Chipped plane blade

[Bob Glenn]

I have an old woodie skewed Rebate plane that I use on occasion. It wasn't cutting right and I noticed a one eighth inch chip had come off the toe of the iron. I also noticed earlier that there was a small chip in the center of the iron, but I didn't sharpen it at the time since I could live with it.

I have ground the bevel on my water cooled Tormex, so I know that I did not over heat the iron when gringing the bevel. However, a previous owner may have over heated the iron and quenched it, thus making the blade too hard and easy to chip.

Before I go about grinding an eighth on an inch off the iron, would annealing it in a 400 degree oven for an hour or so, fix the problem? Thanks

[Robert Hazelwood]

At 400 degrees you'd be tempering it, not annealing.

It might tame the iron a little bit. Assuming this vintage steel is similar to W1, tempering at 400 degrees should give a hardness around 61 Rockwell, which is about where I'd want it for a plane.

[Charles Guest]

Grind the dings out, hone it, use it, see if it chips again. Start simple before invoking metallurgy.

[Zach Dillinger]

Agree 100% with Mr. Guest, grind it out and see what happens.

[Bob Glenn]

I guess I meant tempering and not annealing. Sorry, I knew better, just couldn't come up with the right word.

[Bob Glenn]

Okay, here is what I did. This iron was probably quenched but never tempered. More that likely, due to its age, the smith probably laminated the tool steel on to the softer steel shank and quenched the iron. Probably, then, polished the back and "ran the color" down the iron until straw showed at the tip. This would have left the steel further up the iron to still be brittle. Subsequent sharpening finally got into the brittle tool steel up the iron and started chipping.

I ground the chips off. On closer inspection, there were several smaller ones. Reground the bevel from 25 to 30 degrees, then put it in the over at 400 degrees for twenty minutes and left it in the oven to cool for two hours. Coming out of the oven, the laminated seam was clearly visible with a nice even straw color on the tool steel. I reflattened the back and reground and adjusted the skew to match the plane body. Trued up the plane sole and sides a bit with another plane.

It now cuts great, but time will tell how durable the cutting edge is. I'll report back if there are problems down the road. Thanks for looking. Bob Glenn