A few weeks ago, I got started on this bookshelf. I started with cutting some mortises, which are the slots or holes in one piece of wood for tenons, which are the tabs or jutting-out-bits on another piece of wood. By checking out those two posts, you get a sense of what’s involved in making this bookshelf. What with one thing and another, it’s been very hard to get back to it, but today I had some time between errands, so I put in a few hours on it. I made quite a bit of progress today!
First off, I cut the next six mortises. I did this by drilling out the corners of the mortises, and then using a coping saw to cut out the waste. This was MUCH easier, by far, than chopping out most of the waste with a Forstner bit and then trying to carve the corners true with a chisel. Once the waste blocks were cut out it was much easier to true the corners with a chisel and be done with it. In some ways they’re not very elegant, but they’ll definitely work — and better yet, I know how to do it more effectively next time.
As you can see from this image, the process of truing up the corners of a mortise is a bit of an effort. You want the tenons — that is, the tabs on the shelf board — to slide into the mortises easily, and with a good fit; but you don’t want them to be either fussily tight, or so loose that the shelf wobbles. The mortises at the top and bottom of the board were the best fits; the tenons at the top slid right into the mortises, no problem. There was one chunk in the bottom mortise at the front that I needed to clear with a chisel; the middle two mortises for the middle shelf required the most work.
Coping
I saved a couple of my own photographs of this coping saw process, as you can see. The drill holes are relatively small; and make sanding off the corners of the shelf tenons less immediate of a problem. Since the corners of the mortises are rounded, it’s possible to avoid going to a lot of trouble to sand the tenons to match the precise square holes.
The coping saw blade angle has to be adjusted for each cut. You also have to be careful not to be too vigorous with the saw. You want your cuts to be straight up-and-down, to avoid too much chisel work — because chisels are accidents waiting to happen — but the blade on a coping saw wants to make a weird curved cut if it can. Don’t let it.
Sharpening
A word about Chisels being accidents waiting to happen. Whenever I have injured myself in the carpentry studio, it’s been with a chisel. Whenever I’ve injured myself with a chisel, it’s been a bad cut. Whenever it’s a bad cut — it’s ALWAYS been because the chisel wasn’t sharp enough, and I was trying to force a cut to happen that should have been easy.
So have sharpening tools in your studio. Have a workspace set up specifically for sharpening tools. Teach people to sharpen their tools properly. They will have more respect for sharpened tools that they sharpened themselves, than for tools you sharpen for them. Also, they will know how to do it, and you will not be a cutler at the grinding wheel all the time while they get to do all the fun work.
Mortises & Wedges
Now that I’ve cut mortises and fit all the tenons, my next task is to cut a new set of mortises, smaller ones about 3/4″ square, into each of the twelve tenons, and to make wedges for these smaller mortises. The wedges and mortises will help hold the shelf together without nails and without fasteners, which I like. Getting these cut out should be easier now that I have a process for them— but the temptation is to drill them out with a 3/4″ Forstner bit, and then true up the corners into a square. See notes above under Coping — don’t do that, Andrew.
For the MakerSpace
Why build a shelf as the next thing after a the work of making a pair of saw benches and worktables, and a couple of boards for tools? Or what about a serious workbench where I can get really seriously down to business?Why not get started on making stuff I want to make?
Well, yes, I’m doing that ,too. The Yarn Winder, for one, and the Yarn Swift. Those were fun. And I’ll get to the workbench eventually. But (and this is important), there’s an important component of any MakerSpace, whether it’s a specialized workspace like Beehive Sewing (that only does textile work) or somewhere else that’s more generalized like a school Design Lab. It’s actually much more important than any of the physical pieces of hardware or tooling that your MakerSpace can have, and everyone forgets how important it is.
But that’s a secret. For now.
[…] this process — each time you make a hat or a coat or a cheese or a tool chest or a book or a bookshelf — you’ll discover that you have a new set of tools for solving problems and building and […]
The coping saw is a fine choice for pine. I wonder if you would feel the same about oak or maple. One of the the advantages of hard wood, is the tightness of the grain. A good sharp chisel, hit well with a mallet, slicing through grain cleanly is a beautiful experience. And the quality of wood makes the piece, if not heirloom, significantly more durable. And then, if you need wedges for those mortise and tenon joints, I do have a bit of walnut which makes a nice contrast.
All of that sounds good. This was intended mostly as an experiment, to learn how to do it and to make a shelf for my reference books for the woodshop; so investing in high quality wood for it seemed… excessive. I’ll take your word for it on chiseling through hardwood. At the moment I don’t feel I can afford the investment in hardwood.