The Workbench Build Resumes

It has been nearly a month since I posted anything about my “Ambidextrous Grizz-ubo” workbench build.  Frankly, there hasn’t been much to post as progress has been next to none.  I have been fanatically watching all the World Cup matches and the little time that I did spend in the shop was spent restoring some recent old tool acquisitions. When I left off last month, I had cut tongues on the ends of my workbench top and fitted bread board ends.  I had also cut the tails portion of the dovetails that will hold the sides of the benchtop to the bread board ends.  The next step, is to transfer the dovetail layout to the bread board ends and cut the half blind pins. I fitted the breadboard ends onto the benchtop and then clamped the side boards (with the tails on them) in place.  I was happy to see that the shoulders of the tails lined up perfectly with the breadboard ends.  Using a marking knife I traced around the tails and marked the end grain of the breadboard ends.

The tails were clamped in place to transfer the layout lines for the pins.

The tails were clamped in place to transfer the layout lines for the pins.

I used the in-expensive marking knife that Lee Valley Veritas sells and it worked great. Although, with tails 6/4 thick, I was about at the limits of the knife.

Transferring the layout lines with a marking knife.

Transferring the layout lines with a marking knife.

With the tails transferred to the pins, I un-clamped everything and took the breadboard ends off the bench.

Here you can see the layout lines.

Here you can see the layout lines.

I needed to saw the half-blind pins, but I don’t have a workbench… Or do I?  I clamped the breadboard end to the edge of the workbench top.  Even though the benchtop is only sitting on saw horses, this top is so massive that it really immobilizes the work-piece and doesn’t shake or move at all.

I clamped the end vertically to saw the pins.

I clamped the end vertically to saw the pins.

I started to saw to the lines.

I started to saw to the lines.

I went slowly, and very carefully tried to stay within the layout lines.  When I was sawing the tails, I also tried to closely follow my layout lines, but I knew that if I strayed from them a little it wouldn’t matter.  However, now that the tails are cut, the pins must be cut with greater care or the joint will either be too loose or too tight.

I found this a little tricky.

I found this a little tricky.

Trying to stay within the layout lines.

Trying to stay within the layout lines.

With the lines sawed as deep a I can without crossing the layout line, it was time to switch my saw for a mallet and chisel to remove the waste.  Since I have so much waste to remove, I thought that I would drill out some of the waste the make the chisel work a little easier.

I drilled out some of the waste and chiseled the rest.

I drilled out some of the waste and chiseled the rest.

Here’s what I ended up with:

The first end finished.

The first end finished.

And so my first major design flaw is revealed.  When I was gluing up the breadboard ends, I should have made the pieces that filled the gap in the breadboard ends longer. This would have meant that the tongue on the ends of the benchtop would have had to be trimmed down so that it was not as wide, but it would have left some material behind the center pin for some support.  Oh well, you live an learn.  Still, I think that I can make this work. Speaking of trimming down the tongue, I took about half an inch off each side of the tongue so that the tongue did not entirely fill the dado in the breadboard end.

I trimmed about a 1/2" of the width of the tongues.

I trimmed about a 1/2″ of the width of the tongues.

This should give me a little wiggle room for error.

This should give me a little wiggle room for error.

One down, three more to go.  This took a little while.  As I chiseled the pins on each end, I tested them to ensure a proper fit with the corresponding tails. Once they were all done, I put the breadboard ends back on the bench.

With the pins cut, the breadboard ends are finished.

With the pins cut, the breadboard ends are finished.

I sure hope I don't snap off that center pin during the assembly and glue-up.

I sure hope I don’t snap off that center pin during the assembly and glue-up.

 

Your help and opinion needed here:

Before I glue on the sideboards and complete the workbench top, I think that I should draw-bore the breadboard ends onto the benchtop.  Since they are a cross-grain joint, I am not going to glue the breadboard ends onto the benchtop.  As it stands now, the only thing that will hold them in place is the dovetails on either end.  I think that I should add a draw-bore peg in the middle of the breadboard end.  However, the center sapele “stringer” in the bench is a lamination and I don’t think that it would be a good idea to put a draw-bore peg right through the stringer.  I think it wont be strong enough and the wood will fail when I hammer in the peg.  I also don’t want a single peg that is not centered as I don’t think that it will look right.  What about two draw-bore pegs, one either side of the stringer?  I cut two half inch circles of blue painters tape to represent the peg locations.  If I use two pegs, the cross-gain wood in between them is completely immobilized, so I figure that they need to be close enough together that any wood movement between them is insignificant, but far enough apart that I don’t split out the sapele when I hammer in the pegs. What do you think?  Do the planned peg locations in the below pictures look like they will work?

