Wise Buys: Right-angle Assembly Squares
Machining stock precisely is only half the battle in creating projects with square corners. You also have to assemble and clamp the corners squarely. To do that you need assembly aids that hold those right angles until the glue dries or you can secure those corners with screws or nails. We recommend the models below. You also can save money by making your own braces using the free plan at woodmagazine.com/brace.
Rockler Clamp-it squares
4" brace (#27767); 8" brace (#29190); 4" clamp (#20201): 5" clamp (#61003); Deluxe kit (2 braces and 4 clamps in each size)(#69970)
Iniitially, I was skeptical that plastic squares would be durable and accurate. Not any more. These lightweight clamping aids proved tough, precise, and helpful as I put them to use in several projects. The squares have three features that make clamping easier. First, the beveled outside corner doesn't get into glue squeeze-out. Second, notches in the arms receive the proprietary clamps to hold them in place. And third, the 8" models have predrilled holes in the body, and I used them to screw the squares to a plywood base, creating a 90° fixed clamping station.
I'm not as crazy about the provided clamps, though. They're miniature bar clamps, but different in that the tailstock slides along the bar while the headstock remains fixed. These take some getting used to, and they definitely require two hands to clamp a brace to an assembly. (Rockler promotes this as a one-handed application.) I'd prefer F-style clamps with sliding headstocks. I also found that on the notches nearest the corner, the clamp bars hit each other.
—Tested by Marlen Kemmet, Managing Editor
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Jevons 3-D Clamping Squares
Set of 4, clamps not included
Shop-made right-angle braces help get my projects square and are easy to make, but too often they get banged around to the point of becoming unreliable. So I like the durability of the Jevons 3-D squares, with rigid 3⁄16 "-thick aluminum angle that holds up to abuse from clamps and mallets. But their best feature proves to be accuracy: The 6"-long arms are perfectly flat and exactly 90° to each other.
Lately I've been building a lot of cabinets and while assembling the carcases, face frames, and drawer boxes, I found them valuable for holding mating parts true while getting the clamps in place. The result: flawless 90° corners. I also like the predrilled holes in each brace. With these you can screw them right to a project (if the holes won't show), or you can make jigs by screwing them onto plywood or MDF. I was able to use any style of clamp with them, so you don't have to buy special ones just to use these squares. They're versatile, lightweight, accurate, and affordable. Who doesn't need that?
—Tested by Kevin Boyle, Senior Design Editor
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Pinnacle Clamping Squares
23⁄4 " brace (#147850); 6" brace (#147530); clamps not included
In the past I struggled with trying to get drawers square—even half-blind and through dovetails and box joints--while measuring the diagonals and adjusting the clamps before the glue could set. Pinnacle's squares eliminate that worry. All I have to do is lightly secure two squares in opposing corners (I use small F-style or one-handed bar clamps) to hold them square, and then add longer clamps to pull the joints together tightly.
These machined aluminum squares proved accurate to within 0.001" of 90° over their 6" length. I like the rounded corners that allow clamping inside or outside the box without getting into glue squeeze-out. To help assemble a bunch of picture frames, I screwed three squares to an MDF jig, guaranteeing three square corners. Then I glued the pieces, placed them in the jig, and clamped the fourth square against the open corner for perfect frames time after time. The small models also worked great for squaring the bracket feet on a bookcase.
—Tested by Bob Hunter, Tools & Techniques Editor
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