Question about sharpening

[tensecondsdown]

Hi, I just made my first knife and while sharpening the blade I let a couple spots get too hot and turned blue and sizzled when I dunked it in water. The blade material is 1084. What can I do to fix it. Do I have to normalize then re-harden or do I just need to re-temper it. Thanks in advance for your help.

 

[stezann]

You can use the blade and live with a softer spot on the edge.
The only thing you could do is re-harden, and IMHO you shouldn't sharpen on motorized equipment...it doesn't need to turn blue an edge to ruin the temper.

 

[samuraistuart]

I couldn't live with that myself. If a few spots turned blue, then it is possible that other spots received excessive heat as well. Exactly why I am a big proponent of non powered sharpening. It's pretty easy to toast an edge.

In order to fix the damage, you will need to re-heat treat it. Normalizing will not be necessary at all. Just re-do the hardening/quench and re-temper. That's just me tho. Like Stefano said, you may want to just deal with the softer edge...that's up to you.

 

[tensecondsdown]

Thanks for your help guys!

 

[Ryan J]

I wonder if the edge being ground completely down would cause warpage during quench? Isn't the apex supposed to be around .025?