Possible locations for draw-bore pegs marked with painters tape.

Possible locations for draw-bore pegs marked with painters tape.

A single draw-bore peg in line with the center stringer, or a double peg like this on either side?

A single draw-bore peg in line with the center stringer, or a double peg like this on either side?

While  had the breadboard ends dry fitted, I pushed one of the sideboards gently into the pins and everything lined up perfectly.  The remaining glue up shouldn’t be too difficult.

The side board is lightly pressed into the pins to test the fit.

The side board is lightly pressed into the pins to test the fit.

I’m almost done with the top and I’ll be glad to move onto the legs and stretchers.  Let me know what you think about the draw-bore pegs.

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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4 Responses to The Workbench Build Resumes

  1. Jonathan, my only concern with using a classical draw-boring technique (offsetting the peg holes so as to achieve maximum tightness) would be that the resulting joint might result in a slight decrease in your shoulder-to-shoulder allowance for the side pieces. Remember that you laid out the tail sockets before fully securing the end pieces, so if you draw-bore the ends for maximum tightness, you may shorten the distance the side pieces can span, and lose your perfect fit. You might consider simply boring and pegging the ends after you have completely assembled all four parts. I would also question whether driving home 1/2″ pegs into that rather short tongue might not risk splitting it, even if you use untapered pegs. What would you think about using perhaps four smaller diameter dowels, evenly distributed across the tongue? Larry

    Good luck with the layout on the remaining three, BTW.

    • Jonathan says:

      Hello Larry,

      Thanks for your comments. You raised some really interesting points that are making me rethink my approach for the next step. When I laid out the dovetails, I made sure that the breadboard ends were snug up against the shoulder of the tongue, but I had not given any consideration to the end grain shoulders of the doug fir being compressed by the draw-bore pegs. After thinking about your idea to just peg the joint after assembly, I thought that if I do draw-bore the ends I should only use a small off-set, perhaps no more than 1/16th of an inch? Maybe even a little less. This should keep it snug without being so tight that it affects the dovetail fit. Also, you are right about the tongue being relatively short. That said, it is nearly 2″ thick, so I think that there should be some strength there. I think that I will have to use only a very small off-set in the draw-bore holes and it should minimize the stresses.

      I thought about your idea for four evenly spaced smaller dowels, but wouldn’t that be the same a gluing the end on? It would lock the cross-grain joint together and not allow for any movement. Either that, or I would have to elongate the holes in the tongue. Thats a possibility.

      Thank you very much for your thoughts. This is exactly what I was looking for. Sometimes you just need to bounce ideas off someone, or have them pick your ideas apart to help you find the deficiencies. I really appreciate you taking the time to comment.

      All the best,

      Jonathan

      • Jonathan, I understand your point about restricting lateral movement of the tongue with four dowels,, and elongating four holes, each of which has also been offset for draw-boring, could cause some unforseen problems in getting the ends of the edge piece flush with the edges of the bench top when hammering the pegs, I agree that if you’re conservative with your hole offset distance, you should be okay. If you do want to draw-bore, yes I would go with only two pegs, but perhaps centering each peg on each half of the benchtop would better equalize the pressure across the length of the joint. Also, you might consider assembling the first end cap, dry-fitting/clamping your two side pieces to it and the top, and then hammering the pegs (at least partially) home…..before you do your layout on the other end. That way, you’d only have to be concerned with 50% of the shoulder-to-shoulder issue I described. I would think you’d be able to pry your dry-fit tails out of their sockets with a broad drywall knife, after you’ve finished the layout on the other end Regards, Larry

  2. Pingback: Draw Boring the Breadboard Ends. | The Bench Blog

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