Canister damascus billet cracks when I work it?

[Leon Husock]

The billets come out of the can solid, but once I start working them they develop deep fissures in the sides that I have to grind out before I can keep working. Admittedly I was using a hydraulic press, so was I just working it too aggressively and I should stick more towards light hammer blows? These aren't the deep, "billet isn't solid" kind of cracks I've gotten from some of the pieces where the weld just didn't really get all the way through and you could see the solid bits inside the powder.

 

[Stacy E. Apelt - Bladesmith]

The edges tend to fray a bit in most cases. A few things make it less of a problem:

Number one solution - Use "V" dies to compress the billet.
Weld, then weld again … several times.
Turn the billet as you work it to assure even compression from all sides.
Make sure it is 100% solid before removing the canister.
Make sure it is 100% solid before drawing, or the edges will tear as you squish it out.

Again, some edge tearing is going to happen no matter what.

 

[Leon Husock]

The edges tend to fray a bit in most cases. A few things make it less of a problem:

Number one solution - Use "V" dies to compress the billet.
Weld, then weld again … several times.
Turn the billet as you work it to assure even compression from all sides.
Make sure it is 100% solid before removing the canister.
Make sure it is 100% solid before drawing, or the edges will tear as you squish it out.

Again, some edge tearing is going to happen no matter what.

Thanks, that helps a lot. Unfortunately I don't have any V dies; I was using a friend's hydraulic press, but I set most of my welds by hand. Maybe I'll make some V dies for my guillotine. I just worry that the a 2" can won't weld all the way to the center from hand hammering alone.

 

[kuraki]

The more compression the less this will happen. You can feel when the billet has gone from a mass of powder to a homogeneous billet by how much pressure is required to move it at the same temperature.

Also as DevinT often says, just leave the stupid can on until the knife is forged out. It'll help hold your billet together and just get ground away when finishing.