Thread: Help an idiot fix an 'upside down' mitre joint

Bit hard to say without knowing more about what you are making. Is it a frame part or a carcase side? Can you reduce the overall size of the whatever it is and cut the opposite side down to suit?

I'm making a four sided rectangular box, with each of the four corners mitered. I can't change the side length to make it possible to just cut the correct angle into the board. It seems like my only option is to cut off the dodgey part and fix on a replacement, the right way around, but I'm not sure how the best way is to do this.

There are a few splice joints you could use. Is it possible to arrange it so that the dodgey part isn't seen? It will be hard to join to bits together end to end without it being obvious. A splice might be your best bet. Can you change the height?

You may be able to glue the offcut back on, but the only glue I would use for this is expoxy.

To clarify:



A is the birds eye view of the box, showing the miter joints that will join the sides.

B is what each side should look like.

C is what the side I cut wrong looks like.

D is my proposed solution; cut off the wrong part, glue on another one.

Originally Posted by silentC

There are a few splice joints you could use. Is it possible to arrange it so that the dodgey part isn't seen? It will be hard to join to bits together end to end without it being obvious. A splice might be your best bet. Can you change the height?

I'll arrange it so this joint is at the back of the box. Can anyone offer a second opinion on the epoxy suggestions by echidna?

Thanks for the help so far silentC and echidna.

If you were prepared to make the box shorter, there is a way of fixing it using a scarf joint that is more or less invisible if the grain is not highly figured. You could retain the length and depth but the height would be slightly less. Let me know if you want to know how.

If you don't want to change any of the box dimensions (and don't want to pay for any more wood), then you'll need to glue a new bit on. I would use some kind of scarf joint or a splice. I don't think butt joining is going to be very successful. It will stand out. To splice it, just cut an opposing 45 deg mitre on a scrap bit and glue it on, then cut your new mitre.

You could:

1)Make a feature of the corners with a vertical 'post' in different timber, and a 2mm detail line. Might look a bit fussy though.

2)Cut off the offending northern hemisphere mitre with the thinnest blade you have. BS? Drive over to Lignum's place, and have him domino the cut piece on again. He'd love it!

Commiserations my friend, we've all done it.

Serendipity, I love. This is what I mean (thanks John):

http://www.woodworkforums.ubeaut.com...ad.php?t=34145

To confirm, does this diagram illustrate the process of using a scarf joint to fix it without changing the box dimensions silentC? If so, would you be using epoxy as echidna suggested, or do you reckon wood PVA will hold up ok?

Thanks for the suggestions TassieKiwi I'm in a real hurry though because I've gotta finish this asap for a present, so it looks like the above method is pretty much all stations go.

A scarf joint should be a much shallower angle than 45 degrees, but since it's a box and therefore won't be under to much stress you could probably get away with that. Definitely use epoxy however.

Yes, although a scarf joint is normally much longer, usually something like 8 times the thickness of the material. There's not a lot of long grain gluing surface there. If you use a good strong epoxy as Bob suggests, it should be OK. It's only a box and not subject to a lot of stress. I don't think I would trust PVA.

Tassi got it. Although im a fair drive away, i would (if i was in this position) just but it and put four 5mm dominos and PVA then re miter. It would be super strong, and the slight end-end glue line will just go to the back where the hinge will be.

Would it be possible to add a feature eg different coloured wood in the centre if the offending piece? [It would basically turn each side you do this to into 3 pieces].
You would also have to add one to the parallel side or all sides if you choose. What I'm suggesting is either a rectangle/ diamond shape in the centre of the side[s] - this would be fiddly sure, but would move the ends out far enough to fix the problem.
Just a thought, hope you get it solved,
regards,
Bob