-- $160, 4 hour glulam workbench build -- part 2
whoa! those legs go like... all the way down to the ground...
The first thing we concentrated on were the legs. We took the rough lumber and picked out the clearest portions. We got three legs out of one 4x4 and with a lot left over in the second. Now it's time to hit the current bench. If you don't have one yet, don't fret! Stick the glulam on a couple saw benches, or chairs or whatnot. You don't really need one to accomplish this project.
Here's my first bit of advice. When you are marking multiple items the same, or sawing items to be identical, gang as many together as possible and do them all at once. This serves many things.
- It makes sure you're marks are all the same. I know I make mistakes. I guarantee I make mistakes. By marking all four legs at once at least I know the mistakes are consistent. If I'm off a quarter inch... who cares, they'll all be off identically and it won't matter.
- It is easier to check angles the longer the distance because errors are multiplied the farther out you go. When I did these 90* markings I simple reversed the square and made the mark from the other side. Since I didn't see two lines the entire length I knew I was dead on but if I did... the farther out you go the greater the distance between the lines. To correct the mark simply make a mark in the center of those two to get 90*. (see animation)
- It's easier to saw a straight line if you are sawing a longer distance.
This first line marked across all the legs is the absolute most important mark of the legs. It is your reference line. Leg length and tenon length are determined based upon this line. So of all your marks, this one has to be right. Place all the legs on your workbench and choose which side will be the face (show side). I will mark this face on each leg for easy reference.
Because I'm lazy, at this point in time I am not concerned with tenon length. Just leave more than enough space from the end to accomplish the task of being a tenon.
Now that the face is marked a perfect 90* it is time to mark the shoulder all the way around. The sides do not have to be perfect 90* so if you're square is off a degree or two, don't sweat it. Just be sure that the angle goes in the same direction both sides.
Now here is where you need to do some thinking. What temperature is the bench top. Is it hotter than the average temperature it'll normally be? What I mean is will it'll eventually reside in your 80* air conditioned workshop but you are assembling it outside on a 108* day in Texas. If so then use your squares inaccuracy to your advantage. The tabletop will shrink in width a little bit as it gets accustomed to your cooler shop. So if your square is off a degree then have the side mark angle so that the legs will angle in slightly. In this manner the legs will start out shorter than the width but will flare out a little as it shrinks since the stretchers won't shrink in length. If you are assembling it in winter, do the opposite.
Do not use your square for the back, your squares inaccuracy will cause the line not to connect and you'll get really mad, erase all the lines and start over, then do it again because you got the same result, erase... frustrate... erase... then realize that you're an idiot. Just use a straight edge to connect the two lines on back. When you are done you'll have opposite sides in-line, the front and back will be at 90 and the sides will be the same degree off of you square.
Next up, mark the tenons. DO NOT MEASURE THESE WITH A RULER! If you're like me you'll screw it up. Just use whatever chisel you'll be using to cut the mortises. I have a 1.5" chisel so that is the size my tenons probably are.
Now there are several was of doing this. I'm using a mortising gauge but if you don't have one just cut a scrap stick to an inch or so. Then use that as a shim to measure a consistent distance from the reference edge (face). Place your mortising chisel against that and mark both sides with a pencil. If you use the same shim on all legs and on the bottom of the table top everything will work out fine.
If you are using a mortising gauge then set it to the width of your mortising chisel. Set the distance from the edge so the tenon will be somewhat in the middle. You don't have to be too worried about exact measurements from the edge because we won't change these settings for the entire project.
Now here it's important that you always mark from the face side (register side). If you marked the face at the beginning then it should be easy. If you didn't... have fun and remember to next time.
I wait to mark the sides until after the face and back are cut off. It means you get to cut less wood and these measurements aren't too important.
Lets cut some tenons! I'm not going to tell you what the best tool is to do this. There is no reason why you couldn't do this with a coping saw or a 26" handsaw. The wood doesn't care. Technically we should use a tenon saw because... well it "is" called a tenon saw. But I don't have one of those. So in this example I'm using my carcass saw. It wasn't quite long enough so I finished the cut with a Japanese saw which didn't have a back. Dad on the other hand looked over at his band saw...
Also, since we didn't have a bench yet I'm using this trick with two screw clamps I saw in some magazine. Sorry for not being able to tell you what magazine or episode, I couldn't find the article. Simply lay one clamp on it's side and use the other to secure it to the table.
Position the leg in the vise so that you can pinch the edge with your fingers and use them as a fence for the saw to start your cut. I typically will advance the cut across the top and then come down the side facing me. In that manner I get to watch each line individually as I cut it. I then reverse the leg in the clamp and repeat down the other side. This'll leave a triangle in the middle that you power thru because both sides will guide it straight. Don't worry about what your cut looks like, it won't show.
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On the other hand the face cuts will, so if you are concerned about how your joint looks take a few minutes to make a knife wall for the saw to slide into. Use a marking knife and straight edge and mark your pencil line with a few light passes. Then use a chisel to cut the tenon side edge out. Rinse and repeat a few times. This will give you a really straight show line without any chip out from your saw.
Since this is just a workbench I wasn't worried about the joint being cosmetically perfect so we just sawed to the line. When both front and back tenon's fell off I simply connected them to cut the sides.
Now cutting the sides of the tenons, so that you have a reference face all the way around the leg, doesn't need to be exact. Pick a distance, mark a line, saw it off. In my example I used an extra gauge I had, remember we don't mess with the mortising gauge once it's set, to about an inch.
Please note I have NOT cut the legs to length yet. Why? Well... remember me being lazy... Before we can move on to mortising the top for these tenon's we need to identify which leg goes where. So pick your two best looking ones for the front and label them all. (I use A-D)
The next phase of this project is cutting the mortises in the bottom of the table top.