Making a low angle miter plane

I like to use a lot of hand tools in my everyday work.  They are cleaner, quieter, and safer than power tools.  I also find that removing wood slowly makes me less likely to mess up.  When you are sneaking up on the correct size, you’re likely to hit it dead-on.

Even though I’m pretty good at planning and hand-sawing, I’ve always struggled with shooting.  This is where you put a piece of wood in a 90° jig and trim the end grain with a plane until it’s dead square.  Shooting makes even the squarest piece of wood even squarer.

I’ve just never been that good at it.

I’m sure some of the problem is technique and some of it is my shooting boards, none of which have been all that well-made.  But when James Wright from Wood By Wright contacted me about doing a collaboration and then suggested we both build low-angle planes, it seemed like the perfect opportunity to build a dedicated shooting plane.  Maybe a well-made, low-angle plane would make me better at shooting.

 A vintage miter-plane. Hard to find and pricey. 

I was influenced by some of the beautiful antique miter planes I’ve seen online; elegant rectangular infills made from brass and steel and exotic woods.  Not only do these look nice, the right angles and straight sides make them well-suited to sliding along a shooting board.  No one’s really made these planes for at least a century.  Stanley produced an iron model called the No. 9, but these didn’t sell in huge numbers and are rare and pricey on the used market.  Same thing with the reproduction model made by Lie Nielson; too much money.

What really inspired me are the all-wood miter planes that used to be fairly common in cabinet shops.  These planes have pretty much all turned to dust, but just the fact that you CAN build a miter plane out of wood makes it seem approachable for the home craftsman.  I’ve made several planes in the laminated Krenov style.  They’re easy to build and surprisingly effective.  In theory, a miter plane could just be a Krenov with a low bed angle.  Everything else would be the same.

I started with a prototype in red oak.  I made it long, tall and wide so that it would take a big, 2 inch iron and have lots of registration surfaces.  I also innovated little bit with the inside. I’ve never liked the pin-and-wedge system that Krenov planes use to secure the iron.  It’s a genius bit of engineering, but kind of a pain to make.  I also really like the high tension and easy adjustment of a lever cap and a steel pin.  These are easier to make and allow you to dial in the exact amount of tension you want on the blade.

I knocked out the prototype in a few hours and it worked well right away.  It actually made a great low-angle smoothing plane and took nice shavings with almost no effort.  On the shooting board, it worked okay, but couldn’t really compete with my Stanley 4 1/2.  I think the Stanley’s greater mass just gives it the momentum to power through tough end-grain cuts in a way that a light-weight wooden plane just can’t match.

No problem.  I pretty much expected these issues and I used the prototype to sort them out.

I knew that the final plane would have to be heavier and more massive.  I might have used a heavy exotic wood like lignum or cocobolo, but I don’t have any of these in large enough sizes for plane-making.  I’ve worked a fair bit with plastics in my fabrication business and I know that materials like acrylic are easy to work with and durable.  I also recently learned that the famous plane maker Ken Holtey uses acrylic in some of his infill planes because it eliminates the expansion differential between wood and metal.  I do have some acrylic, but I settled on Corian, which is an engineered countertop surface made by DuPont.  It’s mostly acrylic, but is heavier, denser, and more wear-resistant.  I figured it would make an excellent plane.

I wanted to keep the easy construction of a laminated plane, but I wasn’t sure that thin cheeks made from Corian would be strong enough.  An easy way around this problem was to just make the cheeks out of steel.  I have plenty of scrap steel laying around and enough tools to work it.  Steel sides could be strong while being very thin.

I started by making a blank from five sheets of Corian.  I tested several different adhesives, but I found super glue to be the most effective.  It’s also cheap. I used the table saw to trim the laminated blank down to just over the width of my blade.  I then sawed the 37° bed angle.

I should stop here and explain the bed angle.  Most low-angle planes are bevel-up.  This design allows the iron to be supported all the way to the edge, but it requires a very thin bed.  The effective cutting angle of a bevel-up plane is the angle of the bed PLUS the bevel angle of the iron.  So, even if you have a very shallow bedding angle of 12° and then you add a similarly shallow 25°bevel, you still end up with a 37°cutting angle.  And 12° makes a very thin and fragile bed in any material except for steel or iron.  Wood and Corian are too weak and too brittle to be sliced this thin and still handle the forces of supporting the blade.  Luckily, there’s an obvious solution.  If you just switch to a bevel-down design, then your bed angle and your cutting angle are the same because there’s no bevel to worry about.  By switching my design to bevel-down, I was able to get a thick bed and a low cutting angle.  The only problem with this approach is that the bed can’t support the iron all the way to the edge, but I got around this by using an extra-thick 3/16 inch iron.  (I also made this iron from scratch.  You can read about it and watch the video.)

