How to fix an unsquare glued up box. Is it possible?

measure your corners, find the longer diagonal, put a clamp on it, tighten til square. It might stay, it might not, hard to say unfortunately.

-- The mark of a good carpenter is not how few mistakes he makes, but rather how well he fixes them.

Shaving an outside of 1/16” from a finished box is an ideal job for handplanes… Inside, obviously not so much… Got planes?

-- Don't anthropomorphize your handplanes. They hate it when you do that. -- OldTools Archive

I’ve made a lot of boxes, and have dealt with this problem more times than I’d like to admit. I have only found two possible courses of action:

1. Live with it.
2. Trash it.

-- Charlie M. "Woodworking - patience = firewood"

Gee Charlie, that seems fairly extreme, Black-n-White thinking.

Seems like he could cut it apart and make a slightly smaller box—if that were acceptable.
Cross-clamping is good before the glue cures up. It will fight you after the glue is set though.

-- "Hard work is not defined by the difficulty of the task as much as a person's desire to perform it.", DS251

This sounds extreme and I don’t even know if it’ll work but could you heat it up gently? Then maybe the joints would soften enough to re-clamp. It’s a small box so it should fit inside an oven. Say 150°F or so?

I still dream of making a box that’s 1/16” out of square!

-- "Do not speak – unless it improves on silence."

Thanks for all the suggestions. One thought I just had would be to use a combination of clamps and hot water to possibly loosen the joints. Thougths/comments are welcome.

Next time wait until the glue grabs, then take off the clamps and
check for square. Correct with a diagonal clamp if needed and let
the glue dry with the clamp in place.

Sadly, this time you are out of luck but you may be able to steam
the joints apart and reglue.

Cut the lid crooked to match? You won’t fix the box, unless you can live with a smaller box!

You might also check if it is flat- lay it on your table saw and look for wobble.

-- Dan V. in Indy

Depending upon the glue used the idea Jeff in Huntersville had has merit. I use a heat gun to loosen joint on chairs that need complete rebuilding.
MIKE

-- See pictures on Flickr - http://www.flickr.com/photos/44216106@N07/ And visit my Facebook page - facebook.com/MTEnterprises

I want to make sure I read this right.
You’re worried about one sixteenth out of square?

I once done an exercise.
Ok, it waas suggested to me as a challenge to myself.
Each day for a week (seven days), I tried my best to make a perfect box. We’re talking six sides (four side and a top and bottom actually). The trick was that it had to be perfect in every way. The measurements had to be EXACT.
Yes, these were supposed to be useable boxes with hinged lids. They were just square for the pupose of the exercise.

Seven days I tried. Seven days I failed.

Then the same friend told me to do a new exercise. Pick the worst out of the boxes and show it to as many people as I could find over the next seven days and see if they could tell if anything was wrong with it.

So I did. Guess how many people found the flaw in my 12×12x12 box that, only I and my friend knew, was about an eight of an inch out one way and about 3/16ths out of square the other?

None. Zero. Nada. NOBODY could, even with some going over it with a fine tooth comb trying to find what was wrong with it, could find a single thing wrong with them.
Well, actually, that’s not correct. Some people said things were wrong such as finish, hinge choice, and such. The point is that noone could tell it was out of square.

As my friend (a woodworker of over fifty years) told me later, the point of the two exercises was to prove the futility of trying to make a square box perfect in every way and just how much it really meant to the general public.

-- http://wddsrfinewoodworks.blogspot.com/

1/16 ? really? OK get a really big hammer….

-- If the old masters had power tools, they would have used them. So get off your damn High Horse.

First of all I would like to that everyone that provided a logical, sensible suggestion. I appreciate your help.

Regarding the other comments, they were useless and unhelpful. If you cannot say something helpful, do not bother with a reply.

Phil, get a sense of humor, man.

Do you consider William’s answer to be useless and unhelpful? He really spelled out in long form what I was trying to say in a very few words. And it’s good woodworking wisdom. We often find flaws in our own work that others will never see.

Reading over all the comments, I don’t see a thing in any of them that is mean-spirited or negative. People are just offering their points of view. Take what you like and leave the rest.

-- Charlie M. "Woodworking - patience = firewood"

Dealing with only a 1/16 out of square I would assume putting a square bottom in it would square it up?

-- W James Brokenbourgh Custom furniture maker http://artisticwoodstudio.com/