Charcoal barbecue for heating metal

[ivan]

Fine WW* featured a home made hearth some years back in its black and white days. Used water barrel to make a twyere topped by a multi holed piece of ms plate. I think the furnace was made in a dustbin lid, with air entering from centre/below, the lid lined with refractory, holey plate level with refractory surface. I think coke was used, quite a deep pile so the holey plate was thus below the hottest area so it didn't burn out too quickly. Lid was supported on an angle iron frame, and the water barrel was connected to a vacuum clener on "blow", regulated by un/covering a hole near the vac. Was used to forge carving tools or similar.

* reprinted in "FWW on Hand Tools"?

 

[chuckey]

Try using "Celcon" blocks, lightweight aeriated concrete blocks, available from any builders merchants. They can be cut with an old saw or a line of holes drilled in them and then cut. They do degrade but are 1/10 the price of proper refractory bricks.
As a teaching your Granny to suck eggs comment, keep all these materials dry or the trapped steam may cause them to explode.
Frank

 

[Wildman]

The point is the bricks are fireproof and will not explode as cement does. They are proper engineering brick.

 

[Dee J]

For a one-off just about any simple setup that forces air through burning charcoal will work. If it's in a metal container then don't use anything galvanised - burning zinc fumes are a known hazard. If you want a lining then mud is as good as anything. In fact the simplest forge setup is a hole in the ground. Just use some steel or copper pipe to introduce air near the base of the fire. Lots of blower systems - from feed-sack bellows to hair-dryers and hot air guns. Some control over the air intake is vital, if you haven't got speed control then some sort of diverter would probably do.

 

[JohnPW]

To answer my own question, it seems you can just hold a hair dryer over the charcoal, eg this vid at about 6 minutes:

https://www.youtube.com/watch?v=zULRWT5eLgM

But having the air enter from underneath works better, eg

https://www.youtube.com/watch?v=YR2bxN9nJ20