This article has it all! Biscuits, Joints, and a Pictorial. Almost everything one needs for a satisfying evening, almost. The hardcore woodworkers may whine and squeal that doweling a joint is better, faster, stronger, cheaper, etc…and there is something to that, I’m not going to get into that in this article. But–since I have a new tool, and a need to make some mitered joints–I went with a biscuit joint. It allows for some fiddling around with your alignment as the biscuit joiner will oversize the slot for the biscuit a bit allowing you to line up the joint. Be advised: a biscuit joiner isn’t exactly cheap–but if you are into Home Improvement/furniture/woodworking for the long haul: you would definitely put this tool on your wish list.
Ok–I can’t help myself: Biscuit joints vs. Doweling quickly summarized: Biscuits: More play, faster, more expensive tools, better pull-apart strength. Dowels: Has to be dead-on, easier dry-fit before glue up, cheaper tools, better shear strength. I’ll let the real furniture/woodworking guys debate the merits of either joint. I’m merely a carpenter, and there won’t be much–if any stress on my joints so a biscuit will work just fine. So–with out further muddying the waters: The pictorial, and brief description of my 45 degree miter joint. Would work good for building a picture frame, window, trim set up–just about anything you want to miter.
Biscuits are merely pressed wood in the shape of little footballs. (American footballs to our International crowd. Shhh about the World Cup. My wife recorded them as I try to maintain my sports bubble until I get back to civilization). They come in different sizes, and your biscuit joiner should have a size selection knob such as the one in the photo.
I chose to use a #10 biscuit for my example. So–turn the knob to the correct biscuit size, and the next step is to figure out the center of your stock (lumber, material). I was using 3/4” Pine lumber, so half of that is 3/8” of an inch. I set my biscuit joiner using the dial to 3/8”. This will place the center of the tool’s blade at that measurement. Coincidentally–this seems to be a pretty common size stock as my joiner sat perfectly flat on my worktable at this depth. The shoe of the tool will now hold my stock at a 90 from the blade opening. The blade looks like a tiny skill saw blade.
You will want to make sure your marks are on both pieces of stock to be joined. When you’re satisfied–go ahead and take the plunge. I start my joiner by pulling the trigger and letting it get to full speed before moving the handle toward my stock. One of the nice things about this tool is that it is pretty safe. There isn’t (and shouldn’t be) any blade exposed, and the possibility of flying debris is pretty minimal. Still: use all the regular stuff. Eyes and ears people. Making a habit of good safety allows you to feel confident when learning new techniques.
Once you have your slot cut–it’s time for glue up. For wood glue–I prefer Titebond. I like the initial tackiness of it, it dries a pretty neutral color, and it’s just what I’ve used. It works good. By all means use your favorite wood glue and go to town.
Since you used your joiner on both pieces of stock to be joined–glue up both of them on the joint. Make sure and get some glue into the slot you cut for your biscuit. It’s not going to do you much good to sit in there loose. Before gluing–you can dry fit it–but as I mentioned, a doweled joint will make for a more accurate dry-fit, so it’s not something that is entirely necessary here. Of course you essentially dry fit it as you measured and marked for your biscuit slot so at this point all it will cost you is time.
The next step can be a bit tricky. You’re going to clamp the joint. The joint itself doesn’t exactly need pressure on opposite ends–but that is optimum. You can do it like I did, but you need to have a small enough work table that the size clamps you will need will fit. You’ll notice that I used my JackClamps for this one–the small level vials are nice for this–but don’t get married to the idea of level and plumb when clamping. Your floor or bench could be a bit out–it’s more important that the joint is flat. Also–try and wipe off the excess glue you may have. You might notice I have indeed glued a finish joint to the table I was working on. I did not enjoy having to chisel it off messing up my bench, and my finish joint. I had to do it over. Not cool.
All in all–biscuit joinery is pretty simple and effective. I wish I could say that most mass produced furniture is done this way–but not likely. Mastering this technique, and using it–you could indeed build something that looks nicer, is cheaper to build (sans your time of course), and is stronger than something you can buy off the show floor. Plus–I just like working with wood and learning new things.