Undoing a Glue Joint

[Michael Moscicki]

I am in the process of making a unit of display shelves to hold various small items from trips and the like. I though I would be clever by gluing and clamping the top and bottom to the sides, separately from the middle shelves, in order to get it as close to square as my maple allowed me. Once dry, the top had a nice tight joint. The bottom, had a slight gap, but nothing I couldn't work around.

To give me a false sense of confidence, my four middle shelves were dry fitted with relative ease. Then came the glue up and things did not fit easily. I should have quit at the first sign of resistance, but I just kept pounding away at the shelf with a rubber mallet until it could be pounded no more. It did not reach the back by a considerable amount.

I tried a hair dryer for roughly 15 minutes per dado and mineral spirits. In the process I also managed to get a pry bar stuck in one of the dados. One side of the dado seems to have been loosened, but the side with the pry bar has no not.

Any tips on undoing a Titebond II glue joint? I've read vinegar could do the trick, haven't tried it yet as it was conveniently out of stock in the pantry.

At this point I'm leaning toward flush cutting the shelf out and redoing the dado, but wanted to ask the experts before I dig an even digger hole for myself. If I do that I would either do the same to the top and bottom or go buy more maple to cut a new shelf to the appropriate length.


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[Brian Henderson]

Titebond recommends a heat gun (hair dryer will not work) or acetone. Beating on it won't help, the glue joint is stronger than the wood and the wood will give long before the glue will.

For future reference, if you're going to do a partial glue up like that, make sure you have all of the shelves in place, without glue. That way, when you remove them, you can be sure they'll go back where they're supposed to.

Good luck.

[Gerry Grzadzinski]

I would have glues the top, bottom, and all shelves to ONE SIDE ONLY. Then, when dry, add the other side. Much easier.

[Lee Schierer]

Instead of the mallet, a couple of clamps would have pulled the shelf into position.

[Mike Henderson]

I would have glued the top, bottom, and all shelves to ONE SIDE ONLY. Then, when dry, add the other side. Much easier.

I would have done it this way, also. Trying to slide a shelf into a dado is tough. The glue has water in it and that causes the wood to swell - it can make a very tight joint.

Putting it it straight, as suggested by Gerry, is much easier. And using a couple of clamps to pull it tight into the dado, as Lee suggests, is also a good idea instead of hammering on it.

Mike

[Many people, if they have to slide a shelf in, will only put glue on the last inch or two of the shelf (not on the side), and only at the last minute, before the shelf is completely pushed into position. This assumes you were able to slide the shelf in okay during a dry fit-up.]

[Prashun Patel]

If clamps do not solve, flush and re-cut. But how will you recut? Do you have to cut the top and bottom off too?

Don't mallet too hard; you risk cracking your uprights. I'd rather waste a shelf than the uprights.