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TJR

Cottle Boards

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O.K.; I built my cottle boards and I am ready to start making some press molds and some slip cast molds.

Two questions;

1. Should I seal the molds first with marine varnish, or paint?

2.Is there another material, other than mold soap, that is less expensive and works just as well? I can't see repeatedly going to the ceramic supply store just for a bottle of mold soap.

TJR.:blink:src="http://ceramicartsdaily.org/community/public/style_emoticons/default/blink.gif">

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I put shelf/contact paper on mine. Plaster doesn't stick to it and it's easy to replace when it wears out. Liquid hand soap, thinned a bit with water, works fine. Just don't make bubbles or it will show in the mold. Some people like Murphy's Oil Soap, but I think it's harder to clean off the mold.

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I roll out slabs of modeling clay (the cheap stuff), line the boards and bottom, smooth the joins to seal, pour plaster. They can be reused several times before having to re roll. No leaks, no mess, no soap.

 

If I need it really smooth, I use a piece of glass on the bottom with a thin coat of Murphy's oil soap diluted half with water, or hand soap like Neil said.

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Thanks gents for your rapid response. I made a New Year's resolution to not throw for a while. I am trying to make a technical junp here with my work. I have used plaster molds, and even made them, but it was 1982. You can't expect me to remember all these small details after 30 years. I'll let you know how it goes.

Tom.[TJR].

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I clay up the all seams with junk clay(to fill the cracks) and then spray with mild soap solution in spray bottle just before mixing plaster.

Knock it all down with the plaster is warm.

Mark

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I use urethane varnish on mine. I also use WD-40 for release agent . I have 8

pairs of various sizes to accommodate different needed sizes.

 

Marcia

 

 

Marcia;

I realize that I am going to have to make a smaller set. Mine are 2 ft for two boards and 3 ft for the other two. Good for a plaster bat for drying clay, but too big for individual pieces.

TJR

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I soap with Jergen's Pure and Natural bar soap applied with a 2" bristle brush. I apply many coats letting the soaped surface dry between applications.

 

I clean the mold with Dawn dishwashing liquid and hot water scrubbing with a Scotchbrite making sure I don't mar the working surface of the mold.

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I use urethane varnish on mine. I also use WD-40 for release agent . I have 8

pairs of various sizes to accommodate different needed sizes.

 

Marcia

 

 

Marcia;

I realize that I am going to have to make a smaller set. Mine are 2 ft for two boards and 3 ft for the other two. Good for a plaster bat for drying clay, but too big for individual pieces.

TJR

 

For my wedging table I poured it directly into a table frame on 4 x 4 legs. It is just my height. (short) I didn't use cottle boards for my large plaster drying slabs. I just used boards nailed and/or strapped together. My cottle sets range from 12" to 20" and in between.

Marcia

 

 

Marcia

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I use the largest cheapest can of spray cooking oil (dollar stores). Is that a bad idea? I'm new to this, and that was a piece of advice I got. I recently made the texture boards I read about on this site, and the cooking oil seemed to work ok. Will it effect my glaze?

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I use the largest cheapest can of spray cooking oil (dollar stores). Is that a bad idea? I'm new to this, and that was a piece of advice I got. I recently made the texture boards I read about on this site, and the cooking oil seemed to work ok. Will it effect my glaze?

 

 

I don't like using oil as a release agent. It works well, but I think it's much harder to clean off the mold. If you don't get it cleaned off well, the plaster won't be as absorbent as it could be. Soaps wash off very easily.

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