Building The Forge Body
The forge body is the main component, holding the parts and housing the insulator. If you have access to a welder, it's simple to design and build the body to your exact needs, but many of us use reclaimed materials, usually a tank of some kind. Old propane tanks are a popular choice.
As you know from last week's article, I used an old fire extinguisher tank that I picked up a few months ago at an antique store. It's compact, with a handle at the bottom and a tight mouth at the top.
I started by cutting off both ends just below the weld seams using an angle grinder, and bolted on hinges to "reattach". This way I had two doors for the forge. On the one end I would have the original mouth of the tank, and this could open up further in case I had larger projects to work on such as axes or hammers.
The opposite side could open as well, in case I needed to work longer projects, and would keep it closed otherwise to conserve as much heat as possible.
The bolts will later be covered with insulating blanket and refractory
A small side note: make sure you mark out properly which side is up, down, and exactly where the hinges should be. Of highest importance is to make sure you don't have everything lopsided or unbalanced, but also double check you have the hinges on the correct side. Because I am right handed, I have the hinge on my left when I'm facing the mouth of the forge.
Next is the base plate. Because the body is circular, I bolted a flat plate of steel to the bottom.
I like to keep my forge on top of a few cinderblocks, held up by a cart. I don't like to keep it permanently fixed anywhere, as I'm constantly moving and rearranging things in the workshop. Because of this, I used long bolts and kept them extended: the forge is placed on top of the cinderblocks and bolts go in the opening, this ensures that the forge is not bumped off its stand.
The final step in the forge body is setting up the torch.
Now there are two things I did not do in this particular rendition that I intend to do in the future; first, is build proper angling for the torch.
For peak efficiency, the torch is best built at a slight tangent to the wall of the forge, rather than directly down. An angled torch will shoot the flame along the wall of the forge, creating a swirling flame. This mixes, spreads, and contains the heat for as long as possible.
I intend to modify the torch better in the future but for now, this runs efficiently enough for me not to have any problems, especially as I don't do very long of workpieces.
Second is the method of fixture. I punched a hole through the forge roof, slid in the flare, and pinched down the edges of the punched hole to fix it in place. Obviously welding, or a better mechanical fixture is superior, but I was in a rush to get this going for certain projects and this is extremely sturdy for now, and will require only simple modification for a more firm structure in the future. Later insulation and clay structuring cemented it further, but that'll be a topic for next week.
You can see the top is threaded; the torch shaft will later screw into this component.
The flare protrudes a bit into the forge, which had me a little worried that it would stick too far into the interior and overheat (disintegrating over time) but later when I installed the insulation it ended up being perfect distance.
A possibly superior way would be to cut the hole into the body and place the flare on top rather than inserted into it. Inserted as it is now puts the tip of the flare nearly into the forge interior, which means it gets red hot and at higher temperatures will disintigrate faster. This means I'll have to replace the flare months down the road but this isn't much of a worry, especially as once the insulation is installed it will be flush with the walls of the forge.
So that's the forge body setup!
I think this is the seventh forge I've build, possible eighth.
Definitely more compact, tight, and efficient than any other rendition to date.
If you have built your own forge and have photos of the setup, I would love to see what you made it out of and how it was done! There are always ways to improve.
Next week will be the insulation, and following that an overview of the torch build (spoiler: it's a Ron Reil style burner).