Clamping 90 degree right angle joints is a real pain. The pieces slip and move out of alignment and its a mad rush to get it all clamped up before the glue dries. This simple jig takes away all the hassle!
- 18mm Plywood
- Mitre Saw
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Step 1: Make Right Angles Triangles
First step to make the jigs is to square up one edge of the plywood. I used a piece of plywood that was 15cm wide but you can of course make them as big or small as you like. With the mitre saw set to 90 degrees cut a small piece off the edge. As a sanity check I like to double check with my carpenters square to make sure that it is in fact square.
Next, swing the mitre saw to the 45 degree mark. Make a cut to create a right angled triangle. The positioning isnt critical with this cut but I like to have the cut meet the corner so its an exact triangle.
To prevent the inside corner of the triangle interfering with the inside corner of what ever your clamping up its best to cut away the corner on the jig. I also cut away to outside corners to just take away the sharp points.
Step 2: Cut Spaces for Clamps
Now we need to cut space for the clamps to fit. Some people will drill large holes into the jig but I prefer to use the bandsaw to cut a couple of notches large enough to fit clamps in place.
This is the shape we end up with. This is the jig finished. Told you it was quick. Let's see how it works...
Step 3: How They Work
Usually when you need to glue up a right angle its a pain. The pieces move on you. You have to keep offering up the square to make sure its all still square in the corners. Its just a real nightmare to do. Especially when you're rushing with the glue setting up. That's where this jig comes into its own. It can be clamped in place to hold the pieces square while you either drive in screws/nails or get larger clamps in place.
I like to use spring clamps with the jig as they can be added with one hand. I add one clamp to the jig first. I can then offer up the other piece to jig and wiggle it all into place so that everything is touching and flush. The jig is square so with the pieces flush we know the joint is square. Another spring clamp added to the other side holds the pieces in place nice and square. Another sanity check shows that the corner is square and the pieces are held for me to add extra clamps or add screws/nails.
Step 4: Future Project Use
These right angle clamping jigs will be used in an upcoming project. I'm going to be bending plywood and need them to help me clamp the corners square. I really hope you make some for yourself!