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slipcasting molds

updated sun 14 nov 99

 

Andrea & Steve Hogarth on fri 12 nov 99

Hi Everyone,
I am a new member to this list and would like to ask the experts here for
some help. I have sculpted a model of a small clawfoot bath minus the feet.
I have tried making several molds for slipcasting and am having great
diffuculties with removing the cast piece. It is a 3 part mold that is
poured from the base of the tub.
The problems I am having are that as the piece shrinks on the hump side of
the mold it cracks in half. I would take it off the mold earlier if I could
but it won't release.The mold as angled walls and no undercuts. Any ideas???
I'm tearing my hair out!!Thanks
Andrea

John Rodgers on sat 13 nov 99

Andrea, I have been a mold maker for 15 years. I think I know what is happening
but I want to be sure before I launch into a suggested fix. Can yhou e-mail me a
polaroid snapshot of your project.....one of the model, and one of the mold in
an unassembled condition.

Or just give me a call. My number is AC 205-620-4711. An alternate is 664-4796.

I may be able to help.

John Rodgers

Andrea & Steve Hogarth wrote:

> ----------------------------Original message----------------------------
> Hi Everyone,
> I am a new member to this list and would like to ask the experts here for
> some help. I have sculpted a model of a small clawfoot bath minus the feet.
> I have tried making several molds for slipcasting and am having great
> diffuculties with removing the cast piece. It is a 3 part mold that is
> poured from the base of the tub.
> The problems I am having are that as the piece shrinks on the hump side of
> the mold it cracks in half. I would take it off the mold earlier if I could
> but it won't release.The mold as angled walls and no undercuts. Any ideas???
> I'm tearing my hair out!!Thanks
> Andrea

Christopher J. Anton on sat 13 nov 99

I would redo the mold. Since you are slipcasting, a two-piece mold, pouring
from the top of the tub might work better. The tub would then shrink away
from the mold instead of toward it. I am thinking two piece since that
might help in forming the rim of the tub. A single piece mold might be
sufficient.

- Chris

----- Original Message -----
From: Andrea & Steve Hogarth
To:
Sent: Friday, November 12, 1999 10:58 AM
Subject: Slipcasting Molds


> ----------------------------Original message----------------------------
> Hi Everyone,
> I am a new member to this list and would like to ask the experts here for
> some help. I have sculpted a model of a small clawfoot bath minus the
feet.
> I have tried making several molds for slipcasting and am having great
> diffuculties with removing the cast piece. It is a 3 part mold that is
> poured from the base of the tub.
> The problems I am having are that as the piece shrinks on the hump side of
> the mold it cracks in half. I would take it off the mold earlier if I
could
> but it won't release.The mold as angled walls and no undercuts. Any
ideas???
> I'm tearing my hair out!!Thanks
> Andrea
>