Lee Valley has just released a conversion kit for their small plow plane, which enables the plane to accept wider irons, including cutters that make tongues. I have owned and used the plow plane for about a year now, and I always enjoyed using the little gem.
The back-story: not long ago I picked up an old Stanley 45 combination plane with the intention of buying a set of tongue-and-groove irons for it, but being accustomed to the Veritas plow plane, the 45 seemed heavy and cumbersome in use, so I stowed it away. When Rob Lee dropped big hints in the WoodNet Hand Tools forum that Lee Valley was developing a tongue-and-groove upgrade for their plow, I decided to get one as soon as it became available.
The conversion kit consists of a second skate for the plow plane, which accommodates irons wider than the 1/8″ – 3/8″ irons it was originally designed to use. This allows the plow plane to do two useful things: cut rabbets up to 3/4″ wide and make tongue-and-groove joints.
Rabbeting with Wide Blades
I already like the rabbeting feature a lot. Most rabbet planes are pretty crude affairs, with fences that wobble and adjusters that barely work. The conversion kit for the Veritas plow addresses both problems. The fence remains secure in use and the screw-feed depth adjustment is excellent. The double skate does not offer quite as much support as the solid sole of a traditional rabbet plane, and there is no nicker for cross-grain work, so don’t list your rabbet plane on eBay just yet. But if storage space is at a premium or you just can’t afford two nice joinery planes right now, the rabbeting feature on the plow will do in a pinch.
Tongue and Groove
Setting up the small plow plane to cut a simple groove is pretty straightforward. You adjust the depth stop, the fence, and the depth of cut, and that’s it.
Setting it up with the new conversion kit is a lot more complicated. (It has really transformed the plow plane into a small combination plane, so those of you who are accustomed to fiddling with the Stanley 45 already have an idea of what you’re in for.) There are several pieces to remove and replace with different pieces from the conversion kit, and while it all fits together beautifully in the end, the assembly process can be bewildering the first few times you try it.
Here is the plow with the tongue cutter fitted and the second skate and fence exploded. I won’t go through all the steps of changing from the plow function to the tongue cutting function, as the written directions included with the kit explain the process very well. But I will say that it involves removing and replacing the depth stop as well as a set screw, and making a few other little adjustments. (Keep track of the parts you take out, because they’re small and easy to lose! Dog holes in your benchtop can become a major liability here.)
Let’s look at a few of the features of the conversion kit and tongue cutters once it is all assembled.
The tongue cutter comes with an odd little device called a “shaving deflector.” It goes where the depth stop normally goes and ensures that the shaving on the right-hand side of the plane (I have a right-handed plow) comes up out of the center of the plane rather than jamming in the mouth, which WILL happen if you try to use the tongue cutter without the deflector in place.
Then what, you may ask, acts as a depth stop when the shaving deflector is installed? The depth stop is integral to the cutter itself. It is a very small semicircle screwed to the bottom of the cutter. It is adjustable, though the largest tongue cutter (which cuts a 1/4″ wide tongue) has a default depth setting of precisely 1/4″. Good thinking, Veritas.
The one disadvantage of this style of depth-stop is that it makes the depth of cut very difficult to adjust with the depth stop set. The best I can do is to set the depth of cut first and then reach down between the two skates with a tiny Allen wrench to set the depth stop in place. Fortunately there’s not a lot of play in the depth stop, so setting it is fairly simple once you get the hang of it. It’s going to be frustrating the first few times you try it, though.
Cutting the Joint
Once set up, the plane works smoothly and quickly. The added skate makes the plane a little more front-heavy than usual. The extra mass seemed to help keep the plane in the cut, though, and it’s still not nearly as heavy as a fully-loaded 45.
Remember that, in order for a tongue-and-groove joint to close effectively, each edge must be carefully jointed. And don’t forget to mark your reference faces. Otherwise your faces won’t line up when the joint is assembled.
The irons came ground but not honed, so after sharpening up the cutting edges, I put the plane to some soft pine scraps I had nearby. The plane cuts very neatly, and in soft wood it can take a very thick shaving. A 1/4″ X 1/4″ tongue appeared quickly, and my oldest daughter had fun trying to pull the shavings out of the plane as they appeared.
Unlike a dedicated tongue-and-groove plane, but like most combination planes, the small plow is not self-centering. That means that you have to carefully re-set the fence in order to plow your matching groove. (If you have several joints to cut, I highly recommend cutting all the tongues first and then all the grooves, rather than trying to switch back and forth several times.)
Once you have removed the second skate and other accoutrements and returned the plane to its natural, grooving state, it is easiest to set the plane on top of the tongue you just cut, line the cutter up with the tongue, and set the fence from there. And DO be sure you are using the right size cutter. A 1/4″ and a 5/16″ can look awfully similar late at night.
Setting the depth stop for the groove is very simple. Set the plane’s skate on the left side of the tongue and drop the depth stop onto the top of the tongue. If you want some breathing room, slip a business card under the depth stop so that the edges of the joint will be sure to close before the tongue bottoms out in the groove.
The end-grain of this pine is pretty ragged, but you can see a tidy tongue-and groove joint.
Overall, I like the conversion kit, and I’m glad I got it. I don’t love it–at least not yet–and here’s why:
The set-up is fussy, and it’s difficult to remember the correct order of operations. Putting small pieces in and out risks losing them. Having to keep track of an Allen wrench for adjustment is annoying. It has all the usual drawbacks of a combination plane. That’s not to say that the conversion kit is ill-designed. On the contrary, it’s a marvel of engineering and machining.
Perhaps it only seems like it takes a long time to set up. I timed myself, and it took me about three minutes to set up the plane for tongue-cutting and about two minutes to get it back to a regular plow. How long does it take to install and adjust the dado blade in your table saw?
So should you sell your 45 and buy a Veritas plow plane with a conversion kit? That’s hard to say. There are no molding irons available for the Veritas, though I see no reason that there shouldn’t be. The 45 has long rods available and can work further in from an edge, although that’s not usually necessary, especially when cutting rabbets and tongue-and-groove joints. The Veritas is still easier to set up because all but two of the adjusters have knurled thumbscrews, whereas the 45 requires a flathead screwdriver for many adjustments. In my hands, the Veritas balances better on the workpiece and is generally more ergonomic.
If you already have a combination plane and are reasonably happy with it, I see no reason to trade up to the Veritas. But if you want to enter the murky waters of combination planes, then I recommend getting the Veritas with the conversion kit and picking up a few additional molding planes, which do a far better job making moldings than any combination plane ever will.