come in 50lbs bags.

If you are using silicone for your scale sheet (you are looking at a very expensive mold) then yes, you will need a release agent. Most laces that sell silicone for molding will have the release agent to go with it. Just poke around the site and you should find it or just look up silicone release agent.

You can not use latex with silicone. One inhibits the other and it will never cure. Sorry I am being quick with my reply. I have to wake up in 6 hours for work and I am trying to get to bed. LOL I am doing a great job of it, I know. LOL

Hope that helps a little.

Star

thelocalmermaid
12-29-2011, 01:10 AM
ha! star, you're awesome! I hope by now you are sleeping! thanks so much for the advice. I'll look into the Ultracal-30! you're right. If I use a silicone mold and a silicone cast, it's gonna be crazy expensive!

:D thank you!!

Odette
12-29-2011, 01:20 AM
my sister(works with special effects) prefers using oil-based clay with ultracal-30. hope that helps.

sydthefairebrat
01-21-2013, 02:54 PM
I just found a place in North Hollywood that sells it 100 lbs for $39 + tax. SWEEEET