: Elmoclayman - Viewing Profile

I have been making slip castings of some mugs with Tiki style face carved in them. I made sure to have no undercuts so that they would release from the mold. I had a Cone 10 clay body (Soldate 60, for those familiar with this body) that I was using to make slip from and it seemed to be working just fine. I started using a store bought Cone 06 Clay body that has no grog so I could get a smoother result and also use the brighter colors of the low fire glazes.

My problem is that I am having difficult with the leather hard slip releasing from the mold. The molds are 4 piece molds and made from the same plaster that I was using with the Soldate 60 and having no sticking problem.

Any suggestions would be welcomed.
Brian

Hey all,

I have been making some slip cast mugs and I keep getting bubble that form on the inside of the mugs. After I pour out the slip, when I look on the inside of the mold, I see little voids from what I can assume are bubbles in the slip. They range from about 1/8th inch to 1/4 inch. I can smooth them with a loop tool, but this is pretty time consuming.

I do vibrate the molds with a vibrating sander after the initial pouring for about 30-45 seconds, but after that I just keep the slip topped off until I'm ready to empty the slip out.

Any suggestions on how to get rid of the bubbles?

Thanks,
Brian

Hey all,
I have been using Duncan Envision Glaze - IN-1781 - Pumpkin Orange for a number of years in my high school classroom for a jack-o-lantern project. In years past, it has always come out with a nice glossy pumpkin orange color, until this year. For some reason it has been coming out with a Matte finish and I can't figure out why.

I fire it in an electric kiln, to a temp of 1880-1900F. I also have bisque ware in the kiln as well, but this has not effected the glaze result in the past. The only thing I can think of is that the glaze is "old." It has sat since November of last year, but I mix it very well before being used. Is there a material I can add to increase the glossy result?

Thanks in advance for any suggestions,
Brian

He guys, me again.

I have been making some castings using slip and have been noticing that the inside of the cup is cracking during the drying. It only cracks around the base. Cracks aren't going all the way through, but enough to where they are visible. I was wondering if you may have a suggestion of what might be causing this? Would specific gravity of the slip contribute to this?

Thanks again,
Brian

Hey all, Has anyone used Soldate 60 (From Aardvark clay in Santa Ana, Ca.) as a casting slip?

I am trying to find a good specific gravity to measure to. I read the article by Paul Andrew Wandless and am realizing the 1.85 specific gravity he suggests must be for a different clay slip. The slip I have made from the Soldate 60 has a specific gravity around 1.24. I have tried to add more clay to increase the specific gravity, but with a specific gravity of 1.51, the slip is getting close to the consistency of pudding and I don't believe it will pour very well.

Any suggestions are greatly appreciated
Brian