PDA

View Full Version : Packing kilns/cracking



Glassbackwards
08-18-2005, 03:14 PM
does any one have problems with glass cracking in your kiln when you pack it full and the peices are touching each other?

Mr. Smiley
08-18-2005, 03:23 PM
I don't ever have the pieces touch. I haven't had a problem with breaking glass in a kiln. That should be a safe place... :D

Robert Mickelsen
08-18-2005, 03:36 PM
does any one have problems with glass cracking in your kiln when you pack it full and the peices are touching each other?

If one piece touches another while they are still above the strain point, that contact can result in uneven cooling that could cause a crack. Make sure your pieces do not touch each other. If you have to pack a kiln full, use pieces of fiber blanket to provide a buffer so they don't touch.

Robert Mickelsen

10FennyGlass
08-18-2005, 05:26 PM
i have packed my kiln pull of prodo many times, no room for blankey here. I have also never had a problem. what temp are you anealing? how long? what colors? what kinda work? mothers maiden name?

3 rip min
08-18-2005, 05:29 PM
no one said it cant be done, just that its not a best idea....

Mr. Smiley
08-18-2005, 06:57 PM
I should also mention that I don't do pipes. The pushing of the bowl and blowing of the carb leave some strange stresses in the piece. If not annealed properly, I can see there being problems like this. By annealed properly, I mean a good soak at the right temp and a slow enough ramp... also, them not touching may give you a little more room for error in your program... but I'm sure some pipe guys can chime in and give better advise. :D

steven p selchow
08-18-2005, 08:14 PM
Yeah, I've packed my kiln with solid sculptures over the years, and haven't had a cracked piece, I never fully understood the kiln cycles until well after 15 years of working boro.

My kiln in the 70's was a hot plate with a pot over it, got this cool unit that had a solid round plate, no coils, so it was great for warming birds and flowers for later use, of course I didn't make the stuff I do now, a lot of knitted work, and that stuff tinged and pinged anyway.

steve

The Bigles
08-18-2005, 08:52 PM
If you've got a piece in the kiln that's still got some stress in it (like if you're garaging low, like 975) and you put a piece in right on top of it it might be a little shocked. But, I think a more likely problem would be putting a piece that part of has cooled right into the kiln touching other pieces. It can probably take going right into the kiln but if you touch it to a piece of glass in the kiln it would take that heat at one little point quickly and could just say, "fuck it, I'm gonna relieve this stress right now!"

That being said I stack shit up all the time and never have problems. If I've got a really full kiln I've usually got everything stacked in the back. Then when I finish a piece I set it in front then work on the next one. When the next one is done the previous one gets stacked. I'm not sure if this is what keeps me from having problems or not though. But I might as well keep doing it.

skip
08-18-2005, 11:30 PM
I have had pieces crack from touching each other. Usually when I put a piece i am working on in the kiln to garage and it bumps up to another. It's rare but it has happened to me.

Glassbackwards
08-18-2005, 11:30 PM
The Bigles, Thats a good idea. Ive really never had a lot of problems with this. I just was wanted to know if any one else had or has any ideas on keeping them from cracking. My main concern was adding a hot peice into the kiln and having it roll over to another piece thats been kilning causing some kind of shock...Thanks for all the feed back