Techniques for using the right clamping pressure when woodworking.Wednesday, July 31, 2019, by Gregg Malanga
A big part of a woodworking clamp’s job is the ability to reliably apply pressure. Pony Jorgensen clamps do exactly that. Our bar clamps, C-clamps, and pipe clamp fixtures have been pressure tested to determine their maximum clamping force. And some of our heaviest-duty clamps for gluing wood are capable of applying nearly 10,000 pounds of it. But just because your car’s speedometer goes well past 100 miles per hour doesn’t mean you should drive that fast. (Please don’t.) Just because a clamp says it can provide thousands of pounds of clamping force doesn’t mean you should try to use Popeye-levels of strength when gluing up your next project.
The dangers of using too much clamping pressure.
If you use too much clamping pressure, a couple of bad things could happen. The first (and most obvious) is that you’ll squeeze too much glue out of your joints. Once what’s left of it dries, the bond won’t be as strong as it could have been. It’s true that clamping pressure can help compensate for any minor imperfections with your joint or gap, but you don’t want to overdo it. The second unfortunate result of using too much clamping pressure is the possibility of damaging your workpiece – especially if you’re working with softwood. Fortunately, many of our bar and pipe clamps come with pads to help protect your work no matter how much pressure you use.
Tips for applying the right amount of pressure.
Ultimately, the best way to learn is through practice. Over time, you will be able to easily identify how “snug” a clamp should be. But in the meantime, here are some pointers to keep in mind.
Don’t tighten softwood projects as much as hardwood projects. This one is pretty self-explanatory. Hardwoods can withstand more pressure than softwoods.
Tighten until you see the glue ooze a bit. Seeing glue ooze out of the joints is normal, and it’s a good visual indicator of when you’ve clamped hard enough. For easier cleanup after your glue-up, wipe away the excess glue once you’re satisfied with the clamping pressure.
Distribute clamping pressure evenly. They say you can never have too many clamps – and being able to evenly distribute clamping pressure is one reason why. The more clamps you can use to properly distribute the pressure applied to your project, the better. To ensure you’re doing this correctly, keep an eye on the glue oozing out of the wood joints. A consistent ooze across your project means the pressure is well distributed.
Why our clamps are stronger than you’ll ever need.
Pony Jorgensen clamps are intentionally over-engineered. We make sure they can withstand much higher pressures – without failing – than ordinary woodworking tasks require. Our reasoning is simple: if a clamp can apply 8,000 pounds of force, then using it to apply much less pressure will barely give the clamp a workout. It’s one of the reasons we’ve gained a reputation for high-quality, reliable woodworking clamps. View our entire product line and see for yourself. No pressure, though.