Question about molding

Hello guys, in the past few months I made a M77 Paladin/Carnifex from Mass effect and I got up to the molding stage, where things got out of hand. In short I got my test mold silicone cured to itself. I didn't have access to molding wax, as I couldn't find any, or it goes by another name in my country. I tried with PVA release but either I didn't apply it correctly or it is not suited for the job. I have brushable PVA and when applied in a thin film over the silicone and the piece it dried forming drops not as a film. I tried many times still no film coverage on the hydrophobic silicone. Any tips for applying PVA release as I would have the same problems during casting? Also what are acceptable replacements for mold wax? Maybe petroleum jelly? What does the wax contain, as I am more likely to find some by searching the chemistry behind the product? I'll make a WIP thread for the build later on when I get to a PC.

I use Vaseline (Petroleum Jelly) to stop Silicone sticking to itself. Don't use anything water based like PVA.

Telling folks what country you're in will help others advise what you should look for locally.

SAS

Sidewinder said:

I use Vaseline (Petroleum Jelly) to stop Silicone sticking to itself. Don't use anything water based like PVA.

Telling folks what country you're in will help others advise what you should look for locally.

SAS

Click to expand...

I will second that recommendation. Petroleum Jelly works well and is cheap.

MM

Well if Vaseline(Petroleum Jelly) works then all is well. After a more in depth search I found a mold wax Formula Five, being sold somewhere around here i just have to find a retailer that sells it. Thanks for the help both of you. I hope the next pass at molding is alright. Sidewinder- you mentioned not using PVA at all, even when resin casting? Should i use Vaseline again then? For the record I am from Bulgaria
Greetz

To stop silicone sticking to already cured silicone I just brush on the Vaseline straight from the pot, you don't need much, just a thin coat everywhere.

If you are casting resin (hopefully polyurethane if making solid parts) out of RTV silicone molds you do not need a mold release agent (eg wax). You don't need release agent on your master pattern before molding it either, as long as the surface of the master is sealed - with eg. paint or PVA - it should be fine.

Also, don't forget light objects might float in the silicone so stick em to the base of the moldbox!

SAS

Vaseline works fine, you can thin it with baby oil, if needed.

Another plus one for Vaseline as a release agent. Cheap, easy to use and cleans up with warm soapy water when you are done.

Thank you for the detailed explanation. I'll get right to molding!