Date: Sun, 30 Mar 2008 18:25:59 -0500
From: Mike Brose <Mike-AT-puppetsandprops.com>
To: puptcrit-AT-puptcrit.org
Subject: Re: [Puptcrit] Industrial type PVA?


Ed Atkeson wrote:
> ---------------------------
> Mike,
> Would PVA parting film like Partall work with oil clay, plasticine? I  
> use epoxy and fabric over clay a lot, and It would be great if I  
> could coat with something that would let me get the epoxy off without  
> the clay sticking.
> thanks,
> Ed
>
>   
Ed,

Yes, PVA Partall #10 works over the clays I use, which are all 
non-sulfur based. Here's a photo of me spraying some on a model and clay 
parting bed line (half of the model is not visible and is below the 
white support board you see there).....

http://www.puppetsandprops.com/Images/PVAandModel.jpg

I'm stretching my memory here a little, as I've gone to another method, 
which I'll touch on in a moment. Yes, it will act as a barrier, and the 
clay will mostly stick to the PVA and not the epoxy casting. You'll have 
some clean up to do on the clay, but is preferable to scraping clay off 
the casting. Done that many times in the past. NOT fun!! <G>

What I use mostly now for an easier release of clay from epoxy (or 
polyester) castings (or mother molds, when creating a pour-able blanket 
mold) is brushing on a mixture of odorless mineral spirits and vaseline 
in a 5 to1 ratio by weight. Yes, you must use it with good ventilation 
(I use a respirator as well; I'm a bit of a safety nut! <G>). What this 
does is after the mineral spirits evaporates, it leaves a very fine 
layer of vaseline which acts as a release. The clay will pull out of the 
mold or casting much easier and if you haven't missed any spots, will 
not stick anywhere. There will be traces of vaseline to wipe off however.

You will have to decide which would serve your purpose best. I would 
probably do a small test of each process, and see what suits you best.

Hope that helps Ed!

Cheers,

Mike Brose
http://www.puppetsandprops.com

_______________________________________________
List address: puptcrit-AT-puptcrit.org
Admin interface: http://lists.puptcrit.org/mailman/listinfo/puptcrit
Archives: http://www.driftline.org