Glass Information and Education

Flat (full) Fuse:

Remember this is for a reasonably sized piece. If you are fusing an elephant, the program will differ considerably!

Place object(s) in kiln. You want to raise the temperature slowly so not to crack you glass ergo:

Go up to 1000 degrees F in 2 hours.

Take another hour to raise the kiln temperature to 1450 degrees.

Stay at 1450 for 45 minutes (this is called soaking).

Then you want to drop the temperature as quickly as possible to avoid devitrification (ugly crystals that forms on the surface of your glass) so if you have a computer controlled kiln you would set it to go to 980 degrees in 1 minute. It can’t of course, but in trying you go down to 980 as quickly as possible.

If you don’t have a controller on your kiln, just crack it about an inch until it goes down to about 1020 and then close the kiln.

Soak therefore a half hour.

From then on it is just a game of gradual cooling.

Go to 875 (this can be as quickly as you want, at that temp 100 degrees should not make your glass crack BUT, at each step you have to give the glass time to adjust. Sp

Soak at 875 for a half hour

Go to 775

Soak for a half hour

Do you see a pattern here? Actually, you can just turn the kiln off after the 775 soak. It should achieve room temperature gradually enough on its own then.