Retempering a plane blade

[Wade Lippman]

I bought a German #3 really cheap on ebay. A slightly more knowledgeable friend said the body was pretty decent, but the blade had some blue staining that meant it had gotten too hot during sharpening and lost it's temper. He says it can be fixed by heating and quenching it, but isn't familiar with the details.

Can you point me in the right direction?

[Jim Koepke]

Usually the blue area from over heating a blade during sharpening is small enough that it can be ground out if need be.

In my earlier "learning to sharpen" days this was occasionally done to a blade. I would just use them as is knowing they would wear a bit faster.

jtk

[David Weaver]

How much blue, is it just at the edge? It takes a fairly substantial setup to reharden a bench plane blade.

[george wilson]

Yes,just grind the blue away. If you try re hardening a beveled plane blade,it is certain to warp across its width due to the difference on surface area on the side where the bevel is. Besides,you cannot be sure exactly what tool steel the blade is made of,or what to quench it in,how hot to get it,etc..