Pottery vs. Glass kilns

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Fusionistic
Posts: 7
Joined: Sun Mar 30, 2003 12:30 pm

Pottery vs. Glass kilns

Post by Fusionistic »

I'm getting in to warm glass work, and have decided to buy a kiln. I was wondering about the difference between kilns intended for glass and kilns intended for pottery.

I am primarily going to be doing glass work, but it would be nice to be able to fire pottery occasionally. (Not to mention it's a lot easier to find a used pottery kiln than a used glass kiln).

From what I've read, it seems the primary thing "wrong" with a pottery kiln is that the elements are typically on the side (intended for firing with multiple shelves) while a glass kiln has the elements on the top (intended for firing a single shelf).

How much of a difference does this make? Can a pottery kiln be used effectively for glass work without too much hassle and learning curve?

Thanks for the info.

Doug Bailey
Lia Howe
Posts: 40
Joined: Tue Mar 18, 2003 1:36 pm
Location: Haliburton, Ontario

Kilns

Post by Lia Howe »

You can use a pottery kiln. There is no reason not too. You will have to do lots of testing to discover hot and cool places. If you are going to large pieces, there is where the problems may occur. If you imagine a piece of glass in a pottery kiln, the glass closest to the sides will be hotter than the middle. This can cause problems. Glass likes to move together. If the sides are "moving" but the middle is "stiff" you can get stress and then breaks. You can use this kiln don't get me wrong. You just have to know your kiln. Even if you buy a glass kiln you are still going to want to do testing. I hope this helps a little.Lia
Ron Bell
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Joined: Wed Mar 12, 2003 12:31 am
Location: Middleburg, Florida

Post by Ron Bell »

Doug - One of my kilns is an Olympic which has side elements only and is fairly deep. I only use it for glass and have had no problems. You do have to slow things down a bit to get a more even temperature distribution, but with a good controller thats easy. The instructor (Judith Conway thanks!) who started me in warm glass made a point of keeping records of fireing schedules and its hard to over emphasize this point. Good luck>
Ron :)
Ron Bell
Black Creek Glass
Clifford Ross
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Joined: Sun Mar 09, 2003 10:08 pm
Location: Myrtle Beach, So. Carolina
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Post by Clifford Ross »

Fusionistic- - - - - you can not fire ceramic in a glass kiln. The temp won't get high enough in a glass kiln for pottery or poured ceramic items. Glass work is mostly performed at 1200 to 1600 degrees. Pottery work goes from 1900 to 2300 degrees mostly. Either buy a dedicated kiln for each, or use a pottery kiln as a lot of us have done that can be used foir both.
Kristalwick
Posts: 13
Joined: Sat Mar 15, 2003 8:21 pm
Location: Denver, Colorado

Post by Kristalwick »

I have 3 ceramic kilns that I use for both glass and ceramics. I love the versatility. I've made really large pieces with double layer glass and 24 inches wide. My suggestions:
Go slow.
You can go much faster when firng ceramics. Be careful with glass. I'm overly cautious but have had great luck so far.

Keep a notebook and thorough records.
I am not the type of person to do this but did it anyway. So glad I did. What happens when you are experimenting with firing schedules. Why this is helpful...perhaps you just opened the kiln lid (by the way, don't open on glass until very cool, I wait until 100 degrees or less), the pieces are quite fused enough so you re-fire but you need to know what temps and times the previous firings were in order to increase the heat or times. So far so good, well, now it is a month later and you want to do the same firing again but can't remember what you did the last time...AAARRRRGGGGGG!
When I finally experimented and acheive the perfect firing, I write it in a table and post it right by the kiln.

Now, after many experiments, I fire 3 shelves of glass at one time (yes it can be done!!!) and I have all the various configurations written down, for example: bottom shelf is filled with projects made of one layer of clear glass, middle shelf is the same, top shelf is projects made up of 2 layers of clear glass. I have a program written out and posted by the kiln for this particular firing.

Over time you will be really pleased you took the time to do this.

Also, try to keep your glass pieces as close to the middle of the kiln as possible. You can have warped shapes if they are to close to the edges. The side that is closer to the edge will get hotter faster than the other side.

Have fun! :D
Fusionistic
Posts: 7
Joined: Sun Mar 30, 2003 12:30 pm

Post by Fusionistic »

Thanks for the information everybody.

It seems that the consensus is that a pottery kiln works for glass, but is fussier.

Given that (at this point in time) this will be more a hobby than a business, I'm going to buy a glass kiln -- since I'm just starting out, I've got a big enough learning curve in front of me without complicating things more than I have to. I have a friend with a couple of pottery kilns, so I'll beg some time there when I need to fire pottery.

Again, thanks for the assistance.
Doug Bailey
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