SLUMPING.

Handle the problems one step at a time.

Points being .....glass sticking to mold and mold carbon. Use Stainless steel as a mold and Boron Nitride (Google... zyp products) as a mold separator to prevent sticking. If you use carbon steel, you will have the carbon problem.

To use Wood to fire the kiln, you will also need a forced air addition to get the temperature, which will also make the fire wood burn faster, so you will use more fuel(wood) than estimated. In India, coal is regularly used to heat a glass furnace, but forced air is also used to get up to temp. This is theory on my part, never tried to re-invent the wheel, Natural gas always seemed to be there...I used that.

How much time should I allow for the cooling cycle? You will probably not be able to hold the temp in an annealing range so the shotgun method will do the trick, you can't over anneal it, so once you hit fuse temp, and start down, remove the heat source(and insulate it somehow , if that means sand, then pile it on thick to keep the loss of heat to a minimum, let it come down 1 1/2 deg per min on thin pieces that should work. You are going to have to test fire a few so you know what your kiln will do and how it acts.

Reports of actual results would be appreciated.

I have to ask. Is there some reason you believe that the glasses you are attempting to melt together have any chance of staying together? I don't recognize the LcD term, but you mention float. Are the cullet and float compatible?

Not really trying to be a smart ass here but if you're trying to mix random glasses together and heat them by burning oak (if you knew the process of getting enough heat from burning wood, you wouldn't have had to ask that question)and end up with a piece 1 x 1/2 Metre (who knows how thick it is, the most important factor) I don't give you much of a chance. It would be something like me hanging out on a board that discusses space travel hoping to put something into orbit soon.

Keep us posted.

Thanks Jack; thinking about it, tackling a piece that big as a first project does seem rather unwise. I simply don't have any pieces of stainless steel that big either. I do have 50cm square pieces. Stainless steel is a pig to work with.

My other half just suggested that I might avoid the variation in the expansion of the glasses by firing the individual parts separately to keep the jobs small, then wiring or framing it together. She also suggested that I could avoid the melting process altogether by embedding my cullet in acrylic resin. Well, that wouldn't allow the colours to spread like I wanted them to, and it wouldn't be as permanent a job.By the way, I did mention the desired thickness in my post; I've settled on

10mm. I do have access to no end of calor gas; it just struck me that the logs were there and might be a convenient heat source. I wasn't aware of the fact that they aren't quite enough on their own. H'mmm.

Time to stop thinking and do. I'll draw up my moulds for the feature pieces tomorrow (a big 120mm dia orange sun and green and amber leaves mainly) and send for some kilnwash. This sure as hell beats television!

Thanks,

Des.

Can you get shelf paper where you're at? Ceramic blanket? That would solve the sticking problem for sure.

You don't mention what type of cullet you're using. If it's something made for casting you might be in good shape but may have trouble matching it to the float and the other stuff you're using for strips.

Yes you did. My mistake.

Yes, the wood would need an induced draft to attain and control the heat. Where are you? Isn't there an electric kiln you can use. They seem to work best for glass. Efficient and controllable.

You would be happy with the ceramic fiber. If the pieces have flat surfaces you wouldn't even need molds. You can fashion the outside walls from 1/16 or 1/8 inch fiber.

Not if there's NHL hockey on.

Suggested reading:

searchable archives are great. Here's a great tutorial:

Good luck. Keep us posted.