Re: need advise with Resin SG95 MCP

From: Michael Tsenter (
Date: Wed Oct 23 2002 - 09:11:55 EEST

Dear Andrey:

There could be many causes for your bubbles. Some of these are as

- poor venting of the mold
- incorrect mold orientation that causes trapped air on the upper surface
- moisture present in the resin
- high heat generated by the reaction due to large mass of your part
(solid casting vs. thin wall casting)

The simplest solution would be to use an external pressure tank, and then
pressurize the mold while the resin is still liquid to about 60-80 PSI (4
- 6 Bars). Keep it in the pressure tank until the resin becomes solid,
and then continue the curing cycle in the oven (if required). This step
will compress these bubbles, so that they become invisible.

I am not closely familiar with SG 95 product, but some resins are only
recommended for thin wall castings. You may consider trying a product
from CAMATTINI in Italy ( It is called PROTOCAST
PC2001/G2000. It is water clear and you can use it for wall thicknesses
of up to 100 mm.

Best regards,
Michael Tsenter

NEST Technologies, Inc.
3849 Ridgemoor Drive
Studio City, CA 91604 USA
Tel: 818-761-6500
Fax: 818-761-6116
web site:

Andrey Falaleev wrote:

> Hello List, > I need advise of vakuum castings experts. Help please. > > We have many bubbles on the upper surface of part after vakuum casting > to silikon form. > material: Resin SG 95 MCP; > Part: Transparent cube 50*50*50 mm ; > > Is anybody have this problem too? Is it usually for this type of > details? > Thank you for attention. > Best regards, > Andrey Falaleev > > > BIBA, Bremer Institut für Betriebstechnik und angewandte > Arbeitswissenschafr an der Universität Bremen, > Hochschulring 20, D28359 Bremen

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