With the center section cut out, I cut the escapement on the band saw and chamfered all the sharp edges, just like I would if I were making a Krenov plane.  Once that was done, I grabbed some plain, hot-rolled bar stock and started to cut the pieces for the sides. Of course, my metal-cutting band saw would have to go down right in the middle of this project.  I went to make the first cut and found the saw’s switch as floppy and useless as a wet noodle.  Broken. The replacement was cheap, but would take two days to arrive in the mail.  Drag.

Tools and materials in this project:

High-Strength Epoxy
Starrett Tap Wrench
MAP-Gas Torch
Gas Cylinder
Spray Adhesive
Norton Sharpening Stone
Solvent Cement for Acrylic
5 Minute Epoxy
Drill-Press Clamp

Since I had agreed on a release schedule with James, I couldn’t let a tool slow me down.  I grabbed my angle grinder and got the steel sides roughed-out.  I then cleaned them up on the belt sander and epoxied them together.  Having the two sides glued together meant that I could work on them as a single piece and have perfectly mirror-image sides when I was done.  I flushed-up the edges, cut curves, and drilled and counter-sunk holes for fasteners.  I used 5 minute epoxy because it’s not that strong and it breaks down when you heat it up.  All the heat from the sanding and drilling weakened the epoxy, and by the time I was done shaping the sides, they just peeled apart.

I also made a lever cap out of a thick chunk of scrap aluminum.  Aluminum is my favorite material for this sort of thing because it’s strong, but soft enough to cut on a regular bandsaw.  I got the basic profile cut, finished on the belt sander, and tapped it for a ¼-20 thread.  The hole was quite deep and even though it was just aluminum, I really appreciated my Starrett Tap Wrench, which held the tap very tightly and gave me excellent leverage.  I don’t generally recommend such expensive tools, but the cheap tap-wrenches that come in tap-and-die kits just don’t compare.  I then made a cap screw out of a bolt, some black acrylic, and a bit of copper pipe.  It actually looks very nice.

Now I was time to assemble the whole thing.  An interesting property of Corian is that it’s too brittle to hold a wood screw, but you can tap it for machine-screw threads.  So I temporarily super-glued my steel sides on to the center block and used the holes in those sides as guides to drill and tap the Corian for brass machine screws.  Once the fasteners were in, I used the bandsaw and the belt sander to take off all the sharp edges and make the plane comfortable in the hand.

Even though I started out being inspired by the rectangular miter planes of the 17th and 18th century, I’m also very impressed by the Veritas Miter Plane.  I’ve never actually used one, but I think its genius the way they’ve made a plane that’s flat and straight enough for shooting, but also ergonomic and usable as a regular, low-angle smoother.  After I saw this concept, I couldn’t see any reason to leave my plane shaped like a brick.  I used some antique coffin-smoothers to get the rear shape correct and I made the front into a gentle curve.  This plane is still too heavy for long-term use as a dedicated smoother, but it’s now comfortable enough for specialized tasks like flushing up edge banding, or trimming long grain in casework.

Once I had the shaping done, I knocked the temporary assembly apart, refined the shape of a few things and then put it all back together with super-glue and brass screws. I even put glue on the threads of the screws so that the whole thing would be locked together as tightly as possible.

Once it dried, I needed to lap everything flat, so I glued some 80 grit paper to my table-saw and went to work. This took FOREVER. The bottom was no big deal, and I had it flat in a few minutes, but I’d deliberately left the brass screw-heads proud of the sides and these had to be ground flush. Then it was on to flattening the steel sides and this was an ordeal. To build the plane, I’d just used some cheap, hot-rolled bar stock I had sitting around. I’ve seen other people use precision-ground O1 tool steel and I never knew why anyone would spend that kind of money to make the bottom of a plane.

Now I know.

That hot-rolled steel was covered in tough mill-scale and the surface was wavy as the ocean. I got it flat and polished, but it took hours. With that chore out of the way, there was nothing left to do but open the mouth and test the plane out.

It works. Really well.

First, I tried it on the edges of boards and it took beautiful shavings. I’m really thinking about making a low-angle plane just for general bench-work. Of course, the real test is the shooting board and the plane really excels here. The low angle and high mass of the plane make it do exactly what I wanted: take crisp and easy cuts off tough end grain. It’s really amazing to work with and works much better than even my beefy No. 4 1/2.

I’m also really happy with the way the plane looks. It’s actually a lot like an infill plane. I’ve recently been geeking-out over Konrad Sauer’s amazing modern infill planes and I think a bit of that influence crept into my work. Of course, this isn’t an infill. It’s an odd laminated-Krenov-infill hybrid. But it looks cool.

So, I’m happy so far, but I’ll be paying a lot of attention to this plane as I work with it. Is Corian really a good material for plane-making? Will it stand up? Will the mouth chip or wear? I imagine that it has to be better than wood, but I won’t know until I use it. A lot.