Well, I can put it off no longer. It’s time for the workbench base to be assembled. I just went back and checked my previous blog entries, and it has been about a month and a half that I have been milling a making all of the parts that make up the workbench base. I guess I am a little nervous about putting it all together. I have now put so much work into making all of the parts, that if something splits or breaks when I hammer in the drawbore pegs, it will be a lot of work to remake things.
I decided to start the assembly by joining the legs to the short stretchers, and I got everything ready to begin.
I made my drawbore pegs from 5/8″ oak dowel that I purchased at the hardware store. I picked through all of the available stock and made sure that I only bought dowel the had straight grain and no run out side to side. If the grain does not run the length of the peg it can break in the joint. I cut the 36″ dowels into 9″ lengths and tapered one end on a disk sander. On the other end of the peg, I created a very slight dome. I did this thinking that it would help ensure that the force of the mallet strikes would be transferred through the center of the pegs and reduce the possibility of breakage.
I test fit the 5/8″ pegs in the 5/8″ holes that I had drilled and found that they were very tight. So tight in fact, that they would have to be hammered into the holes even without an off-set drawbore joint. I chucked up the pegs into the drill press and lightly sanded them as they spun. I only took a little material off and then retested the fit. They were still tight, but much better than before.
I then took all 12 pegs and put them in the convection toaster oven at 225° F for an hour and a half to try and reduce the moisture content to 0% and shrink them a little. My wife just loves it when I manage to drag my woodworking into the kitchen. At least this wasn’t as bad as when I baked the ceramic paint onto the planes I restored last year. Once the pegs had cooled, I put them into a sealed Ziploc bag to prevent them absorbing any moisture from the air. My plan here was to reduce the diameter of the peg to make assembly a little easier. Once the peg is hammered in, it will absorb moisture from the glue and the wood of the legs and will swell back up, making joint tighter still.
I applied a liberal coat of glue to the tenons and to the walls of the mortises on both legs. I put the first joint together and got two pegs from the bag. I brushed a light coat of glue onto the peg and squirted a little glue into the drawbore hole. I crossed my fingers and hammered the peg in. So far, so good.
With the second leg laying flat, I lifted the joined stretcher and first leg and put the joint together.
Again, a light coat of glue on the peg and some more glue squirted in the hole.
Hammering it in while it was standing wasn’t very efficient, so I laid the assembly down and finished hammering the peg in.
I had no glue squeeze out where the stretchers meet the leg, but I did have some around the pegs. I cleaned this up with some damp paper towel. Next, I checked to make sure that the legs were parallel and square to the stretcher. I measured the width of the legs at the bottom and top and found that the legs were a little more than a 1/16th wider at the top. I used a bar clamp to pull the tops of the legs closer together. I tightened the clamp beyond where needed and then released it. I then re-measured the legs and repeated the clamping process until the legs were identical top and bottom, without the clamp.
I also checked that the stretcher was square to both legs. No problems there, all looked good. I set the assembly aside to dry.
Before I started adding the glue to the second leg assembly, I did a quick test fit. Good job I did. I looked at the drawbore holes with the joint assembled and wow, were they ever off-set. I don’t know how I managed this, but on this stretcher, I some how managed to drill the holes off-set by 3/16″ instead of 3/32″. This is going to be seriously tight. I took a rat-tail file and eased the hole in the tenon a little and also made them taper some. Even so, I was really concerned about what would happen when I put these pegs in. I reassembled the joint and tested the holes with my drawbore pins.
It’s better than it was, but this is going to be interesting. I had no choice but to go for it, so I applied the glue.
I put a light/medium coating of glue on the tenon and a heavy coat of glue on the mortise walls.
As the joint slid together, I checked to see if any glue was scrapping off the tenon that would cause squeeze out around the stretcher. I didn’t want any squeeze out here, so I wiped a little away before fully seating the tenon.
I brushed a light coat of glue onto the peg and hammered it in. And hammered, and hammered, and hammered a little more. It went in, but look at the below picture. You can see how much the peg deflected, the hole was perfectly square to the leg when drilled.
The second set of legs went together without breaking. I wiped the excess glue from the pegs, checked the legs for parallel and square, adjusted them with the clamps as before, and set them aside to dry.
After a few hours, I needed to trim off the excess pegs. I’ve been meaning to buy a flush cut saw for some time now and just haven’t done it. All I have is my Japanese pull saw, but its teeth have set on both sides and it will scratch up the surrounding wood if not used carefully. To avoid this, I protected the legs with some painters tape.
With the peg trimmed nearly flush, I used a block plane to finish leveling the surfaces.
Lastly, I went over the area with a little 220 grit sandpaper to remove any plane marks.
I trimmed, planed, and sanded the pegs on both sides of all four legs.
The next morning, I prepared to join the long stretchers to the two leg assemblies.
Before assembling the rest of the base, I took a photo of two of the pegs going through the mortise so you could see how the pegs are staggered to avoid hitting one another. These oven baked pegs fit nicely in the holes that are drilled for them.
I’ll skip ahead a little here, I don’t need to show gluing up each joint. I laid the first leg assembly down, applied the glue as before, and hammered in the glued pegs.
I added the second stretcher to the same leg assembly.
I then added the glue to both of the remaining mortises, painted the tenons with a light coat and stood everything upright on the benchtop. I had a little difficulty in sliding on the remaining leg assembly. It slid much more smoothly when dry than when coated in glue. I used a scrap block of wood to protect the legs, and persuaded (hammered) the joint to close. As before, I hammered the drawbore pegs in and wiped of the excess glue with damp paper towel.
I measured the width of the base along the long stretchers at both the top and bottom of the legs. Again I found that the tops of the legs were a little wider than the bottom. I needed to pull the tops together but didn’t have a long enough clamp, so I hooked two together and adjusted the legs as needed. I checked that the legs were square to the stretchers.
The last thing that I did before letting the whole assembly dry, was to measure the workbench base diagonally. If these two measurement are the same, then the whole base should be square. I was very happy to find that the diagonal measurements were identical. I mean right on, within 1/32″. I’m really glad that it was correct to begin with, because as beefy as these timbers are, I’m not sure that I could have adjusted them if I had needed to.
I left the whole base to dry for a couple of hours and took some more photos (’cause there haven’t been enough in this post already).
I used the painters tape again to protect the wood, and I sawed off all the pegs. I planed and sanded everything.
So… here it is. The workbench base in one piece.
I’m really happy with how this went. Nothing split and everything is square and as it should be.
In the next post, I’ll mill, cut, and fit all the boards for the bottom shelf.
Is it just me or are these posts getting longer and longer?
– Jonathan White