Missed on the heat treat

[Justin Presson]

Just thought I would share this with you guys as a learning experience.
I had a gut feeling that one out of the 4 bowies I'm working on may have not properly hardened. As you can clearly see in the picture I only got about 3" of the edge from ricasso to tip to harden.
This was the second blade I quenched. I was using canola oil and after I had quenched this blade it felt like towards the tip the file did not skate as well as it should have. I checked my oil temp and it was 125 degrees before I quenched the first blade, after the second blade(this blade) I checked it and it was at 180 degrees. I added 2 more gallons, removed it from the burner and it cooled back down to 125 or so before I quenched the other 2. I checked in between my other quenches to make sure I was withing range so hopefully 3 of the 4 were successful.
Just thought I would share. I have got to purchase some parks in the future here.
Hey at least I practiced on grinding in fullers on this one before I do the other 3.

 

[Dennis Morland]

Bummer. But, I would attempt to heat treat it again. Probably skip the hamon. I bet it will harden.

 

[opaul]

I’m with Dennis. Treat it again. that’s a really nice bladeshape.

 

[J. Doyle]

If that's 1075 with low manganese it will be a very shallow hardening steel and canola will be less than optimal.

 

[Justin Presson]

Well one of them is good! I have not finished the other but fingers crossed.

 

[John Wilson]

That design is bad ass! How hard was it to grind the fullers so straight?

 

[Doug Lester]

Great design on that knife. I'm with everyone else in recommending that you go back and re-heat treat the one that failed to harden. If you are using a shallow hardening steel 180° on the canola may have slowed the heat transfer rate too low to beat the nose of the curve.

Doug

 

[Justin Presson]

Great design on that knife. I'm with everyone else in recommending that you go back and re-heat treat the one that failed to harden. If you are using a shallow hardening steel 180° on the canola may have slowed the heat transfer rate too low to beat the nose of the curve.

Doug

That's exactly what I think happened too. Lesson learned. I will be buying some Parks in the future.

 

[Alden Cole]

If that's 1075 with low manganese it will be a very shallow hardening steel and canola will be less than optimal.

Why is it that 1075 doesn't harden well in canola? Is it too slow? Personally, I can't afford Parks yet, so is there anything better than canola? Thanks!

 

[AkWildman]

How big is your quench tank,mine holds 5 gallons and I usually try and do about 4 blades at a time when using my oven.I do one then stir the oil wait a minute or so then do the next one.