The Saw Bench
The Lumber
As with any other project, the saw bench first starts out as a pile of rough lumber. In this case, a leftover length of hem-fir 2 x 10, a leftover length of 2 x 2 poplar from the home center and an old poplar 1-1/4" closet pole. I tend to try not to spend a lot of money on shop projects, preferring to just use whatever lumber I have on hand. Shop appliances are typically utilitarian in nature and will get nicked, dented, cut, gouged, scratched, knocked over, stood on, and have all sorts of finishes, solvents and glues splattered and stuck to them. Therefore, I prefer to use whatever lumber I already have left over from other jobs and I don't build them overly complicated or elaborate as they are likely to need replacement at some point in the future just from normal shop use.
Size & Layout the Bench
Begin by working on the bench top as all of the legs will anchor here, just like in a Windsor chair. Cut the top to the desired length and assess it's flatness. I'm working with construction grade stuff that was sopping wet when I bought it and has since dried thoroughly in my climate controlled shop. The result of this is that my 2 x 10 had a serious cup to it. Rather than plane the cup out, I ripped 2" off one side. This left me much less cup to plane out, saving thickness in the final top. This had the added benefit of removing the huge knots along the edge that can be seen in the first picture, one of the problems with working with cheap lumber.
All layout and boring of the legs is done from the bottom of the benchtop. I located the center points for the legs about 6" from the end and about 1-1/2-2" from the edge. I used two angles to lay out the splay of the legs. The first angle was obtained by laying out an equilateral triangle with the center points of the legs at two of the corners, as seen in the picture. This provided for a 60 degree angle to the sides of the top. I'll bore my holes for the legs along these sight lines. The second angle, shown by the bevel, is a 1:3 rake angle that I will use to guide the angle of the bit while boring.
Bore the Leg Holes
I'm using a #16 auger bit, which has a diameter of 1", to bore the leg holes. I find that the easiest way to bore holes of this size is to be able to get over top of the piece. The workbench is just too high for this unless you climb on top of it. Here, I'm sitting on my old saw bench, the one that will be replaced with this new one. You can use a picnic bench, a couple of logs, climb on top of your workbench, the back of your shave horse (if you have one), or even just prop the board up on a couple of 2 Xs and kneel on top of it on the floor. Whatever lets you get over top of the brace. In this picture you can see that I place my chin over the brace pad so that I can sight down the bit as I bore in order to bore at the correct angle. I stop every few turns of the brace and re-check the angle with the bevel, correcting the angle with the next couple turns if I'm off at all. Don't stress over this though, the angles don't need to be perfect and they don't even need to match.
Taper the Mortises
This next step is completely optional so don't worry of you don't have a taper reamer. I made mine previously to use building my shave horse and for use making chairs later but if you don't have one, you can keep your leg mortises un-tapered. My current saw bench has un-tapered holes and has served me just fine for years. If you do choose to taper your mortises, be sure to ream at the same angle that you bored with the brace and bit. It's not critical that all of the leg angles match but it makes for a nicer finished product. It's also just a good habit to get in and good practice for future furniture projects, like chairs, where it really counts. Again, use the bevel to gauge your angle and ream only until the reamer begins to contact the perimiter of the hole on the exit side. There's no need to ream further than that.
Layout the Legs
With the bench surface done, it's time to move on to the legs. Begin by cutting the legs over sized. The length of 2 x 2 poplar I had was 8 feet so I just cut it up into four 24" sections. The extra length will be necessary later to allow for leveling of the bench. After cutting to rough length, lay out an octagon on the end of one leg blank. Begin by finding the center by drawing diagonals. Next, take a pair of dividers and set them to a distance equal to half of the length of a diagonal. Swing two arcs from each of the four corners. Finally, connect the marks to make an octagon. Using these marks, set a marking gauge to scribe the corners of the octagon along all four sides of all four leg blanks.
