Grooving Planes Part 1 – Un-Cupping the Skate

I had wanted to make some sort of grooving, or drawer-bottom, plane for some time.  I had lusted after Veritas’ Small Plow Plane, but realized that there were really only a few grooves that I cut on a regular basis.  While I may yet (probably) get one of these wonderful tools, I decided to try my hand at a fixed grooving plane first.  I stumbled upon Matt Kenney’s design on Fine Woodworking’s website, and decided to give it a try.

If you’ve been following my blog for any length of time, you know that I can never leave a plan alone – some modification will invariably take place.  In this case, I wanted a 1/4″ groove instead of a 1/8″, 1/4″ deep, placed 3/8″ in from the edge to make the groove for a standard drawer bottom.  I mentally adjusted my dimensions accordingly and started planning.

I already had plenty of white oak pallet wood that has been drying for years.  While not the prettiest choice, it is hard and stable, and would make a fine body wood.  For the skate, I wanted something especially durable.  The skate (or keel) is the piece of wood that sticks down into the cut for the plane to ride on.  It also supports the blade and defines the depth of cut and mouth opening.  After consulting the Janka hardness scale, I decided on Gaboon ebony.  It’s extremely hard, and available pre-dimensioned in 1/4″ thick pieces of the right size.  It cost a bit more, but the planes should last a long time.  When the package arrived, I opened it and inspected the wood.  Uh oh, cupped.

Grooving Plane 1
Now, the cupping was very mild, but still a problem.  This piece of wood was going to be sandwiched between two pieces of oak to form the skate of the plane and define the channel for the blade.  Cupping would result in a gap that was too wide, and a very poor overall fit and glueup.  After a bit of head-scratching, I hit upon a possible solution.  By ripping the board in half and regluing it, I could reduce the amount of bow in the piece considerably as shown above.  By doing this, I would have multiple contact points on both sides to register a hand plane for further flattening.  I couldn’t flatten completely, of course, as this would yield a board thinner than 1/4″.  Rather, I could form multiple flat areas on both sides and use epoxy to fill any gaps.

Grooving Plane 2
After ripping the piece down the middle and rejointing the edges, I glued it up and placed it in the clamps.  Conscious of the fact that I had two slightly cupped pieces of wood, I used a large number of clamps grouped tightly together.  This allowed me to use light pressure over a large area to ensure a good glue bond without excess pressure on the pieces.  To prevent buckling, I added F-clamps to the joint line in as many places as possible.

Grooving Plane 3
Once out of the clamps, I used my jointer plane (a jack would have worked as well) at an angle to level things out.  This approach allowed me to keep everything coplanar by registering off both edges of the piece as I planed.  If you look carefully, you can see the flat area forming on the near edge of the wood.  I ended up with one flat on each edge and one in the middle, with small gaps in between.  The opposite side had two flats, with small gaps at the edges and center.

Grooving Plane 4
I stopped frequently to check my progress.  I had already ripped the two body pieces from oak, and simply sandwiched the skate blank between them and measured the gap.  I stopped at 0.26″, figuring that I could fine-tune if needed with a few strokes later on.  This yielded plenty of flat area for gluing, and might even allow the use of hide glue instead of epoxy.  I’ll make that decision a little later on.

Next time, we’ll get into the shaping and fitting of the various parts of the two planes.  Stay tuned!


3 responses to “Grooving Planes Part 1 – Un-Cupping the Skate

  1. I thought exactly as you when I saw Matt Kenney’s planes: that’d be great in a 1/4″ version! I will be following with great interest. Thanks for blogging about it.

  2. thanks this is a great help!!!!!

  3. Pingback: Blanket Chest – Dimensioning the Stock | Little Good Pieces

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