Remediating a pitted plane iron

[David Nebenzahl]

Another episode in the saga of my refurbishing an old Millers Falls plane.

So I got the thing for, like, $5 at a local flea market. It was

*completely* rusted. Seemed like a nice challenge for my old-tool revival propensity.

I threw it into a bucket of old motor oil for a few weeks. After retrieving it and using an impact driver to loosen the rusted-together screws, I cleaned off the gunk, then subjected all parts to my Dr. Frankenstein apparatus, my electrolytic rust-removal rig (OK, all it is is a big honking DC power supply, no cool sparks and buzzing noises or anything).

Anyhow, to make a long story shorter, the plane is now back together and actually able to fulfill its life aim. But not without some extra fooling around.

Most of the plane cleaned up surprisingly well; the body is actually pretty smooth. But some parts were so rusted that they actually were pitted. Of course, the plane iron was one of those parts, especially just under the chip breaker.

After grinding the iron, the edge was quite rough because of fairly massive pits. What to do? (Apart from getting a new plane iron, that is.) I needed to remove material from the top of the iron to get under the level of the pits, just at the leading edge. My tool of choice here would have been a belt sander (well, sure, a milling machine, but I'm talking about the sort of tools a DIYer might have.)

After reviewing the tools I actually have, it seemed to me that a few passes with a cut-off blade might just do the trick. I only needed to remove a couple "thous" of metal, right?

So I adjusted the blade so it was just barely kissing the work. After a few passes on a piece of scrap steel, I took a deep breath and started pushing the plane iron through the saw. Made a bunch of parallel passes, starting at the very edge. And just as I had hoped, the wheel gradually wore so that by the time I was about an inch or so away from the edge, it was barely spitting sparks anymore.

Looking at the iron, the parallel cuts were pretty evident, but they were nice and even. The next phase called for a lot of elbow grease. I ground the top of the iron on my big piece of sandstone charged with valve-grinding compound. Little by little, shiny areas appeared near the front edge.

The final result (so far) isn't perfect. There are still some pretty deep pits, though they're pretty well back from the edge, and there's one nick in the blade. But the plane can still sing its song and cut a nice shaving. It's slated for rough carpentry work for the time being. Then I figure the next time it needs sharpening, I'll do a little more cutting and grinding on the blade.

It's actually a very nice plane. Nice and heavy in the hands, no chattering or other nonsense.

[Bob AZ]

Disasemble completely separating all the metal from whatever other parts.

A 24 hour or more immersion in a gallon of white vinegar would have been a better choice. Then some polishing with wet or dry emery cloth using cutting oil. Messy but the results would have been better.

Bob AZ

[Andy Dingley]

Get a whole new plane (which might be even worse).

Then get a third new plane, which can be a real dog.

Use the 3rd worst body with the 2nd worst iron to make a scrub plane (probably by opening the mouth up too). Crown the iron a lot. This is a great use for a #4 that's beyond much other use, and a handy thing to have around (until you discover wooden planes and how much lighter they are).

Use the 2nd worst body with the best iron to make a bench plane. Crown the iron a bit and try to get the pits out of the back. Really a jack plane's better as a #5 and a bit longer, but a #4 will do if it's what you have.

Buy the best body a new iron and set that one up as a smoother; straight iron, just relieved a bit in the corners, and with the smallest mouth you can make work well.

If the worst iron was a decent bit of last-half-century funny-alloy steel, then anneal it, drill holes in it, harden it up again and make yourself a dowel plate.

If it's old (pre-war) laminated steel, either fix it up, or make marking knives from it.

With three planes you're on your way to having a half-decent workshop and a proper breeding colony of them.

[RicodJour]

Well put. Brought a tear to my eye. I swear I could almost feel my knuckles dragging.

R

[Phisherman]

I see all kinds of rusted tools at flea markets and wondered who would really buy them? After all that work you could have just bought a LN then made a beautiful piece of furniture. Some pits would be OK for a secondary plane or as a loaner to protect your good tools.