Fixing and Fettling a Wooden Plow / Plough Plane - Part 3

Uh, Houston?  We have a problem.

Make that a few problems.  Last post I described getting the skates in line with each other.  Well, after plowing my test groove with the 1/2" iron, the rear skate was out of alignment again.

Front of rear skate (right) lifted

This next picture shows the skate not quite seated in its groove.  Enlarge the picture and you'll see a gap that shouldn't be there.

Arrow points to the gap

All it took was a tap with a wooden hammer to re-seat it.  But I found out that the simple act of tapping in the wedge when setting the iron was enough to knock it out-of-whack again.  I'm sure the act of planing would do it, too.

I have to think about what to do about this, but if anybody cares to comment, I"m open for suggestions.  I'm thinking I have two options: allow the skate to lift and from that position file it down to be even with the front skate (don't like this idea at all), or plug and re-drill the screw holes to make the skate more snug in its groove in the plane body.

UPDATE: I had failed to tighten the skate screws all the way down.  The screws are a little off center in the direction that should pull the skate into its groove, so I hope this is all I needed.  We'll see.

Screw holes are a little off center from the skate's countersunk holes,
which should pull the skate upward

The front of the rear skate is in line with the plane body's bed angle.  The lower front of it extends about 1/16" further than the upper front portion and is filed to a point so that the groove in the back of the irons can mate with it.

Portion of skate filed to a point - a little proud of the rest of the front of the skate

Here it is at a different angle (from above and to the right) to try to show the angle filed on the front of it.

The point filed on the front of the rear skate

The backs of the irons have a groove that sits on the pointed front of that skate.

Backs of the irons showing the groove that mates with the skate

Looking through the mortise hole that houses the iron and wedge, you can see that the pointed portion of the skate should be proud of the rear wall of the mortise.

Tip of rear skate just visible - it's just proud of the rear wall of the mortise

I think the purpose of the pointed front of the rear skate is twofold.  First, it keeps the iron from moving laterally.  The back ends of these irons are typically 5/8" wide, but the mortise for the wedge and iron is a little bit wider, so there is a little wiggle room.  Seating the groove of the iron onto the point of the skate keeps is steady.  The second reason for the skate shape is to center the iron.  When the iron, plane body and skate are properly constructed the iron will be forced to the center.  Not that it matters if the iron is perfectly centered though, because the movable fence determines its position on the work piece.

Regarding the irons I purchased, the jury is out.

My original 1/2" iron at top, and new (to me) irons in box

Plow plane irons are numbered #1 through #8 with sizes 1/8", 3/16", 1/4", 5/16", 3/8", 7/16", 1/2", and 5/8" respectively.  So my 1/2" iron is a #7.  I purchased the smallest 5 sizes.  Unfortunately, only one of them is close to the nominal size.

#1 iron by Dwights French & Co. should be 1/8", but is 11/64", way oversize!!

#2 iron by Wm. Ash & Co. should be 3/16", but is 13/64"

#3 iron by Peugeot Freres should be 1/4" and is more than 1/64" oversize

#4 by Meaney (or maybe Heaney, or Beaney?) & Wood should be 5/16" and is 1/64" oversize

#5 iron by James Cam is close to right size at a strong 3/8"

I've read that British plough plane irons often have a different taper than American made irons.  Dwights French is American, Wm. Ash and James Cam are British and Peugeot is French (could not find info on the #4 iron), so all bets are off that these irons will all have similar tapers to my Ohio Tool iron and fit in the Ohio Tool plane with the current wedge.

Here are the irons from the back end, highlighting how different they are.

All very different: #5, 4, 3, 2, 1 and my #7

Blurry pic of back ends in profile.  How are you supposed to strike the thin ones to advance the iron?
#2 iron is already folded over (see individual pic above)

The business ends - some different shapes

The grooves - all very different again

Well, the jury has come back.  I sent these irons back to the seller for a refund.  I contacted Josh at Hyperkitten, but he's got no American made plow irons right now.  Patrick at Supertool is trying to sell me on an English set.  Gotta keep looking.

