you know i love paring guides. this isn’t news if you’ve read any of my articles about sawing or chiseling basics. my view is simply this — if you pick up a tool and you’re not using a guide, you’re risking an imperfect result. if the result doesn’t matter (if you’re not cutting at the line or you’re going to change the dimension later with another tool), this is perfectly ok. but if this is a finished surface for a joint or that someone might see or touch, it doesn’t matter how good you are. i’m not perfect. nobody is. i might cut a hundred joints without making a mistake but eventually i will — and it’ll likely be far sooner than a hundred. i’ll slip and go off my line. i’ll angle the chisel slightly. i’ll chip something. a guide guarantees success. failure in my case almost always means burning the piece. i don’t do imperfect. marks of the maker? bullshit. i want perfection. and i’ll start over if there are gaps or any variation. that may not be how you get your enjoyment from woodworking but it’s certainly where i get mine. finished products that look like they were made by a master, despite not being anything even close to one.
and we can all get mastery-level results as long as we give up the notion of “freehand” as the ultimate goal. of course, this depends on where you place the goalposts in your shop. but if you’re aiming for the same result as me and you feel the same way about imperfect results in finished products, you’ve probably already been converted to the cause of guide-blocks for every cut and slice and i’m preaching to the choir. there is, however, a situation where those guides are a little strange to use that comes up rather often. there’s a solution, though. what’s the situation? mitered box sides. in fact, there are two solutions. but i think one of them is far, far easier to deal with than others.
a little note before we go on. you can cut accurate mitered box sides on an angled shooting-board without any of this. and you can do it on a tablesaw without the guides i’m talking about, either. but this is for those who want to do it in a more flexible, minimalist way without giving up the accuracy. a handtool process requiring no complex jigs or machines of any sort. though, if you like, you can make the guides on a machine. if you have a basic shooting-board, though, [like the one i detailed here that can be built in a couple of hours by anyone at any skill level], this is something you can do in ten minutes or less.
first, what’s the problem? well, let’s say your box is going to be 20cm tall from 12mm stock. you cut your guide block at a 45-degree angle and clamp it to the face of the board and move it across the board. but as you slide the chisel across the face of the board, you’re creating a huge cantilevered section of the chisel more than a centimeter from the already-flimsy edge of the guide block — the joys of pythagoras’ triangles is that the hypotenuse is longer than the board is thick. and this is how we’re showed to do this by all the teachers. and they say if you want a guide on the other side, just stick one there to get the other face. i think they’re looking at the problem from the wrong plane, though. let’s stop focusing on the faces and reference the edges of the board.
start by getting a scrap at least 8x as long but the same thickness as your box sides. cut it into four equal lengths (in this case, at least 3-5cm long but you can use as long as you like). now take those four pieces to your shooting-board. your standard shooting board with its 45-degree angled guide on it. shoot all four at 45. now here’s the trick. assemble those four into a flat edge. make sure they fit together with no gaps. none. if there are gaps here, go back and shoot them until there are no gaps. you don’t need to worry about chasing your tail. shorten them all a little and it makes no difference. if you do this with your box parts, you just end up making a smaller and smaller box but with these scraps the length is unimportant and you’re only aiming for a perfect 180. you can check it by sitting the whole thing taped together on anything you know is perfectly-flat. now you have accurate guides.
instead of using those guides to reference against the faces of your stock, though, all you need is one clamp — clamp them flush against the edges of the board you’re working at making a box-side. now instead of paring face-to-face, you’re doing it edge-to-edge and you have no flimsy edge. you’re pushing across the grain, which is a far easier cut to make. and you only have to go from the edge to the middle — this 20cm box is now only a 10cm piece and that’s something you’ve done many times before without having to worry about it, i suspect. the angle is unimportant. just reference the back of your sharp paring-chisel against the surface of your guide and gradually approach flush. when it’s there, move on to the next board. no guessing necessary and they’ll all come together perfectly — the four blocks you made function like 8 because it’s two straight-lines coming together to form a complete square.
anyway, that’s a very simple little improvement in your daily box-making workflow and it’s something i’ve been using for longer than i can remember but i’ve had people both comment on how difficult paring the miters of boxes without a dedicated miter-angle shooting-board is and seem surprised by my process for making it work so i thought at least a few of you might enjoy a different approach to a simple task from what’s usually showed in classes and videos. yes, the traditional way will work. this is just easier. a new tradition? perhaps. thanks for reading.