Death of a Bowie

[SVanderkolff]

Let me tell you a sad tale of lost opportunity and wasted time.

I was given, by a good friend of mine, a bowie blank of random damascus. This was many moons ago and the blank sat and looked at me waiting for inspiration to strike. Many times the blank tried to show me what it wanted to be but never could make it's wishes clear. Finally, in a blinding flash of light, it came to me, communication had been established. A coffin handle, bolsters not guards, deep hollow grind, slightly upswept false edge. dead flat ricasso and face. Out came the sketch pads, the pencils and erasers, out came the scribes, the center punches and the counter bores. The KMG was warmed and ready, new belts, good tunes, steady hands. Let the grinding begin. And low it was a wonder to behold, every grind was perfect (well almost) every flat was exact. Both sides were as twins to the other. Polished to 600 grit and ready for the oven. Quench oil standing by warmed and waiting as the blade reached critical temp. The magic 1750 was reached and held. The moment of truth, open the kiln pull out 14 inches of glowing steel , quick dip into the oil but hold something is just not right. Wait for it, let the blade get down to a reasonable temperature.

Heartache...... the edge of the blade looks like a bad sea scape , waves, ripples, out of line by almost 1/2" from center ...... beyond hope.

Steve

[Mark Williams]

So what did it do, delaminate? or just warp. 1750 or 1450?

[Ray Rogers]

Yeah, 1750 sounds too high. Aside from that, I've done that same thing. That's the reason I now do all my grinding after heat treat. No more warped edges and, if there is any pitting or surface decarb, that gets ground away ...............

[Rocket_Jason]

Hi Ray-

I was taught to do 90% of my grinding before heat treating. The reason is that grinding may ruin the HT process due too much heat build up. Is that not true, or are you just really careful not to build up heat?

-Jason

[striper28]

1750 was too hot for a random pattern damascus blade, should have been around 1500 like O-1. The other thing is that if you can get the knife hot enough to change the temper while grinding then you are going to burn your hands. If you temper at 400 deg and the blade is a straw color, do you see that color while grinding? 100 deg would even burn your hands. If you grind carefully and dip in cool water after every other pass then you should be fine.

[Fox Creek]

My sympathies. I have been working on a thin 1095 blade that went all wonky when I quenched it. I hadnt worked with 1095 for quite a while and had forgotten how relatively unforgiving it was, tending to foreg cracks and cold shuts, compared to 1084. The fire was getting balky too which didnt help. And I hit the hot oil with it slantways on the flat the first time in. I think that I was working from too high a temperature also. BUT, I normalized and straightened it out and rehardened it, from a lower heat. And I did get it hardened sucessfully. Just heat it back up to a forging heat s l o w l y and gently reforge it. It will be a different blade, and you will have to do another finish grind, but there is a knife in there that wants to come out!

[RogerP]

Heartache is right - that is a real bummer.

Roger

[cactusforge]

When I first started forging knives I was plagued with blades warping. I read in The Complete Bladesmith that if you forged to shape and then did the heat treating it would stop the warping so I tried it and no more warping. I grind all my forgings in the hard state and it is no problem to not damage the heat treat. I hollow grind hunters and Bowie's this way and never get the blade too hot. I also do my small ATS34 and 440C blades this way. I had a order for a 16" blade fishing knife in 440C and it was suggested by Paul Bos to profile and drill the needed holes, then heat treat it and then hollow grind it, I did it that way and it turned out great. Try it you will like it. Gib

[Rocket_Jason]

You know, I always kinda figured it was ok to grind after you hardened it. I'll give it a whirl the next time I forge one out. Thanks for the replies.

[AUBE]

just be carefull in the thin areas like the edge and the tip...you can build up too much heat and change the temper if youre not carefull. if you have a problem with too much heat wet grind the blades.

btw...100deg is only 1-2 degrees warmer than the human body, it wont burn ya...or did you mean an additional 100degs?

-Jason Aube

[SVanderkolff]

Thanks all for the replies. I will definetly turn down the heat on the kiln and see what that does to the etching. As well I am going to start heat treating my small blades before I grind them.
Thanks Again
Steve