Pot Melt

[Sherry R]

I finally got up the courage to try a pot melt. My firing schedule worked out good and the glass melted and annealed as it should, but I used 1/8" fiber paper to melt the glass on and blocked all four sides with kaiser board. The bottom of the glass is really, really rough -I read a lot of tutorials where fiber was used, so I thought that would work. I thought about using a clay saucer but when I kiln washed it, it seemed to slide off the saucer and flaked when it dried. I've read horror stories where some people used a kiln washed kiln shelf but it pitted and some of the glass stuck on the shelf. I use 96 Coe and I fired to 1650 degrees. I didn't want to have glass explod in my kiln so I only fired to 1650 and not the 1700 that some fire to. I didn't want to ruin my kiln shelf because of the high heat. What would you all suggest for my next try.

[bob proulx]

I just use kiln wash on my shelf, sandblast and then fire polish.
Bob

[Laurie Spray]

If you do not have a sandblaster try melting onto a clear glass piece. We use a stainless steel ring for the form with 1/8 fiber paper (not shelf paper) in the inside of the ring and then put a clear blank that easily drops into the ring....not disturbing the fiber paper. Without using a clear glass blank we make sure to have a freshly kiln washed shelf...3-4 coats -(we use Bullseye) then any kiln wash that does adhere to the back of the melt comes off easy enough with a diamond hand pad.
another thing is to put clear glass scrap (clean!) into you form and melt onto it. Great way to use scrap and makes a nice surface.

[GetGlassy]

I've put down a piece of clear in my dam on a kiln washed shelf.

[Sherry R]

Using a sheet of clear glass is a wonderful idea. Put the clear glass on the kiln washed shelf and let the pot melt drop onto the clear glass and dam if I need to - is that correct?

[GetGlassy]

That is how I do it Sherry. It adds depth to the pot melt too. I dam mine mainly to keep it contained.

[Stephen Richard]

.......... I didn't want to have glass explod in my kiln so I only fired to 1650 and not the 1700 that some fire to. I didn't want to ruin my kiln shelf because of the high heat. What would you all suggest for my next try.

Thermal shocking the glass is not possible after about 580C, as the glass is already plastic. Look at the Bullseye tech note on heat and glass.

The kiln shelves are normally rated to a higher temperature that our glass kilns can reach. If you are using a ceramics kiln, then you can affect the shelves by the high temperatures achievable in them. You are more likely to break your shelf by having large moulds directly on the shelf shading the heat in only on part of the shelf, so it breaks from the temperature differential. Also rapid rises in temperature on large shelves can break them at relatively low temperatures due to the way the ceramic expands.

[ejgiebel]

I've done the clear piece on shelf paper on a kiln washed shelf, but you want to make the clear piece as big as the dam you are using. And you want a solid piece of glass, no seams (or, at least the one time I "pieced" the clear, the result was, well, it's on a shelf somewhere in my workshop). I've even used a piece of clear thin.

To be honest, I likely read the idea here, but didn't really believe it until I tried it. Just had the feeling the clear would pull in before the melt started flowing, but that didn't happen.

Ed