Kiln Schedule for Firing Glassware Paint
This may seem silly but I’d really like to paint glassware for my home. I do have a kiln that I haven’t used for quite a while. I’d like to know where to find supplies and if there is anything special I need to do to prep my kiln. It does have a cone shutoff. In addition, I’d like to know if I need to use any special type of glassware or how to make sure it won’t blow up in the kiln.by Marilyn Tennant
Good question Marilyn. As I’m not experienced in using the paint that you have to fire on wine glasses, I asked Mark Angus (one of the UKs foremost glass artists, no less!) for some help with the answer. He very helpfully mailed me the following. I’ve attached two of his pieces – one finished and one in progress, so you can see his work. Just click on thumbs to change the image:
Mark Angus’s reply:
Any glass ware can be painted and fired in a kiln. From expensive drinking glasses to cheap imported vases, to jam jars and beer bottles!! However, when buying a suitable glass, say a vase, look at the wall thickness of the glass, and the thickness at the base. If there is a big difference in glass thickness then you would need to make the firing schedule ramp up and down slower. Also if the glass is flashed, ie with two colours, (typically these might be an opal white on a clear) then similarly extend the kiln firing time as there may well be tension in the glass.
For normal glass paint I fire at 550 C and soak the kiln for 10 minutes. I would fire up at 100 degrees per hour till 100 degrees, and then at 200 degrees per hour to 550 degrees. Cooling down I do not control, relying on the kiln to be slow enough. Do not open the kiln vent or the kiln when cooling.
However for thick glass and variations in thickness and also for flashed glass vases the firing schedule would be a bit different. I would go at 100 degrees per hour for the whole heating and I would control the cooling between 500 and 400 degrees to say 3 hours, maybe longer if the vase was bigger.
If you want to paint wine glasses be careful that it does not bend at the high temperature point. It may be difficult to fire a wine glass with a long thin neck. Test one on a quicker firing and see!!! Maybe omit the soak time, but if the bowl is heavy and on a thin neck it probably will bend over in the firing!! You can fire it upside down, but have the rim lifted onto off cuts of kiln paper to allow the air in and out.
I use normal glass paint – transparent colours and black. I use one firing, painting the black first with oil, and then the colour second with water. If you need more explanation of this then go to Milly’s page which gives a series of free tutorials on how to paint glass here.
Allow a little space around and above the wine glass, – ie do not have a vase that is nearly touching the top or sides of the kiln. About 3 inches clearance is necessary.
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