TrimTheKing wrote:Thanks for sharing D_W. The forging is something I’ve never had a go at but am very interested in. If you have any more pics or info on how that’s done abs particularly without pro tooling requirements that would be great.
Hi, Mark - in general, it's:
1) get good quality flat stock
2) heat it, but not to high forging heat, and shape the chisel into a taper (if possible, the heats to do this should be descending in terms of peak temperature and the steel allowed to go to black heat before getting into the forge again)
3) grind the forging into a taper (or rather, clean up the forge work and then flatten out the top and bottom so that there are two straight planes meeting at the edge thickness with a little excess to deal with warpage after heat treat).
4) cut the tang part of the back side of the chisel, heat and then hammer the tang into a point
5) install a square of steel by heating that square (with a hole drilled) and pounding the tang into it (through a hole in an anvil). do this several times until it's formed to the tang and goes where you want it to end up.
6) flux and heat the joint for the bolster to bright orange or yellow heat with a brazing torch and then hammer the bolster (which is still a big square). Check for tang straightness as it can get rumpled a little during that, and adjust as necessary before everything is cold (this forge weld can be skipped, the bolster will probably not move much)
7) grind the bolster to rough size on a belt grinder (filing is fine here, too).
8) file the bolster to finish more or less with a safe edge file that's been made safe corner (you get to make the file, but just out of a plain old mill file. The safe edge has to be done, but also the corner, else the corner will still cut into the tang
9) harden and temper the chisel and then finish grind with ceramic belts. This can be done with a typical 4x36 home belt sander (I have only only very slightly better than the home center type here that's direct drive -some unknown brand called "bucktool" they are pretty close to the same price, but it's got more power, a flat platen, the ability to tension a belt and more belt speed).
10) grind the bevels onto the chisel
11) hand finish the metalwork
It sounds like a lot of steps, but it's like anything else - if you have anything else in hand that you like, you know exactly what you're looking for style-wise.
If you don't want to buy special oil, O1 steel is a good choice (and it won't air harden too much on you).
It would be harder to do this without:
1) a good anvil
2) a good belt sander since if you want bevels, they really need to be ground on after the steel is hard. A high speed belt of coarse ceramic (specialty belts that are described as cool grinding) is almost a must - their ability to grind steel without making it too hot to hold is uncanny
3) files - decent files are key
A usable forge is as simple as a paint can with refractory blanket in it and a hole cut in the side for a good sized (bernzomatic TS4000 in the US is a good choice) plumber's torch (use in high heat kills the ignitor, but a striker works fine). A brazing torch is needed for the forge welding, but that's something that can be avoided for a long time.
For more bare bones making of something like this, you can just order bar stock and grind it. Blue spruce doesn't even do that in terms of tapering - it just looks like polished flat stock.
Heat treatment is a matter of evenly heating simple steels (like O1) until a magnet doesn't stick to them and then heat a step further (if the magnet stops sticking at a very dull orange, let the steel get a little brighter orange and then quench it). Once the steel is fully cooled to at least room temp, you can put it in a kitchen oven at 350-400 degrees, depending on how much or little temper you want.
There's no need for a heat treat furnace for steels until you get into alloys like A2 and then on into stainless (they're not a forging steel, anyway - they're just a cut and grind kind of steel - I think they're popular with toolmakers because they're stable and don't warp much, so they end up being cheaper and easier to work with even though the stock is slightly more money).
Aside from lucking into a good anvil, the rest of the stuff can be used elsewhere (I never sand much, but having a slightly better belt sander vs. the tabletop hobby things - one that has a flat platen - is a revelation.
The handles on the "seaton" chest chisel were made on the same 4x36 belt sander and then just cleaned up with a file to get the coarse sanding marks off. I saw knife makers using their belt grinders to make handles in a sheffield video, so it seemed like a good idea, and it works well (aside from managing dust).