Melbourne Blacksmithing FGT

[doug3030]

Talk us through the process, what and how much forging on the blade, grinding, what tang, how did you fit the handle, heat treating etc.

It started out as a piece of 1084 tool steel bar stock. With the help of a gas forge, a large anvil and a selection of hammers you forge the bar so that one edge takes on a curve similar to what you want the shape of the finished knife to be. Counter-intuitively, the edge that you curve is actually going to be the spine of the knife, not the cutting edge.

Once you have established the curve, you draw out the flat edge, thinning it out and causing the curve you created earlier to straighten out as the previously flat edge takes on the curve you want for the cutting edge. Its important to remember which edge is which when you are halfway through and need to put it back in the forge to reheat. Once you have forged the shape you like, then you do as much smoothing and flattening with smaller hammers as you can to save a lot of grinding later.

The next step was normalizing. This involved heating the blade until it was non-magnetic and swinging it in an arc with the cutting edge facing the air flow until it cooled to magnetic again, repeating that cycle three times.

After that it was profiling, which involved refining the shape of the blade using grinders and files. At this stage the steel had not been hardened and was still able to be worked with a file. The main aim here was to get the outline how you wanted it and to remove excess material from the blade to establish the taper towards the cutting edge, and to remove excess material from the tang. It is a hidden tang knife, so the tang had to be ground down to be a lot narrower than the blade.

Heat treating was next. A special clay which acts as a shield to quenching is stuck along the spine of the knife so that the spine does not turn out as hard as the sharp edge. When this clay is dry the blade goes back into the hot forge until non-magnetic and is then plunged into canola oil. be careful not to plunge the knife in too deep n the oil. The tang must stay out or it may finish up too hard for the it to be drilled to accept the brass pin that affixes the handle. Quenching is a bit of a heart-stopping moment as it is possible for the blade to crack or bend. Mine, fortunately, came out good.

Before tempering can take place the blade needs to be cleaned up with some sandpaper so that the color of the steel will show. The color lets you know how the tempering process has gone. So once the blade has been cleaned up enough with sandpaper it goes in a toaster oven at about 200c (I think) for about an hour and let cool until it can be handled. The steel at this point should show a straw or light purple color. It then goes back in the toaster oven again for another hour and then cools overnight.

Then follows several hours of descaling, shaping and polishing with grinder belts and sandpaper/wet and dry. My knife was sanded to 600 grit for a satin finish. I had the option of polishing it further to a mirror finish, but I thought that if I did that I would be too scared to use it. Once the blade was polished, it was wrapped up in masking tape to protect it through the handle making process.

The handle starts out by making and fitting the brass guard. It was cut from a piece of bar stick and a slot milled in it to accept the tang. This was super-glued on to the tang. I made an ebony spacer to add a little decoration between the guard and the handle. Cutting a mortise into the handle blank to accept the tang was accomplished by drilling a hole down the handle blank and then extending the hole using a ground down jigsaw blade with a file handle attached. At that point I was wishing I had brought a 3/16th chisel with me. Once there is sufficient clearance to fit the tang inside the handle the handle and spacers are glued on with a liberal application of 2-part epoxy. My handle blank was a piece of Beefwood I got from Chris (Mapleman).

Before shaping the handle, you drill straight through the handle and the tang and drive in a brass pin to secure it all together and reinforce the epoxy, not that it should need it but it looks nice. Then it is just a matter of grinding, rasping, filing and sanding any part of the timber that does not look like a handle, giving it a fine sanding and a coat or two of oil.

It then gets sharpened up on grinder belts and polished on a paper wheel. It is sharp enough to dry shave with.

[DSEL74]

Good write up.

Never heard of that type of normalisation process. Didn't you anneal it before filling & grinding? Or just work straight on the normalised steel?

I know of the clay being used in the hardening process but have never tried that method myself. When is was cleaned up could you see a visible Harmon?

Not quenching the tang in the oil sounds like it would leave an abrupt temper line and cause a shear point where the blade can snap under pressure this is usually a no no, and part of the tempering process is to soften it again. But using the clay you already differentially hardened the blade.

I also predrill the pins before hardening.

It's always interesting to hear other methodologies.




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[doug3030]

Never heard of that type of normalisation process. Didn't you anneal it before filling & grinding? Or just work straight on the normalised steel?

Dale, as you know I am no expert on this stuff, but as I understand it there was no need to anneal as it had never been hardened. There may be more to it but thats what I know. We just worked on the normalized steel. How do you normalize?

I know of the clay being used in the hardening process but have never tried that method myself. When is was cleaned up could you see a visible Harmon?

No visible hamon on the blade. The knifemaker showed me a blade where it was visible but that was a different type of steel and had been treated with acid to make the hamon visible.

Not quenching the tang in the oil sounds like it would leave an abrupt temper line and cause a shear point where the blade can snap under pressure this is usually a no no, and part of the tempering process is to soften it again. But using the clay you already differentially hardened the blade.

I probably did not explain that bit well enough. The clay covered the ricasso and part of the tang as well, so there should not be an abrupt temper line.

I also predrill the pins before hardening.

This is a hidden tang knife. Not sure how you could do that on a hidden tang. If you have a method, can you share it?

It's always interesting to hear other methodologies.

definitely

[DSEL74]

Dale, as you know I am no expert on this stuff, but as I understand it there was no need to anneal as it had never been hardened. There may be more to it but thats what I know. We just worked on the normalized steel. How do you normalize?

In very basic terms to normalise is to leave the steel with the properties inherent to the steel. Not hardened or softened. We just leave to the side to cool naturally to ambient temp.

If it has been heated then it has to cool and how it cools will change the properties from its starting point.

Annealing the steel makes it soft.

No visible hamon on the blade. The knifemaker showed me a blade where it was visible but that was a different type of steel and had been treated with acid to make the hamon visible.

Sometimes you can see a faint Harmon and etching brings it out.

This is a hidden tang knife. Not sure how you could do that on a hidden tang. If you have a method, can you share it?

You do a test fit and drill the tang and handle prior to hardening.








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[doug3030]

In very basic terms to normalise is to leave the steel with the properties inherent to the steel. Not hardened or softened. We just leave to the side to cool naturally to ambient temp.

If it has been heated then it has to cool and how it cools will change the properties from its starting point.

Annealing the steel makes it soft.

Ok, then that would explain the tray of cat litter we buried the blades in after normalizing. Fortunately they do not have a cat

[DSEL74]

The kitty litter would be an insulator so you did Anneal it, you just didn't know it.

You may have seen the drum of ash just next to my forge for the same purpose. Throw the hot (nonmagnetic red) item in the ah and completely cover it, then leave it there a day or two to slowly cool, depending on the weather and time of day it goes in and mass of the item it may be cool by next morning. In this case overnight would do a thin knife a hammer head takes a lot longer.

[doug3030]

The kitty litter would be an insulator so you did Anneal it, you just didn't know it.

Dale, as you know I am no expert on this stuff, ...

There - I was right because I was wrong

Learning all the time.

It only sat in the kitty litter for maybe an hour or two tops but it was a bloody cold day where we were.

Cheers

Doug