Regarding the irons, I've got so many questions!

• How well does the groove need to fit the point of the skate?
• Should the tapered length of the irons be perfectly flat on back and front (grooved side) to mate with the plane bed and wedge?  I thought I read somewhere that the tapered length is typically concave on the grooved side.  If this is true, then why?

Bevel (grooved) side is a little concave

Back is fairly straight, but not exactly
(Man, is it tough getting decent photos of this!)

• As a tapered iron wears down, it gets thinner, meaning the wedge will sit lower in the plane. This wedge has a groove to match with the plane body to eject shavings.  Does this matter?

This little curve at bottom of wedge is already lower than the matching curve in the plane body

Garret Hack's excellent book, "The Hand Plane Book" doesn't give specific information about my questions.  I don't know where to find the answers, even after searching the internet.  I wish there was somebody to talk to about this stuff, but this knowledge is rapidly being lost.

BTW, just to record this somewhere, My 1/2" iron's cutting width is dead-on 1/2" (0.498") and it is a little narrower at the grooved side for clearance in the cut.  At its thickest point (where the bevel starts), the iron is just shy of 5/16" thick (0.309"), three inches back from there it is just under 1/4" (0.242") thick and 3 more inches back it is about 3/16" (0.185").  A little trig gives a taper angle of 1.2°.

I'll post more about this when I finally get a better set of irons.  Then I'll try fitting them and may have to make new wedges.  I probably need a new wedge for the 1/2" iron anyway, as it's pretty mangled where you tap it out.

Fixing and Fettling a Wooden Plow / Plough Plane - Part 2

In the first part of this series I wrote about fixing the broken screw arm post, removing a section of damaged or missing threads on each screw arm, and patching and re-drilling the hole for the depth adjustment locking thumb screw.  Those things allowed me to test the plane out, as I successfully plowed a 1/2" groove.

First and only test groove made two years ago

I knew then that there were other things that needed attention and I'm finally getting to them, as I'd love to get this plane into regular use with the new smaller-width irons I recently purchased.

There is nothing square about this plane.  Maybe things were square when it was built, but now - not so much. I though a lot about what surfaces should be square and flat and decided on a few.  First was the fence.  The face of the fence that rides on the workpiece should be flat.  And it should be square to the top surface of the fence where the screw arm posts are attached.

These two surfaces should be flat and square to each other

Here's a closer view of the end grain of the fence.  Check out the boxwood section dovetailed into the bearing face of the fence.

Boxwood wear surface was let into the fence

Boxwood is used because it's a lot tougher than most woods.  But this plane was apparently used extensively.  If you look closely, you can see the boxwood surface is concave.  It was worn down so much, the whole of the boxwood surface was far lower than the beech area, which would never touch the workpiece except when plowing very deep grooves.

That's a lot of daylight under the square

After planing down a couple of high spots, I checked for twist.

Holy crap, Batman!

I worked the two surfaces until they were twist-free, flat and square to each other.  I was pleasantly surprised at how easy the boxwood was to plane.  I thought it might be like planing purple heart or lignum vitae (neither of which I've planed, but have heard they're very hard).  But it planed beautifully.

That's better

The next area I worked on was the bottom surface of the plane body and the side wall to which the skates are attached.  I first glued a small crack that I saw on a fragile area that could have popped off while planing.  There was evidence that this area may have been patched before.

Arrow is at most fragile point

I got the bottom flat and twist free, as well as square to the adjacent wall.  This made the skates perpendicular to the bottom surface.  Prior to working on that sidewall, the skates were not in perfect alignment with each other.  But they are better now that the wall to which they are attached is flat.

Checking alignment by looking from end

And checking with a straight edge

The bottoms of the skates that ride on the workpiece have a convex curve.  I need to file them flat and parallel to the plane body's bottom surface.  I'll get to that later.

