Edge gluing boards to make a wide panel can be a nightmare if the boards aren’t all perfectly flat, and they rarely are. The typical solution is lots of fussy manipulation with clamping pressure and muscling things with a mallet to get everything as flat as possible, then planning or sanding afterward. Another faster alternative is Larry’s Clamp.
Originally invented by Larry Devers (hence the name), the clamp is now marketed by Charles G.G. Schmidt & Co., Inc. It is one of those why-didn’t-somebody-think-of-this-sooner kind of devices. Using a pneumatic piston to press a crowned metal clamping bar against a beefy steel anvil bar, the clamp uses air power to muscle recalcitrant boards into flat submission for clamping.
How it works
To operate Larry’s Clamp, you first hook it up to a compressed air source that will deliver a minimum of 90 psi and a maximum of 150 psi. Obviously, with the amount of force applied by the pressure bar against the anvil, there is a major pinch hazard to consider, so the device is designed to require two-handed operation. One hand holds the clamp and operates the safety trigger while the other hand operates the slide valve on top of the unit that sends air to deploy the pneumatic cylinder and close the clamp.
You set up your boards for gluing just as you would normally, applying glue to the edges and laying them across your bar clamps. Then you activate Larry’s Clamp over the boards to flatten them before tightening a bar clamp about 2 inches from the device. Next you move Larry’s Clamp 12 inches or so to the next clamping position and continue until all clamps are applied.
Flat and fast
Compared to pounding away with mallets and such, using Larry’s Clamp to flatten the glue-up is a breeze. You can adjust the speed of the pressure bar to help bring especially bad boards home, but it would take some pretty nasty wood to be able to stand up to the 500 pounds of pressure of Larry’s Clamp. The original size of 18 inches can handle panels of 20 inches or more depending on the width of the boards (the clamp just has to span all the glue joints). There are also 22 and 36-inch units available. Prices start at $459 for the smallest unit, which could be a real time saver if you glue lots of panels. For more information, visit www.cggschmidt.com.
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