Shape the Legs
With the octagon laid out on the legs, begin shaping the legs. I did this on the shave horse with a draw knife. My shave horse has a "V" notch in the clamping head that allows it to hold stock on edge making it easy to shape square stock to an octagon. If you don't have a shave horse, holding the leg blank in your bench vise will work as well, you will just need to work at an angle. You can also plane the blanks to an octagon if you do not have a draw knife by putting the blanks in a pair of "V" blocks and planing off the corners. After rough shaping with the draw knife, smooth and bring the legs to the scribe lines with a spokeshave. If you used a plane to shape your legs, this last step likely won't be necessary.
Shave the Tenons
I chose to leave my legs as octagons but you could certainly shave them round if you like. I did this on my shave horse. To begin shaping the tenons, lay out a 1" circle approximately centered on the end of each leg. Begin shaving the tenons with the draw knife, making a very short tapered tenon by shaving almost to the circle. Switch to the spokeshave to lengthen the tenon and begin to fit the taper. Take your time and try the fit in the bench often. As you get closer, twist the leg in the bench, remove it and look for the contact points which will be shown as shiny burnished spots. Shave the shiny spots away and test fit again. You are done when the tenon projects slightly through the top of the bench and the leg fits snugly in the bench. Finally, dry fit all four legs to the bench. Prop the bench up on some scrap 2X material since the tops of the legs will come through the bench surface.
Make Stretchers
I decided to add an "H" stretcher to the bench but you don't really need one if you don't want to add one. My current saw bench doesn't have one and the shave horse doesn't have one either and they are perfectly fine. Start by measuring up from the benchtop about 15" and make a mark on each leg. Set a bevel to connect these marks. This is the angle to bore the legs at. Bore a 9/16" hole for the stretchers. Use the bevel to check as you bore. Put the legs back into the bench and mark the shoulder to shoulder length on the stretcher stock. Add the length of the tenons to the stock and cut the stretchers to length. Mark the 9/16" tenon on the ends and drawknife, spokeshave and test fit the tenons on the stretchers. My stretchers ended up different lengths as my leg angles were not identical. No big deal. The long center stretcher is done the same way except that the end stretchers can be bored at 90 degrees since they are parallel. Finally, dry fit the assembly and make any necessary adjustments before tackling the glue-up.
Assemble and Trim
Begin assembly with the stretchers. Glue the center stretcher into the end stretchers using liquid hide glue. The liquid hide glue sets slowly to allow adjustments to be made before the glue sets up. Tap the center stretcher into the end stretchers to firmly seat the tenons. Then glue the end stretchers into the legs, again tapping the joint with a mallet to fully seat the joint. Finally, glue the under carriage into the bench top, seat the entire assembly firmly and make any alignment adjustments before giving the bottoms of the legs of few final firm whacks to drive the legs home and set the under carriage in place. Don't hit the bottoms of the legs too hard or you risk splitting the bench top. Good fitting joinery doesn't need to be forced. Finally, set the bench aside until the glue dries. No clamps are necessary. After the glue has dried, trim the ends of the tenons protruding from the top of the bench with a back saw and flush them up with a block plane. Place the bench upside down on your bench top to mark the final leg length. I use a pencil with a flat sanded into one side to do the marking.
Mark and Trim the Legs
To mark the final length of the legs, cut a scrap stick to the desired height of the saw bench. I wanted mine the same height as my shave horse so I could use them as a pair of saw benches for sawing long stock so I cut my stick the same height as my saw bench. Use the stick to transfer the height to the legs by referencing the stick off of the workbench top and holding the flat of the sanded pencil flat on the top of the stick. Draw around the leg as far as you can reach with the pencil on top of the stick and the stick resting on the workbench. Mark all four legs referencing from the workbench and then saw the legs off following the angles drawn. After the legs are sawn to length, I chamfer the ends with a cabinet file to protect the edges of the legs from chipping. Finally, clean up the bench by planing, scraping and/or sanding if you like. I don't put any finish on mine as the raw wood surface has a little grip to it that I like.
