Using a Biscuit Joiner
George VondriskaDescription
Biscuit joiners are great for when you want to securely fasten a butt joint on your woodworking projects. George Vondriska teaches you how to use the biscuit joiner to attach a shelf at a 90-degree angle to the face of another board. A WoodWorkers Guild of America (WWGOA) original video.
I've got this bathroom cabinet I've been workin' on and I need to attach this little towel rack component to the bottom of it. It's a great application for biscuit joinery. And it's an opportunity for me to show you a couple of different ways you can use a biscuit joiner, make sure you understand the two different applications. It boils down to registering from the top or registering from the bottom. In this case, I'm gonna register from the top of this piece. What I wanna do is get this part fastened here just like this. Great choice for biscuit joiners because I basically got just a butt joint here, and I wanna reinforce that joint with the biscuits. Plus the biscuits will give me good registration to make sure these parts stay in alignment. So the first step is easy. All I need to do is get my part held on here. And I'm gonna lay out for three biscuit slots. One of the things I really like about biscuit joinery is that you don't have to be real precise on the joint locations because there's some wiggle room laterally like this. Cuts you a lot of slack. The biscuit joiner is set to cut a slot approximately in the center of my 3/4-inch material. The way that's gonna work is by allowing the fence of the biscuit joiner to rest on the top of the material. And then the weight of the biscuit joiner just suspends off of there, just like that. At this point, I'm about ready to cut my slot. I just wanna look here. Make sure that the center line on the biscuit joiner itself is aligned with the registration line that I put on my material. So once I've got my biscuit joiner draped on here and my center is good, then I'm ready to cut. Now, with a biscuit joiner in each slot, we can see how this came out. Perfect, now, like I said, there's a lot of, look at the lateral wiggle room that I have this way. So that's why your pencil lines don't have to be absolutely perfectly located. What this does, if you look here across the end, it provided perfect registration across these surfaces because the fence was resting on this one when I made that cut, then it was resting on this one when I made that cut. So the thing to keep in mind with this setup is that it's all about the distance from the top surface down to the biscuit slot. The next setup we do is gonna be a little bit different. The application here would be, let's say I wanna put a shelf right in the center of an upright like in a bookcase or somethin' like that. And I wanna put those together with biscuits. So I've got another butt joint. Biscuits are gonna do a great job of reinforcing it. But what I need is a way that I can get those biscuits cut, the biscuit slots cut into this piece and this piece so that my registration stays the same. Obviously, if I keep the fence on here, I'm gonna have a really hard time cuttin' slots into the face of this piece. So this whole approach is a little bit different. I've got registration marks on this piece that shows me the bottom of the shelf that I wanna put on. Onto those registration marks, I put a cleat spanning from mark to mark. And then I need to clamp that down. Then I'm gonna give myself, on this one, it's quite narrow, I'm gonna just locate two biscuit slots on here. Now, in this case, I don't wanna use the fence at all. So I'm gonna pop this component off, and fold the fence up so it's out of the way altogether. On most biscuit joiners including this one, the distance from the bottom of the machine to the center of the slide is 3/8 of an inch 'cause the manufacturers have a pretty good idea that you're gonna use it in the way we're about to here. So what I do is rest the biscuit joiner now vertically on my piece. What I've got here is a registration slot, once again, showin' me the center of where the biscuit slot is gonna be cut. I put that onto my pencil mark. Bottom of the biscuit joiner against my cleat, ready to make a cut. Now what I wanna do is remove this. And I'm simply gonna transfer these layout lines to my shelf piece. Now, the thing to keep in mind here to be really accurate with this is to remember that in this application, I registered from the bottom up. So in this application, I also need to register from the bottom up. Very easy to do. All I have to do is lay my shelf on a nice flat surface with its bottom face down, bring my biscuit joiner over, align the registration point here with my pencil line. What we've done here is we've created an equidistant spacing, bottom up to slot, bottom up to slot, in both sets of slots here, so that I can perfectly locate my shelf right on those registration points I started with. So two different ways to use the biscuit joiner, just depending on the job that you're doin'. But just remember to think of it as registration from the top surface down or from the bottom surface up. Make sure you do it the same way on all the pieces in the project so your alignment comes out well.
What is the preferred biscuit size for 3/4" stock?
Confused . . . George marked the top of the shelf with left and right locations for the slots previously cut in the side and cut the shelf slots with the bottom of the shelf down. This keeps the registration distance correct, however the left and right slots only fit when the top of the shelf is installed down. (The shelf was flipped over at 7:36 and the slots were close enough to being equidistant to fit.) The shelf in the video must be installed bottom-up to precisely match the locations of the slots. IF the slots are equi-distant from the center, AND the shelf is 3/4" thick George's method will work. Recommend to mark the shelf for the slots with the bottom facing up, then transfer them to the top, and the shelf cuts made with the bottom down for the slots to locate AND register correctly. Cut a sample shelf using the demonstrated method with the Left side marked inward 3" from the edge and the Right side marked inward 2" from the edge to see the result if these words are confusing. Otherwise, a great video, George. this is an easy-to-miss step, especially under the pressure of performing for the camera.
You made registration marks on the shelf. But when you put the 2 pcs. together and flipped it over, now those marks were on the opposite sides of the way you marked them. Am I missing something?
I own the DeWalt biscuit jointer (BC). In order to make accurate cuts, the BC needs to be flat on the workbench, at least 4-5 inches from the edge and is best stabilized with 2 hands. The piece being cut needs to be clamped to the workbench within reach of the BC. Otherwise, the blade will tend to shove the workpiece away and laterally. Most clamps will not have the reach to accomplish this. You would need one of those deep throat clamps. Even so, the clamps tend to get in the way of the BC. When everything seems perfect, good alignment of the final joint is still difficult. Independent reviewers demonstrated that the biscuit-type joint was the weakest with the tongue-and-groove joint, my personal preference, being the strongest.
is the depth of cut always the same , if so how deep is the slot?
So, I get it that the tool places the blade 3/8" upward from plate edge which places the biscuit in the center of 3/4" plywood, but what if the shelf material was 1" or 1/2" plywood? How would you get buiscuit in the center of the shelf piece? I also have a similar looking Porter Cable joiner. Thanks!
I really enjoy all this info. I took up carpentry when I retired and sure can use this expert advise thanks