I had to try it for myself

[Cliff Polubinsky]

I've seen people clamp a mitered box with painters tape. And I've read that if you're using plywood you can glue miters with no additional reinforcement. I've been slightly sceptical about both claims. So yesterday I tried it.

It works. Put the box in clamps this morning and couldn't pull it apart. This is going to open up some nice possibilities. One of the things I do is make urns for people that need them for a loved one or a pet. They're provided at no charge. Up until now I've been building them out of solid wood. But recently I picked up a vacuum veneering system and this is opening up a lot of nice things I can do with veneer. And being able to build the box like this simplifies things a lot.

Is there anything I'm missing that could cause issues a few years down the road?


Cliff

[Mark e Kessler]

I have done hundreds if not more in for all sorts of things in my cabinetmaking days with no issues, Blue painters tape works but clear packing tape can do a better job you just have to be careful removing it so it doesn't tear the wood fibers, the additional benefit of the clear is you can see the joint. also one other trick to cleaning up the corners after sanding flat is to take a round shaft and run it over the corners to kind of burnish and fill any small gaps then lightly sand, I use a screw driver, sometimes it helps sometimes not

would be easy to add kerf cuts to the corners and add a contrasting wood, would add to the look and add a little more strength.

[Jim Becker]

I often use painter's tape for "clamping" things in my work. For your application, it's great. You might consider creating a little jig to help square things as you glue and wrap the mitered boxes...I use that for photo panels I make for a local photographer in a custom size. (although I do use pin nails for those because of it being a production type assembly operation)

[John Gornall]

I've been using stretch tape with success - no adhesive, sticks to itself - rolls 4 inches wide.

[Charles Lent]

What ever will hold the joints in alignment and together, until the glue sets up will work fine. I build a lot of boxes, mostly from Baltic Birch, and mostly with box jointed corners. I use Bessey clamps to pull the joints together and keep them square, but remove the clamps when the glue sets up and way before the glue is dry, usually within 2 hours of gluing them up. It's been a very long time since I've had a joint go out of alignment or fail. To make certain that the box is, and remains square, I check the diagonal dimensions several times before and after the glue is setting up. If I see any movement toward out of square, I'll add a clamp or tow to correct it. The glue, in it's "setting up" state is flexible enough to allow this adjustment, and the box dries perfectly square. Clamps work best for pulling box joints together, but mitered joints that fit together well are better clamped for gluing using most any tape or banding method that will keep the joints from moving, until the glue is partially set up. Then these can be carefully removed much the same is the clamps in my box jointed boxes. For mitered corners, I usually insert biscuits or cross grain splines which keep the joints from slipping while the glue is setting up. I also found that cutting the mitered joints at 44.5 degrees rather than 45 makes the outer corner more likely to be tight, and if there is any joint gap it will be toward the inside of the joint. Of course, if you can always cut an exact 45, this isn't necessary.

I get to use the clamps to assemble many more boxes this way, and removing the clamps that were used to pull the joints together after the glue is partially set up allows the box sides that may have bowed slightly from this higher clamping pressure to straighten to normal before the glue hardens.

Charley

[Lee Schierer]

Remember when you are making mitered joints you are essentially gluing end grain. It is best if you coat both halves of the joint with glue to prevent glue starvation due to it soaking completely into the sand grain.

[Mike Henderson]

I used to do mitered joints like that. Then one day, I dropped a box and two of the corners came apart. I now put an ff biscuits in each miter joint. I haven't had any failures since then.

Mike

[John TenEyck]

Remember when you are making mitered joints you are essentially gluing end grain. It is best if you coat both halves of the joint with glue to prevent glue starvation due to it soaking completely into the sand grain.

Not the case with plywood like the OP is using. Half the plies will be long grain.

John

[Lee Schierer]

Not the case with plywood like the OP is using. Half the plies will be long grain.

John

Ah, yes that is correct but the other half are still end grain and those areas will suck the glue right out of the joint. If you don't believe me make miter joints from plywood and assemble one with only one side of the joint coated with glue and another with both sides coated. You'll be able to see the difference yourself.

[Cliff Polubinsky]

If you don't believe me make miter joints from plywood and assemble one with only one side of the joint coated with glue and another with both sides coated. You'll be able to see the difference yourself.

Lee, in the test I did I put glue on both sides of the miter and after curing I couldn't pull it apart by hand nor break it apart with clamps.

Cliff

[Bill Dufour]

I think the self adhesive stretchy athletic tape might be good. It is reusable. No idea if leaves a residue behind. Better not be silicone.
Bill D

[Jim Becker]

I think the self adhesive stretchy athletic tape might be good. It is reusable. No idea if leaves a residue behind. Better not be silicone.
Bill D

"Vet wrap" (similar also used in athletics) is indeed useful (and I believe every shop should have some at least for their first aid kit, too) and could be used to bind things together, but since it doesn't stick to the material...only itself...it may require something else to hold the workpieces in place while you do the wrap. I do have several rolls in my shop actually...don't have the horses anymore so the shop seems like the best place to keep it for future use.

[Mark e Kessler]

you can fix that by sizing the joint first

Ah, yes that is correct but the other half are still end grain and those areas will suck the glue right out of the joint. If you don't believe me make miter joints from plywood and assemble one with only one side of the joint coated with glue and another with both sides coated. You'll be able to see the difference yourself.

[Lee Schierer]

you can fix that by sizing the joint first

I've done that as well and it works, its just more work to prep the sizing, apply it let it set up and then glue the joint.