Need Help With Old Jj Cress Kiln

[Mary S]

I am about as new to using a kiln as anyone could possibly be and I purchased a used JJ Cress kiln from Craigslist. I want to 'slump' bottles with it and have done a lot of research online and am not finding anything that will help. I originally thought it was a Cress Mfg kiln and wrote to them but they said it was a JJ Cress and could not help me. I have only been able to find that JJ Cress is no longer in business.There are no model numbers or anything on it. There are only 3 toggle switches on the front. I had an electrician look at it and he said everything is ok. I plugged it in and each of the three switches controls a few coils beginning at the bottom.

Does anyone know how I would slump bottles in this as far as which switches for how long? I do not want to just throw a bottle in there and guess. I was hoping to find something for dummies like, place the bottle in on kiln paper, turn on switch one for an hour, then switch two. Wait two hours and flick on switch three. I know there is not an exact science and do not expect to get it right the first time, but I need some place to start.

I have attached a couple of photos to this post for reference.

 

Any advice will be greatly appreciated!

Mary

[Callie Beller Diesel]

Lark books publishes a title on warm glass that is pretty helpful in figuring out how to slump glass, and there are other titles out there I'm sure. I'd check the library, or Amazon and read up.

A pottery kiln isn't ideal for glass slumping because of the element arrangements and how fast they can go up, but it can be done. Glass slumping is accomplished at temperatures well below most things ceramic even get moving, and glass involves more phase changes to be aware of.

The best tack might indeed, be to put a bottle in the kiln, go slowly and see how it goes. Check the progress frequently, and anneal properly once it's done.

 

That said, Roberta probably has better info than I do. She does a bunch of bottle slumping.

[Roberta12]

Diesel is right about the changes in phases, ramps etc.  It took me a year to figure out how to slump bottles in my ceramic kiln.  I think every single kiln would have a different schedule. It would depend on the size of the kiln and whether it has computer controls or kiln setter. I have the book that Diesel mentioned, and checked out a lot of books from the library.  You will need an understanding of glass and an understanding of your kiln.  Another good resource is bigceramicstore.com  They have some helpful articles on bottle/glass slumping. 

 

Roberta

[Bob Coyle]

You can slump bottles in the old kiln. The thing is that there is usually a hold at a lower temperature after the the higher slump temperature. You could probably use a witness cone for the top temperature... maybe cone 017 or 018 but judging the lower annealing hold temperature would be a little tricky without a thermocouple. No the other hand, the kiln you have has solid fire brick that cools down slowly and might be slow enought to prevent distortion and cracking.

 

The ideal solution would be to buy (or build) a cheap controller.

 

By the way, the lid of the kiln looks pretty bad. I had an old Cress like that and had problems with the fire brick crumbling onto the molten glaze and sticking.