Destruction Test Results

[Eli Jensen]

So I had no intentions of destroying two knives today, rather had every intention of brazing bronze guards on. But I thought I'd share what I learned.

1) The first thing I learned is that I've reached the limit of my TS-8000 propane torch and need an oxy/acet. I could probably modify a fire brick to heat a knife up to 2000F in order to braze the bronze on, but it would take too much time with MAPP and that long at that temp is not good. One blade scaled heavily and steel was burned off, also much grain growth.

2) Water hardens well. Knives were yellow hot, tang was dipped in water, then over 30 seconds knife was slowly put in water a little then out, then a little more. Still hardened like glass. Tried to hammer the guards off but broke the blades instead! Air cool next time.

3) Plating/coating a knife in non-ferrous provides a bit of impact resistance, and more importantly prevents the blade from shattering. It still cracks, but is like windows with that plastic coating.

4) My quest for bronze has been a serious PITA.

[Ray Rogers]

Sounds like you're having fun though. What steel are you using? I think you learned this already but there is a difference between steel getting properly hardened (which includes being tough) and getting hard but still being fragile due to poor grain structure and improper conversion. For any steel I can think of, that slow water dip would likely fall into the latter category ...

[Eli Jensen]

The steel is 1084. Yes I have learned this before. I was not trying to harden it, I was trying to not harden it. I was just surprised that it fully hardened in the area I was brazing. I had always read from critical temp to the quench in less than a second. I thought for sure air cooling for 10 seconds, then SLOWLY in the water that it wouldn't fully harden. Partially maybe, but not like glass.

I am having fun but its also incredibly frustrating. I'm taking the jump into making knives full time, so each setback is a serious discouragement. Especially since I am so close to making this bronze work, I've put so much into it so far.

[Ray Rogers]

That's what I meant about it hardening but not hardening in a good way. It gets hard but the crystalline structure is far from optimal. Anyway, if it was easy somebody would have already done it. If you do succeed you'll have something that makes your knives unique. That can be very important if you're trying to make a living at this game ...

[Eli Jensen]

Thanks for the encouragement Ray. Sure is tough, but definitely worth the reward. I really think an oxy/acet will do the trick.

[Recurve]

Eli, Have you tried silver soldering your guards on? I use silver solder all the time and you can get it to flow at 400.F. Wrap a wet rag around the blade to slow heat transfer and with a little practice your can on an almost seamless joint. Very little clean up required. Just my 2cents -Jim-



www.shullhandforgedknives.com

[Eli Jensen]

I have. I am not a fan. It is a very weak bond, especially compared to mechanical means of holding. Hard silver solder is much stronger than StayBrite, but flows way too high to do after HT and too low to do before. At that point I was only soldering to fill the seam. Otherwise, even on a guard with the most precise slot cut, there is still some gap. Many find this acceptable, and I don't blame them. But I'm not satisfied with that and solder is not the solution. Color is also an important part. Unless I'm using tin/silver fittings, the color will always be off. Also, I like satin finishes oriented horizontally, and it is difficult to do after a solder, much easier vertically. The plans I have with the bronze brazing solves all of this, just need a hotter torch. Will update when I make a new blade to try it out on.