Tuesday, 1 September 2009

3 Steps to Better Slipcasting

1. Always check the s.g. of your casting slip. keep it at 1.70 at least. That means 100ml of slip should weigh at least 170g

2. Once the s.g. is correct adjust the fluidity with a deflocculant such as Dispex. Even if using sodium silicate for deflocculation I find a few drops of Dispex markedly increase the fluidity giving better casting results

3. If you are using molds that have not been used for some time a fine misting of water on the casting surface will help prevent air bubbles in the cast

7 comments:

Eugene Hon said...

Very helpful information indeed - from a very knowledgeable source. Goof stuff, keep it up.

John Shirley said...

Thanks Eugene for your support. Planning regular posts of how to's and hints and tips

LMR said...

I have a mould I wanted to start using again so these tips couldn't have come at a better time...thanks!

John Shirley said...

If I can offer any other suggestions that could help please let me know

Linda Starr said...

I want to start using a few molds once I get moved, so now I know where to come to refresh my memory of your helpful hints, thanks so much, love your work.

John Shirley said...

Hi Linda, Thanks. Also check out my posts on paperplaster, truly reolutionary!

Linda Starr said...

Hi John, I will check out your other posts. Thanks so much. I took a workshop with Sandra Black and she gave us a paper plaster demo, very enlightening as those molds can get quite heavy otherwise.