New Iron for the Veritas Plow Plane

I've recently been working on my old woodie plow plane and it got me thinking about the Veritas plow.  When I bought it, I got a 1/4" and a 3/8" iron with it.  But it seems most of the grooves I make these days are small.  I absolutely love using the wooden plow, but the irons are a little funky.  None of them are the nominal size - they're typically off by a bit (some more than others).  For example, the 1/8" iron (0.125") measures 0.157".  That's almost 22% over nominal.  But the 1/4" iron for the Veritas is spot on.

Here's the Veritas plow plane

And here's its 1/4" iron

Anyway, I thought I'd make a new 3/16" iron for the Veritas, and maybe later I'll make a 1/8" iron.  Their irons are 1/8" thick and, as luck would have it, I have some 1/8" O-1 tool steel.  So I got out the old hack saw and cut a blank to just over 1/4" wide and just over 3" long.

Sawed it out to just over 1/4" wide

The blank filed to 1/4" wide next to the factory 1/4" iron

Next was to file away 1/16" of metal in the lower 3/4" to 1" of the iron.  I probably should have hacksawn this because filing it took a while.  But I got a fairly precise 3/16" wide iron.

Iron clamped sideways in a vise

Filed the width, and also sawed and filed the notch for iron depth adjustment

I also filed the sidewalls so that the bevel side of the iron is a little thinner than the flat side, giving clearance for the iron in a cut.  The next pic shows the iron test fit into the plane.  I made the body of the iron 1/4" wide so that the iron clamping screw would act similarly to the way it does for the stock 1/4" iron.  You can also see where the lever cap meets the iron - that's why I didn't go higher on the iron with the 3/16" width.

First test fit into the plane

The notch fit nicely with the depth adjusting nut

Just a note here.  The metal that was filed away to make the business end 3/16" wide, was filed on the outer side of the iron.  You can't tell in these photos, but the plane's skate sits below the inner side of the iron.  So for the skate to properly support the iron, the metal had to be removed from the outer side.

I heat-treated the iron with a torch until cherry red and nonmagnetic, then plunged into oil.  Then because I didn't want to use our kitchen oven to temper the iron (it was 96° that day and we have no A/C), I tried for the first time to temper it using the colors that advance to the cutting edge as I heated the iron about midway along its length.  When the golden straw color reached the bevel, I plunged in oil.

I didn't get any pictures of that, but it seems to have worked well.  When I sharpened the iron, I thought I might have done the tempering wrong because it seemed I couldn't get a good cutting edge.  But after I removed a bit of material, I sharpened again and got a great cutting edge.  I'm guessing that the initial hardening treatment left the thin cutting edge area a bit brittle and it just needed to be ground back a bit.

Here's the iron sharp and ready to go

First 3/16" groove cut in some soft wood

And a 3/16" groove cut in some fairly hard oak

I'm happy to report that the new iron performed very well.  It locks into the plane nicely, is easy to adjust and cuts a relatively precise 3/16" groove.  Now I've just got to decide whether or not to make a 1/8" iron.

UPDATE: I ended up making a 1/8" iron and it also works very well.  There's something very satisfying about making your own tools.

Resolution to Plow Plane Issue

A couple weeks ago I presented a problem I was having with my wooden plow plane, especially when trying to plow a groove in end grain.

Right side of the plow, showing skates and iron

A closer pic of the skates and iron

After a bit or playing around and then noodling about it for a while, I realized that the underlying problem was that the iron(s) were not well supported by the skate.

On this 3/16" iron, I was able to slip a couple thicknesses
 of paper between iron and skate

Let's step back a moment.  The lower portion of the front edge of the rear skate has a 90° V-shape that is supposed to fit into the V-shaped groove on the underside of the iron.  But I had gaps there with some of my irons.

The front edge of the rear skate, between the green arrows, protrudes
a little further than the upper edge and has a V-shaped edge.
The yellow arrow points to where the heel of the iron's bevel rests.

Here's a typical iron's groove.  The pencil points to the spot that mates
with the uppermost part of the V-shaped protrusion on the skate.

Based on some comments I got on a Facebook post, I first tried to file the groove to allow the skate to support the groove better at the heel of the bevel (where I think it would do the most good).  But this got nowhere and I was really afraid of causing irreparable damage.

Trying some judicious filing

Another comment was about trying to bend the iron by peening the flat side.  This would theoretically make the flat side slightly convex and force the heel of the bevel to make better contact with the skate.  I did some work on one of the irons, but either I didn't peen enough or I was afraid of peening too much.  All peening was behind the location where the harder steel of the laminated irons ended and went to the location where the iron exits the plane's iron/wedge mortise.

You can see the peening marks

In the end, I just added some 0.005" brass shim material in the irons' grooves.  In some cases I needed more thickness than the 0.005" shim, so doubled it up.  It's held in place with superglue, so time will tell how that holds up.

Seeing how it fits

Glued in and excess glue scraped away, brass filed close to flush

Here's a test groove in end grain pine - much cleaner!

This was certainly not an optimal fix.  I wonder how someone might have handled this 150 years ago.  If anyone has further ideas about how best to deal with this, please let me know.

At least this ordeal did teach me one thing that I really ought to have known by now: check your specialty tools on scrap before committing them to the project wood.  If you start on a project and then find that the tool needs to be adjusted or modified, it could be very tough to get it back to the exact settings that you started with and so some parts may not align properly - in this case, grooves.