What Depth Brake Drum?

Hi All,
I'm about to make a brake drum forge and could do with a little advice...
I know that a brake drum isnt ideal (I've read the article at http://www.beautifuliron.com/forge_brakedrum.htm), but all the bits have been found for free & its only going to take a couple of hours to put together. If I'm still keen on smithing in a few months (& when the limitations of the forge exceed the limitations of my (lack of) skill with a hammer, then I'll build a permanent forge to be proud of. Until then...
The brake drum I've obtained is from a truck. The diameter is 17" and it is 10" deep. That seems a bit too deep to me. Not a problem to cut the top off with a plasma torch, but what is the ideal depth? your thought please.
Also...
I've read all I can find on the net about forges and I can see how to build a fire in a 'normal' forge, but I'm not sure how to apply that to a brake drum. I dont mean how to light it, I mean how to 'arrange' the coals & what 'shape' the fire should be.
If you can think back to when you first started (especially if you started with a brake drum) any advice would be welcome.
Many Thanks
Jay

JayBee wrote:
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Okay, don't cut it. Get some refractory concrete and line the drum with a couple inches of castable. (This should be considered an expendable component.) If it doesnt want to stick, then weld on some 'fingers' made of welding rod to the inner surface of the drum for the castable to grip; an inch or so is plenty. This will raise the floor a bit. A deep fire is better than a shallow one, you're not cooking burgers here. The refractory will fold the heat back into the fire, which helps you get the temp up without wasting tons of fuel. If your air comes in at the axle hole, build a teepee of kindling over the air inlet then stack the coal on top. Dribble in a few cc's of diesel and throw in a match and crank the fan. Or you can presoak the kindling in diesel. By the time everything catches, the remains of the kindling will form a loose space over the air inlet and you're cooking.
Hope this helps...
Charly

wrote:
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You have to use deep ones if you want to find a brake drum that's a reasonable diameter.
If you really must cut something, cut a pair of notches opposite each other. This will allow you to lay a long rod through it so that the centre is in the fire. Otherwise there's no problem at all in having a deep dish - you can always put a shallower fire in it.
Personally (having access to welding kit and slightly more money than I had as a kid) I wouldn't bother with brake drums again. I'd go for angle iron and steel thick enough to be rustproof, than a layer of square firebricks. Less trouble than cast iron and cheaper than pourable refactories.
Actually make that _less_ money than I had as a kid 8-( When I was a teenager I had nice cars and never seemed short of beer or petrol.