Knife edge cracks

B

Bob Duguay

Joined
Aug 28, 2017
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204
Been having a hard time sharpening my knives. So I have been trying to get them thinner off the grinder. I just finished a hunting style knife in AeBL first time using stainless. Also first time hollow grinding. Well came off the grinder nice and thin. I have been dying to try stone wash finish. I know high carbon is better but went ahead and did it anyway. Blade came out looking very nice. As someone postedgou it takes along time to etch stainless and it did for me as well. I noticed that there was a chip in the blade when I was finished. Actually it was a crack. Ground down the edge on a diamond stone till it was about gone. Then went to sharpening. It sharpened up really nice. It now was Apparent there were 4 cracks.
Could I have ground it to thin? Or do you think the acid etch damaged the blade?
 
Others here have way more experience than me ... but i have noticed that if i try to get aebl too thin (say thinner than 0.008) ican start toget pull out of material...
 
You have already ground it out, so i cant really tell :-(

but what i saw were not cracks, but rather chunks of material pulled out ....
 
Pics...

G3hSVSI.jpg


GIqDo8u.jpg
 
I couldn't really see any cracks. I'd you try the brass rod test?

I take my AEBL down to about 0.007 on the platen. Any lower will start to get tear out as mentioned above with higher grits. I then move up in grit to clean up the grind and I like to slack belt it near a wheel where the belt is tight to take them pretty much a zero grind but that's with kitchen knives. I just did a couple scandies and had no issue going to zero on the grinder.

The slack belt is less agresive and run cooler.

Does you grinder have a vfd? It really helps being able to slow it down.
 
Yes I have a vfd. The edge was probably .010 off the grinder.
I can’t get a good picture but there are 4 cracks not chips.
 
Great looking knife by the way. I love the finish and have been wanting to try that myself. How long did it take to etch?
 
No expert, but maybe it has something to do with stone washing? Thin steel, high hardness and sharp stone hitting it too hard or fast?
 
Bob Duguay said:
Yes I have a vfd. The edge was probably .010 off the grinder.
I can’t get a good picture but there are 4 cracks not chips.
Click to expand...
Kinda weird. Maybe asked before: did you grind before or after HT? If before, maybe the edge was just too thin to take the stress?
 
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