Making Strong Mitered Corners
George VondriskaDescription
If you’ve used mitered corners on any of your woodworking projects, like a picture frame, you may have been concerned about getting enough glue strength in the joint. Here’s a dirt simple trick for making sure you get all the strength you need in your miter joints.
What’s the problem?
The problem with mitered corners is the end grain. End grain in wood looks like a bunch of soda straws, and those “straws” quickly wick up glue, which affects the strength of the joint. The trick to avoiding this problem is pre-treating the end grain. No special products needed for this. Pre-treating is done with something you’ve already got in your shop.
Cutting miters
Plenty of woodworkers struggle with creating miters. It can be tricky. You’ve got to make sure your tools are set up just right, or the miters won’t come out right. The cumulative error adds up quickly, making all of your mitered corners look bad. If you’re making your miters on a miter saw, double check your miter saw setup before cutting your first miter.
Gluing and clamping
Assembling woodworking projects can be tricky. There are lots of great tricks and tips you can use, and WoodWorkers Guild of America has you covered with great info on how to glue and clamp wood together. Be sure and check out our videos and articles.
More info
For more information on Titebond Original Wood Glue visit www.titebond.com or call (800) 877-4583
The thing that everybody complains about, any time end grain is involved in a glue up, is the fact that end grain does not have a lot of inherent strength, and the deal with it is that end grain looks like a bunch of soda straws. When we put glue on here, it tends to absorb so much, we don't have a lot of glue left behind, to give the joint it's strength. We're going to take care of that, with a pretty simple process here. It's called sizing your end grain. The sizing mix is very easy to get, or make. What I've done, is taken my standard yellow glue, and in this cup, I've got a 50/50 mix of water and glue. Using that, step one in the process is, brush that on. I'm going to get that on every one of my miters, let it dry just a little bit. I'm going to let that dry for about two minutes of so, and then we'll come back and do the assembly. It's really important when you're doing this, that you remember to dilute the glue. If we just let that build up there, in it's standard viscosity, the glue itself is going to be way too thick, and it's going to be really impossible to get the joint to go together. So, I'm going to keep giving my miters the brush off here, then we'll come back and we'll do an assembly. Checking on my sizing, it's dry to the touch. Now that tells me, I'm ready for the next step. Not bone dry, I can still feel just a little bit of moisture there, that's where we want to be, and it's interesting, you can tell that it's diluted, because there isn't a big film of glue on there, that's want we want. Now, we go back to a conventional gluing technique, I'm using the glue full strength. We'll get glue on our miters, and be ready to put our frame together. I really like band clamps for frames, because they put uniform pressure on all four sides, and I don't have to chase the pieces around, because they're all confined inside the clamp. A little bit of pressure from our band clamp, and that's going to take care of this. We'll let the glue dry. Sizing end grain, is a great way to make sure, that your glue is effective, because we're not simply allowing it to all soap up, into the end grain. So, next time you've got an end grain glue up, like a mitered frame like this one, try that sizing technique, and it's going to really bring a lot of strength to your joints.
Can you let the sizing mixture dry completely? I was thinking I would like to treat all of my miters ahead of time, and then glue them up at another time. Thanks.