Unless one want to embrace the inner yoga instructor, the garden bench needs legs. Time to rummage in the wood pile!
I’ve decided to build a base with three legs for the bench. Three legs will mirror the tapering in both width and thickness, and make the bench a bit lighter in appearance – and it will be easier lugging it around the property. It will be stable no matter where I place it because of the tripod effect.
I went to my pile of oak and got a nice piece of gash out from the stack.
This particular piece was in the process of becoming 8cm wide, 1.5” boards when something happened with the band saw sawmill. I cannot remember exactly what, but as you might see there is a cut line rising upwards from the bottom (look for the black streak on the left; the dark line starts just to the right near the bottom). The blade suddenly started to drift downwards, and since I did not have a very good line of sight to the blade – I did not notice it straight away. I backed off, corrected the issue and completed the cut successfully – but the damage was done. There aren’t enough material left on the thing to justify correcting the issue, so I tossed it aside to deal with later. And later is now.
A quick Sketchup session, and I had the general idea sketched out. A simple A-shaped frame connected to a T. The top rails will be countersunk into the log, then bolts secures the base to the slab top. The legs are all slanted 12 degrees, and I suspect the whole thing would be pretty stable. The tenons will be wedged and glued, and the bridle joints drawbored.
(I later decided against a rail on the single leg. It would not be a very strong joint unless the rail were made rather tall. That would not look right. I found a more elegant approach that worked out great.)
After a bit of measuring, thinking and planning, I cut the piece in two for further processing. No need to joint the whole thing; that would be a waste of materials. A quick job with my S&J 9500R, and dar she blows!
I jointed one side, cut the waste side away then squared off two sides to each other on the jointer.
The band saw made quick work of ripping the pieces roughly to size, then the thicknesser took care of the last bit of dimensioning.
The machine leaves tell-tale undulations in the surface. A quick once-over with the smoothing plane and the cabinet scraper, got rid of those.
In short order, the blanks for the base were made ready. 4S and good to go!
I decided to go with a 12 degree angle on the legs, as I had a 12 degree guide ready made from the side table project. I laid the parts on my bench top and secured the top rail with a holdfast. This enabled me to play around with the placement of the bottom rail.
I marked out for the bridle joints with my Veritas marking gauge, the width of the center portion corresponds with one of my chisels.
For the bridle joints in the legs, I made a knife wall, sawed down to the line, hogged out the bulk of the waste with a chisel, then used the router plane to get to final depth and to smooth the surface of the joint.
The finish left by the router plane is really smooth. The knife wall renders the edges crisp. No tearout or splinters.
Time for the top rail bridle joints. I started by making the mortises in the top rail, and they are made to fit the width of one of my chisels. I then marked the tenons based on the mortises, and used the back saw to cut the tenons. The router plane ensured that the tenons were perfect and that they fit the mortises like a glove.
A small trick: undercut the shoulders of your tenons. Keep away from all edges by a tiny amount, and pare out a small amount. I’m guessing 1-2 degrees max. Just thin slivers. This will make the fit snug, and you eliminate any high spots along the shoulder.
The cross rail between the legs goes into a mortise and tenon, which will be wedged, through the center of the lower rail on the A-frame. My Ashley Iles firmer chisels are a treat to use for mortising – cuts like butter and stands up to a bit of force. The thick profile aids to keep the chisel square to the mortise walls. The mortise was quick to cut in 3cm thick oak!
After doing some testing of the placement for the third leg, I grabbed the bench top to see how it will look.
I made the frame too wide on purpose; I wanted to see how it looked, and the thought was that a wide base would be more stable. While that is true, it just does not look right like this. Easy to fix, though.
I cut the dado for the top rail in the underside of the seat. This was quick and easy to do with the back saw. I used dividers to check that the height of the saw above the bench top was identical on both sides, which means that the bottom of the dado is parallell with the seat. I then chopped the waste with a chisel. After the bottom of the dado were dead flat, I created a slight hollow 80% of the width so that the top rail rests on two points at the extreme ends of the dado. The frame will be secured using one single bolt in the center, allowing for movement.Those two points ensure that there won’t be any racking when the seat moves. Which I am sure it will do.
As mentioned before, the frame was too wide. I measured the desired width of the top rail and extended the mortises accordingly. The lower rail was then fitted to the new width.
Time for glue and clamps!
I am going to secure the legs to the top using one bolt, and I did not want to drill the hole before I could determine the exact center of the top rail. Why care about something that NOBODY will ever notice? That bolt is going on the underside of a bench – who will see it?
Well, I do believe in training one self for perfection. So I measured the exact center of the top rail, used the forstner bit to mark the center of the hole (placed the point at the mark, then whacked the bit with a hammer) then drilled a hole the depth of the head of the forstner bit. Then I swapped for a regular spur point drill bit and drilled the hole all the way through. The head of the bolt is slightly lower than the surface of the rail. Perfect. The hole is big enough to fit a socket when the bolt is going in for real.
On the next page, I’ll fit the third leg and the cross rail. Then I’ll apply finish.