trunk body not square..possible to fix?

[Dave Tesch]

i put together a small trunk on wednesday (approx 22.5" x 19" x 17.5") out of 18mm birch. went together easily until the top piece which had a bow to it on one corner. normal hand pressure was enough to flatten it out. trunk assembled with 2" brads and glue, all butt joints.

i cut the top off (3") the next day and it no longer fits on the box properly. it is off by about 3/16", and if i line it up on the part it is off, it becomes off at the opposite corner.

t-square says the box is now a parallelogram and the lid is square. the box was square before i cut the top off, cutting it must have released some tension and skewed the box?

so far i cant think of any fix that doesn't lose real estate in the trunk opening (adding a brace of some sort).

what are some fixes i should look into?

[Chris Tsutsui]

This has happened to me before.

I would first make this simple clamp jig out of scrap stock, i made these on my miter saw. This allows you to put a clamp across the furthest apart corners of your parallelogram.

Then clamp to pull them together, and hold it there.

If you're lucky, you won't need to add a brace in there.

[Dave Tesch]

i can certainly give that a try!

[Dave Tesch]

i did try that and unfortunately when i took the clamp off the box went right back to where it started. i had clamped the box to opposite the amount of tweak - i hope that makes sense.

here is the box, you can see the lid does not fit correctly eve thought the lid came frome the box.



i have had a talk with someone who designs boxes using metal extrusions with tongue and groove and he suggested some sort of locating dogs to keep the lid true, but i dont have many ideas. it may just stay crooked.

[David DeCristoforo]

"... top piece...had a bow to it on one corner. normal hand pressure was enough to flatten it out...."

This would have probably been fine had you not needed to cut the top off. With the top attached to the deep sides, there was enough rigidity to hold everything in place. But you essentially built stress into the box which had to go somewhere. "Next time", reject the warped piece of material. For this box, you might be able to create a lip on the lower section by attaching some thin pieces of hardwood around the inside of the box so that they project a half inch or so into the lid. If you chamfer the top quarter inch or so of this "lip", it should serve as a "guide" to bring everything into alignment as the lid closes.

[Dave Tesch]

thanks for the advice. i heavily debated tossing the entire sheet after cutting into it as it was indeed a mess in there.

i think the hardwood around the inside idea may work well, there is plenty of room around the inside edge. maybe even enough for some triangles on the corners?

[David DeCristoforo]

If you could add some glue blocks in the corners you might be able to square up the box. Just clamp them in at first and see if they will do what you hope they will do. If they do, glue em in...

[johnny means]

Would it be possible to remove the bottom? If so, you could rack the base until the top of the case was square then reinstall a bottom that would hold the rack.