WarmGlass.com

Hi all.

I remember reading a post on this board about how to apply kiln wash to a glazed ceramic mold (eg a platter or a bowl) and slumping glass into it.

I can't find the post.

Does anyone know how to get the kiln wash to stick well to the glazed ceramic?

I sandblast first then kiln wash, you have to scuff it up.
Bob

I don't have a sandblaster so I use that mesh gritty sandpaper.

I use Universal Mold Coat that Boyce Lundstrum developed. You add acrylic paint to the powder mixture and it lasts through several firings. No need to scuff the surface and it leaves the back of the piece very smooth. I love the product.

Faye posted this previously:

Re: Porcelain Kitchenware for Slumping?
by Faye Malench » Thu Nov 22, 2012 12:22 am
A fast down and dirty method on glazed ceramic surfaces is to coat with spray adhesive, then dust on a layer of dry kiln wash. I use my small glass enamel/powder dispenser to make a smooth layer. The glue burns out but the powder stays in place. Have gotten multiple uses if the mold surface is not disturbed. Can't recommend it for a deep slump or one with detail, as the glass may drag the dry powder as it moves. Great for a shallow shape if you are in a hurry.

Faye, hope you don't mind my re-posting this? Jen

Valerie Adams wrote:I don't have a sandblaster so I use that mesh gritty sandpaper.

Valerie, what is mesh gritty sandpaper? Is it the same thing as course sandpaper?

Peter google 3m drywall sanding mesh.
Way better than sandpaper for sanding shelves.

I've bought a few glazed plates for slumping. They are often cheap, sometimes very cheap and occasionally you can pick up a plate that has a shape unlike anything that is available in slumping moulds or ceramic bisque. The most difficult task is drilling vent holes as the fully baked porcelain is hard. I do not prepare the glazed surface in any way either by roughening the surface or by spraying it with anything. I simply mix the kiln wash with water to a consistency of smooth un-thickened cream and taking a moistened Haik brush loaded with the 'cream' gently brush on one coat with parallel strokes. You can touch it up while it is wet but always in the one direction. Once it dries out any high spots can be lightly sand papered back. You should find the coating very durable so it should last for many slumpings.

If it is a shallow form such as a plate you do not need vent holes.......

[quote="Mike Griffin"]I've bought a few glazed plates for slumping. They are often cheap, sometimes very cheap and occasionally you can pick up a plate that has a shape unlike anything that is available in slumping moulds or ceramic bisque. The most difficult task is drilling vent holes as the fully baked porcelain is hard.

Mike, if you have access to sandblasting equipment you can mask, expose tiny circles and blast. The abrasive will eat through the glaze without the risk of shattering the plate. Jen

Absolutely love Lundstrom's Universal Mold Coat. Works like a dream. Can use glazed $1.50 dishes from Old Time Pottery. No need for holes if the slope is no higher than around 2 inches. This is wonderful, wonderful, wonderful stuff.