One more area where flatness and squareness are important is the bottom of the screw arm post.  This surface mates with the upper (and now flat) surface of the fence.  Not only should this surface be flat, but it should also be parallel to the screw.

Testing for flatness with a straight edge

Neither post had a flat bottom surface, so I marked high spots and started removing material.  At first I used a block plane, but the surface is so small that I couldn't control the plane well enough.  Then I tried using a scraper to remove high spots, but that also wasn't good enough.  I finally went with sandpaper, pulling the arm assembly over the sandpaper to flatten it.

Flattening the bottom of the arm post

I checked that the bottom was parallel with the screw by holding the post flat on the work bench and gauging with a ruler at both ends of the threads.

About 1 1/8" here ...

... and 1 1/8" here

I assembled them with the fence and used winding sticks to see if the two screws were parallel with each other.

Shocking!!  As good as I could have hoped for!

I was very satisfied with this, but I'll still need to see if the fence's bearing face is parallel to the skate when the plane is reassembled.  If not, I'll tweak the bottoms of the posts to get it right.

Aside from all these out-of-square issues, there was a small problem (that could be a large problem later) with the depth adjustment.  The mechanism works fine, but the mortise that houses the brass plate that is screwed to the plane body is damaged.

Plate not seated properly in mortise

Rear aspect of the area - note the crack at bottom right

Front aspect - smaller crack bottom left

I believe the locking screw has been clamped so hard on the depth adjuster that it has blown out the thin wall on the left side of the mortise (at the bottom in the above pictures).  You can see the crack that has formed, especially at the rear.  The locking screw works as in the following picture.

Locking thumb screw pinches the brass portion below the plate so the adjuster can't be turned

It pushes the whole mechanism against the thin wall at left side

In the following picture, I've removed the screws and pushed the adjuster into its proper position.

Adjuster in proper position

If you look closely into the screw hole, you can see the hole has been worn to an off-center position.

Can see the hole in the plane body is off-center from the brass hole

So I decided to drill out the screw holes, plug them, and re-drill them, hopefully with better centers.

Cutting some plugs in beech - needed two for each hole to get enough length

Shaved them a bit since they are tapered from the plug cutter and I don't want to wedge the plane body apart

Two plugs glued into each hole

I used a router plane to flush them up after the glue had set.  Notice on the sidewall down inside the mortise hole there are drops of glue squeeze-out.  Apparently the stresses applied by the locking screw were enough to crack apart the body in this area.  So I clamped the whole plane body in a bench vise until the glue set up.  Maybe the glue that squeezed into the crack will seal it.

When the glue had set, I drilled new holes for the screws, trying to be as accurate as possible.  I also tried to get some superglue into the cracks along the thin wall and clamped it in the vise to pull that wall back in.

Holes drilled and superglue applied in cracks

Finally, I glued a couple of thick shavings into the void on the left side where the plate had shifted to.  The depth adjuster is being used as a clamp to hold these shavings in position.

Shavings glued into to open area on left.

And here's how it came out.  The cracks near the thin side closed up a bit and the whole mechanism is in a better position.

Looking much better

Blurry pic from the other angle

After the plane was reassembled, I checked the fence for parallel with the skates.  Couldn't be happier with that.

Looks pretty good, but lets measure

Just shy of 12/32" at top

Just shy of 12/32" at bottom - BANG ON!!

The the skates had to be filed flat and parallel to the bottom of the plane.

Before filing - lots of light coming through at front and back

This took only a few minutes with a flat file, followed by light sanding.  Then it was time to try making a groove.  Still using the original (to me) 1/2" iron, which was perfectly sharp from a couple years ago.

Not bad

I started at the far end and gradually moved backward, taking longer shavings.  It was little difficult and the iron dug in and removed too much material at the far end.  But I can tell this plane will require practice.  And I can't wait to see how it works with the narrower irons.

The next post will be about the irons and wedge.