Help with big bubbles

Linda Denli · Post by **Linda Denli** » Wed Aug 27, 2003 3:28 pm

Hello,

I have just joined the forum and am very new to warm glass work and am struggling a bit with technique.

I live in London and the art of kiln-formed glass is not as advanced as it is in the US so I am rather 'on my own' when it comes to problems.

Can anyone help with what seems to be a universal problem and that is bubbles... I have fused a 12 inch circle which I will eventially slump into a shallow plate. It consists of a white opaque base with a blue transparent top and white opaque flowers as a design.

Ufter fusing, quite slowly, it has a large bubble (as well as a few smaller one) which rather spoils the appearance of the piece.

Would it be OK to refuse it in the hope of 'melting' the bubbles away, or is there to stay? Any advice would be most gratefully received

Lisa Allen · Post by **Lisa Allen** » Wed Aug 27, 2003 4:04 pm

If the bubble is between the glass and the shelf, check the level of your shelf with a straight edge. An uneven shelf is the usual culprit in these cases. If it isn't level, you can try to use fiber paper between the glass and shelf to give the air an escape route, flip the shlef ove and see if the other side is better or get another shelf.

If the bubbles are between the layers of glass, you can try slowing down your ramp between 1100ÂºF and 1250ÂºF to 50 degrees per hour. That works for me to avoid the rashy surface that appears when air is trapped between layers. You can also baffle around the piece if you have side elements to keep the edges from sealing before all of the air has escaped.

As far as refiring to eliminate the bubbles, unless you drill the bubble to give it a way to release air and relax back down onto the shelf, you are probably stuck with them.

Hope this helps.

Lisa