Top Alignment Dowels

2009.12.09

As I have said before, I have been designing and building the workbench in such a way as to allow it to be disassembled in the future.  So the top will not be permanently attached to the legs.  To hold the front section of the top in place, I will be using a couple loose dowels.  As much as I’d like to rive some more oak and make my own dowels, there’s no way I can make a 3/4″ hole in the steel dowel plate.  So I am using purchased dowel stock.  The dowel stock was a little undersized, and my 3/4″ auger bit is a little oversized.  So, I decided to use my 11/16″ auger bit, and then sand the dowels down to fit.  I made a drilling guide to help me align the holes in the top of the leg and the underside of the top.

Hand sanding the dowels down to 11/16″ or so was tedious.  Not to mention dusty.  But finally I had a good snug fit.  So snug in fact that I had to use vise grips to pull one of the dowels out.

After testing each dowel in the two mating holes, I put them in place and brought the top down, hoping all the holes were in the right places.  Wow, everything lined up (with a little wiggling and light pounding with my fist).  The front face of the top overhangs the legs a little bit, so I’ll need to plane that down.

Planing the Front Edge of the Top

Time to open the box of my Veritas bevel-up jointer plane.  I took a few passes along the front edge of the top.  The top and legs still aren’t totally flush all the way across, but probably close enough.  As long as the top is proud rather than the leg, that’s all that should matter for clamping in the vise.

2012.12.06

Although for a while I tried sliding dovetails, I went back to these two dowels to hold the top in place.  This works fine, except for two issues.  One, with changes in humidity, the front edge of the workbench top has moved out of alignment with the front face of the leg.  It’s not a total disaster, but less than ideal.  Two, when I clamp something in the vise that is no deeper than the thickness of the top, the clamping pressure makes the dowel creak and groan and pushes the workbench top back… also creating the front face alignment problem.

If I ever build another workbench (egads), I will probably use the sliding dovetail tenon shown in Roubo’s illustrations, and detailed in Chris Schwarz’s book.  This locks the front of the top and legs together so they move as one.  Without glue, it could theoretically be knocked apart for transport if needed.