Patching my Broken Dovetails

Now that I have the workbench top assembled and flattened, I can turn my attention to fixing the dovetail pins that I broke during the glue-up.

I found a block of scrap sapele that I can use as the end-grain patch.

A leftover scrap of sapele.

A leftover scrap of sapele.

I needed a slice of end-grain that was about ¼” thick, so I set up a makeshift fence on the bandsaw and made the cut.

I set up a quick makeshift fence on the band saw to slice off a piece of end-grain sapele.

I set up a quick makeshift fence on the band saw to slice off a piece of end-grain sapele.

I cut the piece of end-grain into the shape of the pin.  At first, I tried just spitting it with a wide chisel, by the wood split jaggedly, the piece was ruined, and I had to start over.  This time, I used a scrap of sapele as a fence and cut the next piece to shape with my pull saw.

I used a second piece of scrap to guide the pull saw.

I used a second piece of scrap to guide the pull saw.

Every time I use this saw on sapele, I think that it is blunt and in need of replacement. However, when I used it to flush-trim the oak draw bore pegs is cut through them as though it were razor sharp.  It must be that the sapele is much tougher stuff.

I cut the piece a little oversize.

I cut the piece a little oversize.

I made a paper template of the shape of the pin by sticking a post-it-note over the recess and following the edge with a scalpel.  I was then able to make the end-grain patch the same size as my template.

I pared and sanded the dovetail patch until it matched the paper template.

I pared and sanded the dovetail patch until it matched the paper template.

One of the broken dovetail pins was fairly well recessed into the joint.  The other was quite shallow and I thought that I should deepen it so that I could make a stronger thicker patch.

I used a chisel and mallet to deepen the hole and then cleaned up the bottom with a small router.

I deepened the recess in between the dovetails to allow the patch to be a little thicker.

I deepened the recess in between the dovetails to allow the patch to be a little thicker.

Here it is once the hole was deepened and at a consistent depth:

After some chisel and router work, the pin is ready to be patched.

After some chisel and router work, the pin is ready to be patched.

I refined the shape of the patch and added a slight back bevel to ensure a snug fit.

Test fitting the patch.

Test fitting the patch.

I brushed some glue onto both surfaces and gently tapped the patches in (both ends of the bench needed patching).

A little glue and the patch is installed.

A little glue and the patch is installed.

I applied clamps and left it alone.

A clamp applied until the glue cures.

A clamp applied until the glue cures.

I wiped away the squeeze out.

I wiped away the squeeze out.

A couple of days later I got around to planing the breadboard ends flush with the sideboards.  There is no better tool for this sort of job than the trusty block plane.

With the clamp removed, its time to plane the patch flush.

With the clamp removed, its time to plane the patch flush.

A low cutting angle is better when cutting end-grain, so a low angle block plane is preferred.  Skewing the plane as you make each cut will also help to reduce the effective cutting angle.

I took a few passes from one side and then reversed the plane and took passes in the other direction.  I was doing this to prevent splitting the edge of the patch.

The block plane excels at flushing up two surfaces.

The block plane excels at flushing up two surfaces.

Slowly the patch started to come down to the level of the benchtop sides.

Nearly there.

Nearly there.

I got the patch and all of the end grain on the breadboard end down to the level of the benchtop side.

That's as close as I'm going to take it with the block plane.

That’s as close as I’m going to take it with the block plane.

For my last few passes, I switched to a No. 4 smoothing plane and it flushed the two surfaces up very well.  However, as you can see below I got some chatter and it left a surface that I will have to clean up with a very finely set plane.

The patch blended in nicely.

The patch blended in nicely.

I will wait to clean this up until the end of the build.  The benchtop is still sitting on saw horses and trying to plane the edge of the bench with it laying flat is hard.  I need to be able to get over the top of the plane and take a continuous smooth pass.  I will have to stand the benchtop on its side to do this and I will need a friend (or two) to help me move it.

I think I have successfully fixed/hidden my screw up.  I was really annoyed when I broke the pins, and thought that I had seriously messed up the benchtop.  This fix wasn’t too bad; a couple hours of extra work, but in the end, it looks fine.

Now I can move on to building the base.

About Jonathan

I am a woodworker and hand tool restorer / collector. I buy too many tools and don't build enough - I need help!
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5 Responses to Patching my Broken Dovetails

  1. You did a good job on it. I had to strain to see the joint line.

    • Jonathan says:

      Thanks Ralph,

      It came out better than I had hoped. These screw-ups sure are annoying when they happen, but I find that they do usually teach you something when you are forced to find a way to fix them.

      All the best,

      Jonathan

  2. gman3555 says:

    Nice save! Blended perfectly.

    Greg

    • Jonathan says:

      Thanks Greg,

      I was just reading your blog when I saw you comment here. It looks like your glue up went much better that mine. It looks great.

      All the best,

      Jonathan

      • gman3555 says:

        Thanks Jonathan. Putting wood together is always a crap shoot. Anything can, and will, go wrong. Most times we are lucky. On occasion we are not. It’s how we recover that can make the difference.

        Greg

I'd love to hear your thoughts, comments, or questions.