Recently I built a fixed fence style plow plane that cuts a 1/4″ groove 1/4″ from the edge of the material. I did this to avoid building a good movable fence which very likely would have been more work than building the rest of the plane. I realized as I thought about it, that most of the work I wanted to do could easily be done with a plane with a fixed fence so why bother with all the added complexity.
Once I used this plane a few times though I started thinking about how nice it would be to have a matched plane that would cut a tongue so that I could have a dedicated tongue and groove plane set.
I had some leftover steel from an old Stanley blade so I decided to give it a try. Immediately I discovered that I had to make some choices. The most common configuration I have seen by far for a plane like this is to use a single blade with a gap cut in the blade for the tongue and then some kind of depth stop.
Generally, when you are building a tool that has been around for a long time you are working at your own risk to go against convention. There is usually a very good reason that the old tools were built the way they were. However, I was not convinced that I could get a perfect match between the two and once a tool like this is built it is very hard to adjust it. So I made a departure from tradition and essentially made two planes that were bolted together with a spacer between that could be easily adjusted to make various widths of tongues. This way if the tongues were a bit too tight or too loose I could adjust that easily by adjusting the thickness of the center shim.
This did mean however that there were two separate blades in this plane and adjusting the depth of cut would be a bit more of a challenge. Time will tell if this is a good idea or not. I may write a follow up to this story after I have used this plane a while to report on how this experiment works in everyday shop use.
On to the build
I started by making a rough sketch of this plane, since this plane had far more parts than a usual Krenov style plane I wanted to make sure I did not confuse the many pieces at some point and ruin any of my work.
I began this build like I did the last plane I built – with the blade. Once again I just used what I had on hand, in this case I cut two strips from an old Stanley iron with a cut-off wheel on my Dremel. I find this to be the cleanest and most accurate way to cut tool steel.
After that it just took a few minutes for each blade to clean and straighten them up a bit on the bench grinder and I was ready to build my plane. I always start with the blade because I find it easiest to match my wooden parts to the blade. And worst case scenario, I can always grind the blade slightly later if needed during the final fettling. Making blades our of old stanley blades is not ideal. Ideally the blades should be much thicker. But this is my third plane made with thin blades like this and my first two worked surprisingly well so I have no reason to think that this plane will not.
Making the body starts with cutting and thicknessing the various pieces. The thickness is determined by the blades we just made and the thickness of the groove the matching plane cuts. Once done we are ready to start construction.
I decided early on that the easiest way to build this plane would be to build two planes and then find a way to accurately clamp them together around a shim that is exactly the thickness of the groove that my plow plane cuts. Since this is a wooden plane and subject to wear and weather I felt that this design although not as good looking would be longer lasting and easier to tune up later. So overall I did what I usually do which is – to favor function over form.
Step one is cutting the bed pieces for the blades. I choose 48 degrees for the bed and 58 degrees for the wedge, leaving me with a 10 degree wedge. This angle is the one I obsess about the most. Too low of angle on the wedge and it will wedge so tight it is near impossible to remove especially on a plane with light, small irons. Too high of an angle however, and obviously it will not hold the blade tight during use. I have tested this angle a bit and it seems to hold, but comparing it to historical examples I do not think it would be wise to try anything much steeper than 10 degrees. I also cut my wedges a bit narrower in width than the opening, because I have found on my other planes with small narrow irons that it is often easier to loosen the wedge by moving it back and forth in the slot than by the usual smack it with a mallet method. The blades do not seem to have enough mass to shake everything loose on their own.
One final note on this. I plane the wedges to a taper so that they fit very well down near the mouth, but have even side to side play at the top to allow me to loosen them up for sharpening and adjustment.
Glue up is the really important part, I usually cut all my pieces just a bit oversize to allow me to glue up with my wedges in place this saves a lot of hassle later. Truing up the edges with a plane after glue-up is far easier than trying to fit the wedge later by trial and error. So as you can see I glue up with the wedges and blades in place.
Also, do not use any more glue than necessary because too much glue will cause the pieces to swim all over the place making it harder to precisely position them. It will also cause an annoying amount of squeeze out. I find a thin coat on both pieces is the best for this kind of work, rather than my usual thicker coat on one piece and rubbing them together.
Assembly and fettling
Now it is time to begin the challenging part. Getting all these pieces to work together. As I mentioned earlier I built this plane essentially as two planes. One that ejects it chips to the right and one that ejects it’s chips to the left. Between these two planes I am clamping a shim that is the thickness of the tongue that I want to leave in my work. This shim also serves as a depth stop that will bottom out when the tongue is high enough.
This looks like it might be difficult but this is really one of the easiest steps in building a plane like this. You drill a hole with a forstner bit to begin then egg it out with a combination of chisels, gouges, and rasps.
That took me to the point at the right. Now it is time to think about alignment as I finish this project. I started with the center shim and planed it to what I thought would be the final thickness. Then I cut two brass pins 3/32″ in diameter. The diameter does not really matter as long as they are not too thin. I then drill the center shim to receive these pins, making sure they were perfectly square and fit very tight in the holes.
With this done I used the center shim to gauge exactly where the holes in the two planes should fall. Once I was sure of the position I tapped on the pins leaving marks exactly where they needed to be and since the pins were relatively small they penetrated far enough that they served to guide the drill bit.
Now the plane could be assembled and disassembled at will without ruining the alignment. This turned out to be very important because fettling this plane turned out to be a real challenge.
Bolting it all together with large stainless steel machine screws was next. I chose square nuts mostly because the hardware store had some nice looking ones, and as an added bonus square nuts are really easy to let into the wood. I just needed a few taps with a 3/8″ chisel to turn a 3/8″ hole into a 3/8″ square and I was done.
I was pretty excited at this point but in fact I still had a couple of hours of fettling to go before I could honestly say that this plane was a match to my other plane. In the end I needed to add a few sheets of paper to my shim in order to get the fit I wanted between the tongue and the groove my other plane cuts. As big a pain as this plane was to build with two blades and all, I think I am still glad I went this direction. As both planes are wooden planes I expect wear over time, and at that point the complexity that drove me nuts building this plane will become an advantage making future repairs and adjustments relatively easy.
What I learned
- Making a plane that works is easy.
- Making a plane that works well is harder.
- Making a plane that works well and looks great is harder still.
- Making two planes that look good, work well, and match each other exactly – CRAZY HARD.
But I had fun, and they both work now. Not sure about the looks though.