Wow! That title is a mouthful isn’t it? It occurred to me when I was making glue blocks for some of the deck beams that this is a perfect opportunity to talk about how the proper use of a few tools makes cutting and fitting bevels easier than it looks. I used to think that the way pros got such tight fitting joints (when they weren’t standard angles, like 90°) was by simple trial and error. While that method works, and you still need to employ it from time to time, a tool called a bevel gauge makes the process so much simpler.
The simplest use of a bevel gauge is for a simple angle–set it against the piece you want to fit to, and transfer it to your saw or stationary sander, and duplicate the angle.
But the deck beams in between the full frames don’t have a good place to attach to the hull at their beam ends. We need to make glue blocks for these joints–blocks that will add faying surface for the glue. Simply put, we need extra surface area that will allow epoxy to create a strong joint. These glue blocks require a compound bevel–a joint that combines two angles. It ain’t as hard as it sounds.
The trick is to measure what I call the SAW BED ANGLE and the SAW BLADE ANGLE separately. Then you set them up on your saw, and make the one cut you need. Start in the middle of the boat. The angles are less acute there, and are a little easier to measure with your bevel gauge. By the time you work your way forward to the bow, you’ll be a pro. Of course after saying that, I used the deck beam closest to the bow to illustrate my examples here.
First, measure the SAW BED ANGLE on the boat. This is the angle you’re going to set the saw bed to (the miter angle on your saw). It’s important to lay the bevel gauge along the edge of the clamp (the clamp is the term for the longitudinal piece of the boat frame that lies alongside the hull and the deck at the hull-deck joint) that you want your glue block parallel with, and measure the angle at which the deck beam intersects.
Now carry your bevel gauge to the saw and set that angle on the saw. Be sure to hold the bevel gauge so that it lies flat against the fence of the saw. Don’t just lay it up there, or you’ll get some distortion of your angle.
Next, measure the SAW BLADE ANGLE by placing the blade of bevel gauge square to the face of the deck beam (not parallel to the clamp as in the previous step). Click on the picture and zoom in to see how the bevel gauge is oriented here.
Then carry your bevel gauge to the saw, set it square to the blade and set the blade angle of the saw. Close readers will observe a theme here. You have to make sure the bevel gauge is oriented the same way when you measure the angle and when you set the saw.
Now you have your compound bevel set up. Make the cut and check it against the boat. Chances are you’ll need to tinker with one or both of the angles a little. I sometimes have to take a little more off the heal or the toe of the piece to get a better fit. But the more you practice, the better you get. The nice thing is, once you get it dialed in, the complimentary angle works for the back side of the same joint. And since a boat is symmetrical, the same angle should work for the other side of the boat. Pretty soon, you’ll be whacking those glue blocks out in short order. Just about the time you get really good at it, you’ll be done. Isn’t that the way it always goes?