Visited by the Tink Fairy

Mike Martinez

Mike Martinez

Well-Known Member
So, tonight I heat treated 6 knives successfully and would you know, the lucky number seven wasn't so lucky. Four were O-1 and three were 1084 from Aldo. This batch was full of firsts for me... mainly the first set of knives were I didn't use any type of jig at all. No jig for plunge lines or anything else. Anyway, everything was going well until the last knife... the one that I wanted the most (funny how that works out, right?).

Anyway, it survived the quench and made it to my staging area to await tempering when I heard that dreadful TINK! I'm sure that the stress riser at the ricasso had much to do with it, but I'm not quite sure why it waited so long to split. The hammon even looks like it was going to turn out well. For what its worth, here are some photos...

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It's really not a good idea that you wait long to get the blade into the tempering oven. The steel is still under a lot of stress. I let the blades cool until they are warm, scrub the oil off in hot soapy water, and then right into the tempering oven. Then I start the heat treating process with another blade. I start timing my first temper cycle from the time I put my last blade in the oven. You'er not the first person that this has happened to, by the way. It's probably one of those things that you will get by with most of the time, just not all the time.

Doug
 
Thanks Doug for the tip on time management. I overlooked the time required to get all of my ducks in a row. Anyhow, I've had blades break before but only when using brine. This was my eight blade in Parks-50 and the first to go and fail on me. Hopefully my next attempt is less frustrating and allows me the opportunity to polish up a hamon.
 
Parks #50 is a little fast for 01, but I do hear of some makers using it. AAA would be much better. Over heating can also be a factor.
 
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Thanks LRB. I agree. I use Maxim's oil equivallent of AAA for O1 and haven't had issues. The blade that cracked in the P50 was 1084 though. It may have just been too thin since its 1/8 stock. I'm going to try and HT before grinding and see how that goes.
 
Mike did you normalize the blade before H/T.On carbon steel blade it's always a good idea as the grinding can induce a lot of stress.Just a thought.
Stan
 
One other thing to do before heat treating is to make sure the sanding lines on the blade are running length wise not across. Those tiny little scratch lines can cause stress risers expecially if the blade was over heated or not normailzed. When I get too aggressive and take the bevel too thin near the tip I will round off the blade so there are no square shoulders to reduce the chance of stress risers.
 
Thank you Stan and Barry for the advice. After looking at the knife and eliminating every factor possible, I think it was a combination of my clay (since the metal seems to have curved upward), overheating (larger grain than usual) and not normalizing.
 
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Mr. Moore, hopefully this newer blade shape works out.

Mr. Miller, you sure are telling the truth there.

I finished the blade shortly after the original post but then had a back injury and bronchitis kick my butt for a few months. At the end of February I was finally able to put it together with some of the nicer Rock Maple I've had the pleasure of working.

1084 (From Aldo) and Maple Burl (From Faron Moore)
The sheath is an unfinished but working impromptu 15 minute venture into leather working.

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That turned out wonderfully, Mike! The maple really sets it off.

I also wanted to thank you for starting this thread. As you know, I'm planning to get my first HT oven soon and seeing a bunch of like-minded guys putting their heads together to troubleshoot problems is very comforting. I have a feeling I'll be posting lots of these types of problems as I learn to HT my own knives!! :)
 
OH, the dreaded tink!!!!!!!!!!!!! Man that stinks and it looks like that was gonna be a nice one!
 
Ahh, the dreaded "tink". I have encountered mr. tink on a couple of occasions. In those instances I had ground the blade too thin before HT.
Unfortunately it was a learning experience which I had to relive twice. Been a while since *fingers crossed*
 
I had it happen a couple of times Mike it always seems to be on the clay coated blades, I have found you dont need near as much clay as I originally thought , and on the carbon steels I get much better results normalizing , because I 98% a stock removal maker I used to think I didnt need to normalize but now I do it to all carbon steel it really doesnt take too long.
 
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