Source of small glass furnace in UK?

Well, I tried to reply off line, but IE makes it so difficult to get rid of your NO SPAM, I gave up. You will have difficulty finding a way to work that small a quantity, especially if you literally want to melt from a batch recipe rather than cullet. A kilogram (2.2 pounds) is under half a liter volume. You might wish to look at small foundry furnaces or small cone 10 pottery kilns.

The melting technology group of British Glass in Sheffield used to have small gas-fired furnaces that could hold up to four pots, each with about

1kg of batch. They moved recently to the outskirts of Chapeltown. Glass Technology Services now handles that sort of thing. Their web site is and they may be able to point you in the rightdirection.

You might consider building one. It's a lot easier than most people realize - and a LOT cheaper than buying one.

Brady DeBrady Glass/Victorian Art Glass

Build one yourself. My wife and I built a medium size glory hole with a melting pot slung underneath from an old oil drum. Fire up in the morning and start working three hours later. When you ready turn off the gas.

Admittedly our pot holds 7-10 kg, but just take a smaller oil drum :-)

Are you willing to share pictures/plans for that unit?

Pictures on

althoughthe text is in dutch, I'm afraid.Essentially you sling the drums in a frame, isolate themwith 10 cm fire-resistant fiber, pour some dito concreteon the bottom and attach a heavy duty burner blasting througha hole in the side (BENTONE STG-146). It is amazing howstraightforward everything is once you start. Mind you, weexpect from the start that we will have to change the potevery few months. The fiber flakes a bit, but notcatastrophic (yet). We melt glass sherds, and there aremany small bubbles in the glass, as it never gets heatedlong enough to completely get rid of them. The door hangs from a single roller wheel (all-iron bearings!) of the type you often see on sliding barn doors.

I may add that I am a typical white-collar worker, without extensive training in welding and other skills. And as you know, copper wire was invented by a scotchman and a dutchman fighting over a penny, so I think we did not buy anything else new but the burner, the fiber and the concrete. Everything else we scrounged from neighbours or scrapyards.

We also heavily used:

D. Giberson "A Glassblower's Companion", The Joppa Press

H. Halem "Glass Notes, A reference for the glass artist", Franklin mill's press

Both good books, although much information is double. But it is instructive to see two different views on glory hole and furnace building.

Hans,

The pics make it clear enough, thanks. I just wanted to see what you meant by the pot in the bottom. Interesting concept. I helped build a small pot furnace and glory hole last summer but had never heard of the two combined into one.

Neither did we :-)

A few minutes ago we opened the annealing oven for the latest batch, and it is instructive to see how the quality of the glass improves with the time that the pot was heated. The last few pieces (after the furnace had been heated for five or six hours, were of rather good quality, with bubbles so small that they were almost invisible.

The flaking of the fiber causes my wife (who is the artist, I am just the mechanic) some worries. We sprayed it with waterglass before the first firing up of the oven, perhaps should not have done that. Or perhaps it is an inevitable byproduct of the rapid heating and cooling.

That would be a pity, because the pot (although broken) keeps very well.

I would suggest colloidal silica instead of waterglass. We had a thread about that when I built my kiln last year. One trade name is Kaowool Rigidizer, made just for what you're doing. Also, using the pleated process for lining the glory hole reduces loose fiber.

Pot heat time is a definite factor for small bubbles. That is why many small tanks are electric and kept on continuously. That way they have a lag time between charging and blowing. At least this is the way I understand it.

nJb wrote: ...

Is that not just the same stuff by different names?

I don't know that process or I may have difficulties translating it. Can you elaborate on that?

Paai

I thought it was the same stuff but was told in here that it wasn't. I researched it and found that they aren't even close. Waterglass may even be worse than nothing.

A Glassblowers Companion, Pg 32. Dudley calls it the accordion method.

If I remember correctly I received some coaching from Mike Firth and Henry Halem on this issue. Maybe they can jump in here. I also went to several websites of colloidal manufacturers.

The way I understand it:

Waterglass is sodium silicate dissolved in water. Colloidal silica has actual particles of silica suspended in the compound.

When you coat with rigidizer you will also have soft fiber under the hard shell unless you completely saturate the fiber. You don't need to do that.

I'll see if I can find some of the websites I used.

nJb wrote: ...

Oh, yes, we did that. Including the use of our car as power press :-) And the stuff we used as 'waterglass' came from a supplier that also builds industrial furnaces and supplied our fiber. A milky fluid as opposed to the waterglass that my mother used when she treated eggs for keeping.

Can you post the URL here? I must have missed it.

Paai

How colloidal silica is made from sodium silicate:

Other sources list them as being the same thing, still others list them as having differences. Your equipment=your call.