[Thyge Thomasen]

I'm in the middle of changing my slip source for casting sanitary wash; temperature 1240 degr. C., (my source went broke!!) I managed to make a good white slip with a lot of chamotte and molochite; just dry enough to avoid huge shrinkage. Then the slip got slim/dry which makes the shape brake through biscuitefire.

I'm then looking for a technique to add fiber to the slip in some amount, enough to make the body less heavy and also stronger for firing.

Can anybody help me with their experience?? Thank you!

Thyge Thomasen

www.thygethomasen.dk

Email me

[neilestrick]

I think I'm not understanding you terminology. Define sanitary wash. What exactly are you making? And what do you mean by dry enough to avoid huge shrinkage? Do you mean the slip is really thick? Are you casting in plaster? If you can give us more info we can probably find a solution.

[Thyge Thomasen]

neilestrick, on 08 March 2013 - 10:29 AM, said:

I think I'm not understanding you terminology. Define sanitary wash. What exactly are you making? And what do you mean by dry enough to avoid huge shrinkage? Do you mean the slip is really thick? Are you casting in plaster? If you can give us more info we can probably find a solution.

[Thyge Thomasen]

The wash bassin is for washroom use. (look www.thygethomasen.dk, menu design). My slip is not fat, and that because of high amount of chamotte and molochite. The slip is ok fluid running. And I'm casting in a double mold of plaster. My problem is that the wash breaks in biscuitfire because of its long shape (75 cm long) and because of its high weight.
Therefore I'm then looking for a technique to add fiber to the slip in some amount, enough to make the body less heavy and also stronger through firing. Do You have any experience with adding any kind of materials; could be fiber from paper or a like, to casting slip?

Hope you got me right this time

[Marcia Selsor]

You could try using some fiber but you'd need to add it carefully. I use a small handful for 190 pounds of dry clay or about 86 kilos.
If you are making your own slip, add the fiber into the water before adding the dry powder. Stir it well in the water before adding anything else.I have mixed my own slip in the past. It takes 10 days to get it ready.
It takes stirring it daily for 10-20 minutes several times. I followed Kenny's directions in the Complete Book of Potterymaking. It was written in the 50s.
I made a slip that was the same as my hand building recipe.

I was casting 22" pieces that were "wings" for amphorae. I got my nylon from Archie Bray Clay Business in Helena , Montana, USA.

Marciia

[Thyge Thomasen]

Marcia Selsor, on 09 March 2013 - 07:04 PM, said:

You could try using some fiber but you'd need to add it carefully. I use a small handful for 190 pounds of dry clay or about 86 kilos.
If you are making your own slip, add the fiber into the water before adding the dry powder. Stir it well in the water before adding anything else.I have mixed my own slip in the past. It takes 10 days to get it ready.
It takes stirring it daily for 10-20 minutes several times. I followed Kenny's directions in the Complete Book of Potterymaking. It was written in the 50s.
I made a slip that was the same as my hand building recipe.

I was casting 22" pieces that were "wings" for amphorae. I got my nylon from Archie Bray Clay Business in Helena , Montana, USA.

Marciia

[Thyge Thomasen]

Thyge Thomasen, on 10 March 2013 - 12:57 PM, said:

Marcia Selsor, on 09 March 2013 - 07:04 PM, said:

You could try using some fiber but you'd need to add it carefully. I use a small handful for 190 pounds of dry clay or about 86 kilos.
If you are making your own slip, add the fiber into the water before adding the dry powder. Stir it well in the water before adding anything else.I have mixed my own slip in the past. It takes 10 days to get it ready.
It takes stirring it daily for 10-20 minutes several times. I followed Kenny's directions in the Complete Book of Potterymaking. It was written in the 50s.
I made a slip that was the same as my hand building recipe.

I was casting 22" pieces that were "wings" for amphorae. I got my nylon from Archie Bray Clay Business in Helena , Montana, USA.

Marciia

Hi Marciia

Thanks a lot for giving me your good suggestions. I will certainly go on with nylonfiber. My concerns are the same as yours, about mixing it correctly. Tomorrow I'll have by mail 1 kg of paperfiber in very fine and small cut. Which I'll try to mix in the wet slip. I guess it will dry out my slip, and make it run slow. Then problems to solve again, but nice. Dit you cast your wings in double casting?
The nylonfiber must be chaseable in Denmark as well.

Thyge