Forge and Fire: Part 2

Planning the New Forge:
Ever since I started thinking about forging knives I decided that I wanted to build my own forge. This was for two reasons – 1: Because I’m going to appreciate something more if I’ve built it myself, and 2: Forges are EXPENSIVE! I think the cheapest I’ve seen was around $400 for a little farrier’s forge.

I know that I’ve already got an unfinished forge sitting neglected on a shelf but what I’ve had in mind from the very beginning is a forge built out of a propane/compressor tank (similar to the ones here and here). I’ve found a good number of resources online and settled on the design I want to use, and earmarked an air tank off a truck that I picked up at a garage sale for $15


Next, I’ll need to buy ceramic fiber for the lining and something to coat it with (Fiber Coat/Service Coat) so it doesn’t end up killing me (it’s carcinogenic and when left uncoated can shed small fibers).

The forge will also need a burner (or burners) to deliver the gas. I’ve found instructions for building a venturi burner on the Tharwa Valley Forge website and it looks relatively doable.

Finished Leaves

They're done. It wasn't as difficult as I originally invisioned - though I've still got a long way to go and I'm pretty sure making a knife this way is going to be a lot harder than stock removal. I'm happy with the way the turned out though - and hopefully so will be the ABA.

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.

Copper Leaves

I fired up the forge yesterday and heated the copper rod I picked up at the scrapyard and this is what I've come up with so far after a bit of persuasion with a hammer. It still needs a little refining but it's getting there.