Work Bench Part 3 - Laying out the Joinery 

Legs01

This time I will be laying out the joinery for the base. There is a lot to lay out for the legs, including many mortise and tenon joints, a dovetail joint, as well as a mortise for the vise nut on the front leg. First I decided which leg would go where, and what sides were faces. The legs are at a sixteen degree angle to the top and the mortices are parallel to the side of the legs. The two legs for one side were clamped together and marked for the top of the legs, as well as the mortices for the stretchers (top). A line was also made where the top edge of the through mortices for the long stretcher will be, the base of the mortise will be marked later. The process was repeated with the other two legs.  After all four legs had matching marks, the lines were transferred around the legs and I prepared to mark the mortices. All the mortices are one and a half inches wide and the full height of the stretchers, through the five inch thick legs. They were all marked at once, using the gauge set up only once to mark them and was left that way until the shoulder tenons were marked. This keeps things accurate, instead of resetting the gauge all the time. It pays to have a couple of marking gauges. Also at this time, I picked which stretcher would go were, and marked the height of the mortice off the actual part, not a measurement. The top of the legs were then cut to the sixteen degree angle, and the mortices for the long stretcher was marked as well (above).

Legs02Legs04Legs05

While the legs were out, I decided to cut the leg mortices. I marked the centre of the mortice with my dividers and marked where the holes would be drilled. I use a bird cage awl to mark the centre of my holes (above left). This allows the bit to start easily, right where I want it. After all the mortices were marked in such a manner, I moved on to drilling out the waste with my new Irwin expansion bit (above right). It preformed very well, cutting through this tough Manitoba oak with ease. All the holes were drilled in from both sides, to aid in keeping the holes straight.

Legs03

Next the tenons were marked. The short stretchers were easy to mark, the length of them is the width I wanted the finished bench top to be, plus about three-thirty-second of an inch. I marked (left), and then cut them to twenty-three and eleven-sixteenths of an inch. I cut them as accurately as I could, but the ends won’t be planed at this stage. There is a bit extra that will stick out the ends, that will be planed flush to the leg later. Both legs for one side were then sat upon their respective stretchers. There was a little sticking over the ends, that will be planed later. They were then marked to be the final width apart with a marking knife, and the base of the tenon was marked on the top stretcher. This line was marked all around the board, and was transferred to the middle stretcher and the lower dovetailed stretcher, as the base line of the dovetail. The legs for the other side were done as well. The tenons were then marked with the gauge I used before, only having adjusted the fence for centre of each stretcher, not for the spacing of the two marking points. 

Legs07
Legs8

First the line for the top of the mortice for the long stretcher mortice was marked at sixteen degrees. Then the legs were laid on the ground, face up, in the positions they will be in (above). I placed the long stretcher on the top of the legs, and lined up the top with the line previously marked for the top of the mortice. The bottom of the mortices was marked right off the stretcher. The line for the approximate shoulder of the tenon was marked at this time as well as the long stretcher. I then laid out the mortice and tenon, and drilled the holes in the leg. To drill the holes at the angle with ease, I clamped the leg in a vise at sixteen degrees, and drilled at a ninety degree angle (right). 

Legs06

I further reduced the waste in the mortices with my bow saw (below). I have used my bow saw for quite some time now, and I find for some applications, the blades (and coping saw blades as well) are too thin for some tasks. For the past little while I have been using a blade that I made for my bow saw, using my Foley retoother. It is cut from .025”  thick spring steel at ten ppi, with about twelve degrees rake and about ten degrees fleam. It is quarter inch wide and twelve inches long. I cut two hardened steel pins to hold the blade in place, and drilled holes for them with a carbide drill bit. It cuts like a dream. After all the mortices were drilled, I cleaned them up with a chisel.

Tenon1

Next the tenons were all cut in the same manner. I started with the short stretchers for the legs, they were cut mostly with my large tenon saw, which was a bit too short, so it was finished up with my frame saw (left). The tenons for the long stretcher were cut with a Disston D8 filed to a ten degree rake, which did this rip cut well (below).

Tenon2

 The next step was to chisel out the mortices (below). I used my morticing and bevel edge chisels to remove the waste, with several trips to the sharpening stones, as this oak is very tough.

Mortice1

The mortice for the leg vise nut was laid out and cut at this time as well. It is cut  into the leg as a mortise, and will need holes for leg bolts that will attach the nut to the leg. First the placement of the screw was determined and marked. This gave the nut location. The nut needed to be mounted so that it will be tight to the vise back when it is installed. So I determined the thickness of the back and marked that as my line for the mortise and laid out the rest with my mortising gauge, square and my sliding bevel. After it was marked, it was drilled and chopped out to the proper depth (below).

Viseleg1Viseleg2










The dovetails were the last to be cut. First the stretchers were cut to their final length and then squared the ends up. The base line of the dove tails was determined previously, so the length was the base line plus the dove tail lengths.  I went with a bold sixteen degree angle, to match the leg angle. I cut the tails first (below left), in the usual manner, and they are big dovetails, so it is time to try to do the best saw cut your can. Happy with the results, it was time to transfer the tails on to the legs. I laid out the legs and placed the dove tail stretcher on top and lined up the shoulder with the edge of the leg, then clamped them together once they were lined up. The tail was then marked with a marking knife, and the half blind dove tail was cut. I cut as much as I could with a saw (below right), then the rest was drilled and chiseled out.

Dovetail2
Dovetail1


That is it for this time, its has been some time from my last post till now, but I hope to have more time now to get some work done on this site. Next time I will glue the base together, as well as give it a first assembly. Till next time.

© Shane Larson 2017