Recently I had to make up a batch of a dozen small V-springs. I tried a method I'd read about but never used before, and it appears to be pretty much foolproof. This is probably familiar to many of you guys, but just in case you haven't come across it before, here it is in 10 easy stages;
1. Raw materials. Take a piece of carbon steel - old knife or saw blades work well, also files. Or you can order spring steel stock from Dixie Gun Works.
2. If you're using recycled steel, anneal it first - heat it up to orange with a propane torch or similar heat source, and allow it to cool slowly
3. Having ascertained the dimensions of the spring you want to make, cut the steel to size with a hacksaw, file, grinder &c. If you need to bend it, get it orange hot (as above) first
4. Heat it to orange and quench it in water. At this stage it will be very brittle, so handle like eggs...
5. Dry the spring thoroughly
6. Dry it again.
7. Did I mention drying the spring?
8. In an old ladle, melt enough lead (as pure as possible; lead alloys such as wheel weights or bullet metal have a lower melting point) to cover the spring completely, and drop the spring into the melt. (This is why it's important to get it dry; water and molten lead is a very dangerous combination)
9. When the spring is sufficiently hot that, using a pair of long-nosed pliers, you can lift it out of the molten lead and no lead adheres to it, drop the spring into a half-full jar of engine oil NB the spring should not be hot enough to ignite the oil; likewise, there shouldn't be any droplets of molten lead on the spring to fall into the oil and start WW3; however, just in case you've gotten it wrong, keep your face and hands away from the oil...
10. The oil will bubble and smoke for a while. When it's stopped churning about and is still, remove the spring, wipe off the oil and buff it shiny if so desired. That's it!
Marginal relevance to khukuris; this technique produces a temper equivalent to deep blue (ie in the conventional tempering method, where you judge degree of temper by oxidization colors) and could therefore be used, in theory, for tempering large knife blades such as Bowies.
1. Raw materials. Take a piece of carbon steel - old knife or saw blades work well, also files. Or you can order spring steel stock from Dixie Gun Works.
2. If you're using recycled steel, anneal it first - heat it up to orange with a propane torch or similar heat source, and allow it to cool slowly
3. Having ascertained the dimensions of the spring you want to make, cut the steel to size with a hacksaw, file, grinder &c. If you need to bend it, get it orange hot (as above) first
4. Heat it to orange and quench it in water. At this stage it will be very brittle, so handle like eggs...
5. Dry the spring thoroughly
6. Dry it again.
7. Did I mention drying the spring?
8. In an old ladle, melt enough lead (as pure as possible; lead alloys such as wheel weights or bullet metal have a lower melting point) to cover the spring completely, and drop the spring into the melt. (This is why it's important to get it dry; water and molten lead is a very dangerous combination)
9. When the spring is sufficiently hot that, using a pair of long-nosed pliers, you can lift it out of the molten lead and no lead adheres to it, drop the spring into a half-full jar of engine oil NB the spring should not be hot enough to ignite the oil; likewise, there shouldn't be any droplets of molten lead on the spring to fall into the oil and start WW3; however, just in case you've gotten it wrong, keep your face and hands away from the oil...
10. The oil will bubble and smoke for a while. When it's stopped churning about and is still, remove the spring, wipe off the oil and buff it shiny if so desired. That's it!
Marginal relevance to khukuris; this technique produces a temper equivalent to deep blue (ie in the conventional tempering method, where you judge degree of temper by oxidization colors) and could therefore be used, in theory, for tempering large knife blades such as Bowies.
