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View Full Version : What temps are good for fusing/slumping 90 to 104 COE glass?


Helvis
10-23-2006, 08:18 PM
I was thinking about trying some molds in my glass kiln with some scrap and dichroic/moretti/bullseye but I have no idea what temps are needed to thoroughly melt the glass. I was once told that molds were made out of plaster of paris and would like to try to make my own molds. Is that true or am I mistaken? I'd be greatful to any fusers/slumpers who could point me to a good place to find this kind of stuff out. Thanks.

Alan Cross
10-23-2006, 08:22 PM
First of all you can not mix glass at all for fusing it will just break right away.
Also you ca'nt really make moulds out of plaster of paris....you need all special things for making moulds....best to take a beginners fusing couse it will save you a lot of headaches.
Alan :)

Dennis Brady
10-23-2006, 08:50 PM
I was thinking about trying some molds in my glass kiln with some scrap and dichroic/moretti/bullseye but I have no idea what temps are needed to thoroughly melt the glass. I was once told that molds were made out of plaster of paris and would like to try to make my own molds. Is that true or am I mistaken? I'd be greatful to any fusers/slumpers who could point me to a good place to find this kind of stuff out. Thanks.

You can use plaster of paris molds to make molds suitable for slumping, or you can make molds from any of several different materials suitable for such molds.,

I suggest you abandon the idea of melting all your scraps together. As Alan has mentioned, they won't fuse together unless they're matching COE. Moretti will NOT fuse to Bullseye. Whether the dichroic fuses to either will depend entirely on what COE it is.

The temperature required to thoroughly melt glass depends entirely on the kind of glass. Some glass (Gaffer) will be molten at 1400F while other (Boro) requires close to 2000F.

Helvis
10-23-2006, 09:02 PM
I didn't mean that I was going to mix all the glass together, just that I have those kinds and was wondering what temps they would each liquify at. I believe my kiln goes up to 1700 and wanted to make sure I was capable of melting it properly. I do have some boro but I knew that would be out of my range. Thanks for the information though. If anyone has a link to any sites that have more info, I'd appreciate it. Thanks again for your replies so far.

flameonglass
10-23-2006, 09:02 PM
Hi,
Welcome to the wonderful world of warm glass.
Most of us here are flameworkers, not kilnworkers.
The best forum I have found for fusing questions is Brad Walker's
Warm Glass Board (http://www.warmglass.com/phpBB/index.php)
I have gotten a ton of help from them when I had questions.
Good luck!

Helvis
10-23-2006, 09:08 PM
Thanks for the link! I'll check it out tonight!

dclutter64
10-23-2006, 09:51 PM
Here is a schedule I used for making a clock out of scrap glass. This is for 90 coe
600 to 1100 no hold
250 to 1250 10 min. hold
9999 to 1480 15 min hold
flash vent
9999 to 960 hold 20 min
off

This can vary depending on the size of the glass and what you want it to look like when it is done. After the pieces are all fused together, it will need to go back into the kiln for the slumping process. You can slump over stainless steel bowls or canisters, stainless steal pipe (my round jewelry boxes were made that way) or bisque ceramic pieces. You will need to apply kiln wash to any thing you slump over or you can use thin fire paper.
The size and thickness of the glass will determine how fast you heat your kiln.
Slumping
400 to 1000 (f)
9999(as fast as it will go) to 1300 hold until it is slumped the way you like it. You will need to watch it thru the peep hole.
9999 to 950 hold 20 min
off

This is only a go by. It depends on the kiln and the controller you have. You can send me a message if you need more help. Also go to www.bullseye.com . They have some tech sheets there the can help.

By the way you can use plaster of paris, but look on warmglass web for instructions. If you are melting the glass into a mold, the temp will need to go to around 1650.
Debra

Helvis
10-23-2006, 10:11 PM
Thanks Debra! That is very helpful!

goof ball
10-23-2006, 11:34 PM
This link might help get you where you want to go. http://www.slumpys.com/SlumpysStore/firingguide.aspx

Keep in mind, these are only Suggested Firing Temps. Each and EVERY kiln fires a bit different. You will need to tweak your ramping rates/times as well as your temps/times according to your kiln. It's just the nature of the beast.

madnesssr
10-23-2006, 11:39 PM
I second flameonglass' recommendation for the Warm Glass Board. It has a multitude of firing schedules available in the tutorials.