Saturday, June 27, 2009

Forges and Fire: Part 1

The Firebrick Forges:
I started this forge about 2 months ago with firebricks and refractory cement I purchased from Consolidated Refractories.
It’s basically 2 heavy firebricks with a chamber of light firebricks built around them. I’ve cut down some of the bricks with a hacksaw to give me the chamber space I was after and to provide a ‘doorway’ in the front for the material to pass through.
A hole has been hollowed out of the side with a blunt chisel to allow for a gas torch.
This didn’t work from the beginning and it still doesn’t. One of the issues is that I know very little about forges, let alone building them from scratch. I’ve done some research on this and although the information I’ve found has been very useful, some things are difficult to interpret from words and pictures alone so I think this is going to be another trial and error exercise on my part.
I think the main problem with the forge is the chamber. It’s too big – and it’s square. This means that not only is the little MAPP gas torch (guessing here) not pumping out enough pressure to flood the chamber with heat, it’s also firing directly into the opposite wall, which is… a flat surface – so when the flame hits this wall it just sort of bounces back towards the torch.
I think that if I had made the chamber cylindrical, and a little smaller, the flame would have had an opportunity to swirl towards the front of the chamber and disperse the heat evenly. I’m either going to shape some of the remaining firebricks to put in as inserts to give me the shape I now think the chamber needs, or use refractory lining (kaowool, ceramic fiber) to do the job – but either way; Forge Mark I is going on hold for the time being.

After the failed attempt at the first forge I’ve made a temporary one out of a single firebrick. I got this idea after reading Wayne Goddard’s $50 Knife Shop, and subsequently reading Blade’s Guide to Making Knives where Wayne goes into slightly more detail about the forge.
The forge is basically a hollowed out firebrick with a hole in the side for the gas torch to poke through (similar to the design of my first forge but on a smaller scale) and the firebricks I have access to are smaller than Wayne Goddard’s so it gets really hot because of the narrow chamber - though it doesn’t allow a lot of space for billets. It’s great for annealing and it was big enough to accommodate the Tree Project leaves while I was forging them, but I can’t see it being used for anything much bigger than that.

1 comment:

The Suburban Bushwacker said...

Hey Fella
1. It's arrived! Blog post on the way
2. email Todd at primitive point, he's built several gas forges
3. British Blades has some great stuff about making forges too.

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