Anybody love their corner clamps? I need some.

January 12, 2022 1:09 AM

I have been enchanted with the apparent ease of corner clamps like these, but I suspect they really aren't that great to use. I want to clamp things from 1/4" up to 1.75" or even more, and these are too small anyway. Plus there are umpteen different versions. Can you point me to some convenient and not-too-expensive corner clamps? Of any type? I would like to be able to make boxes quickly.

I already have a strap clamp...somewhere. But I want something easier to use, and that I can use to clamp a single angle, a small item, or a T joint.
I also already have a right angle I can clamp things to. I'd like something, though, that has the clamping action built in, so I don't have to somehow grow a third hand to use it.

Finally, I'd love to be able to own several of these, so price does matter.

All the online review/best of lists I can find seem to be obvious click bait with zero reasoning involved, and the options when searching online are overwhelming.



My current plans are to make some larger items out of 1x4, 1x2, 2x4, and 2x3 lumber. Plus 1x12 boxes and some cabinet/case type stuff -- but it's OK if I need different clamps for this larger stuff. Just -- I've used the strap clamp, and it's a pain and it doesn't guarantee right angles.

The priority task for today would be clamping 1x12's together and 2x4's together.



What do you love? Thank you!

posted by amtho to Grab Bag (9 answers total)

The clamps with little springs are fine for things that only need to be held lightly. But there are times when your cuts are a fraction of a degree out, and you need a clamp that you can tighten by hand to close a tiny gap and get things perfectly straight. Or when the weight of the thing you're clamping just means you need more force.

There are a couple of types of clamp I use a lot. There's the larger, heaver type that have a single handle that goes in at the corner. Advantages: works with larger timber, tightens with one hand. Disadvantages: heavy, can be tricky to get into position, more expensive. And there's those smaller metal ones that tighten using two separate handles. Advantages: light, easy to adjust with clamping pressure applied independently to the two sides, cheap. Disadvantages: a little flimsy, small clamping area.

I find myself using the smaller clamps mostly, even for larger pieces. Often I'll double them up and use two clamps opposite each other on a single corner. I probably have 20 or 30 of those clamps, because they're pretty cheap.

I'm sure there are more expensive, more capable clamps out there. But those cheap, basic aluminium corner clamps have served me well, especially on projects with lots and lots of corner joints.
posted by pipeski at 3:25 AM on January 12, 2022 [1 favorite]

And get yourself a speed square, if you don't have one. They make checking right angles so much quicker.
posted by pipeski at 3:27 AM on January 12, 2022

Keep in mind that corner clamps are mostly useful as extra hands to hold things in approximate position while you drive fasteners or place *other* clamps to apply pressure to the joint(s). Corner clamps that both hold parts in position and push them tightly against each other aren't really a thing, except for the strap clamps you mentioned which are awkward to use and only work on mitered polygons. The demands of specific clamping situations, i.e. different thicknesses and lengths of wood, mitered vs. butted 90-degree edges, etc. are so varied that you'd need many very specialized clamps to do it well, and the collection would be too expensive to justify. Also, wood components are so often slightly warped or bowed that clamps which forcefully hold two pieces of wood at a "perfect" 90-degree angle aren't as useful as you might think, because 90 degrees measured in the first few inches on either side of a corner puts the far ends of the imperfect sticks/slabs in the wrong places. So, a handful of good-enough cheap clamps to help with positioning as pipeski suggests is about as much as you can hope for. The way to get larger rectangular assemblies squared up is to tweak the positions of ordinary bar clamps to make the lengths of the diagonals equal.
posted by jon1270 at 4:49 AM on January 12, 2022 [2 favorites]

Response by poster: pipeski, I have _two_ speed squares.

This is great information. I was looking at those DeWalt corner clamps previously, so you've reassured me -- they look like they might be metal, but the price makes me wonder about that.

jon1270, that information about how they're actually _used_ is super helpful. Thank you.
posted by amtho at 6:29 AM on January 12, 2022

amtho, I don't have the DeWalt ones, but every clamp of that type that I've seen has been alumin(i)um. Even the cheap ones I've bought at bargain stores.
posted by pipeski at 7:05 AM on January 12, 2022

I have used a light corner clamp, and it was less than satisfactory for my purposes. I think it was meant only for picture frames, and I was clamping 2x2 lumber. I wound up replacing it with this one, which worked better. One thing I discovered is that the clamp needs to be deep enough to apply pressure more or less to the centerline of the workpieces, or they won't line up right. It worked a lot better, but jon1270 is right.
posted by adamrice at 7:07 AM on January 12, 2022

Woodpeckers makes all sorts of fantastic clamps, squares, etc. Buy once, cry once.
posted by xedrik at 7:53 AM on January 12, 2022

I use corner clamps made from plywood. Cheap! (because the pieces are small enough that they'd otherwise go in the burn pile).
I use a design something like this, but modified to use some junk I already had in my pile of "possibly useful bits removed from stuff".
I painted mine with bright blue car paint so I can find them.

The woodpecker style ones are nicer. They (or an aliexpress copy of same) would be a nice luxury to have.

When actually getting things square is important to me, I just do a box/finger joint and then I have time to fiddle with adjustments (or jamming in a square to clamp to) without needing that third hand.
posted by Acari at 9:28 AM on January 12, 2022

If you've got the budget maybe Rockler's cabinet maker set.

People also use tie down straps for box/carcass assembly instead of proper strap clamps, sometimes with a pin nailer to hold the joints while the glue initially sets up.
posted by snuffleupagus at 7:16 PM on January 12, 2022