Thread: Serious warping/bending from CA glue

I have read a bit about CA glue as a finish but haven't come across this. I'm using some spalted hackberry which is pretty soft and porous for some scales. I used some of the thin (red bottle) hot stuff glue on both of the scales on the inside wall. After it dried, the scales were bent pretty harshly. I'm guessing this is from the glue setting and pulling. Can anyone offer some advice on how to fix this (presuming it can be fixed) and a possible better solution for this problem?




Cheers,
Jonah

Putting CA on the other sides would seem a logical thing to try.
Many applications where glue is used need something to balance the stresses.

Both sides is a good start. My experience has been not so good if they warp like that. Once they fully cure/dry, you might try to press them flat for a few days, but even that didn't work for me...I had to start over. Hope you can save them.

You could sand it back to bear wood, clamp the scales between two pieces of flat board or tile (I prefer the later), bring some water to boil, and pass the contraption back and forth over the steam heating the wood and letting it cool a bit. You could do this for a few minutes a day for a couple of days to see if it will help flatten them out. Then I would sand the backside w/ 50grit and attach a liner to help offset some of the stress. Those really soft porous woods when sanded thin for scales will warp from the heat of curing glue and epoxy sometimes.

As already said, be sure you treat both sides of your wood in exactly the same way. In bookbinding, you have to glue both sides of any paper or board, because it'll swell a little from the glue's moisture, then shrink as the glue dries and tightens. It's critical to make sure that all this happens equally on both sides of whatever, or your flat surface will warp in one or two or three dimensions and you'll end up with a really wanky looking book.

Thanks for the responses. I was pretty surprised when it started looking more like a pair of boomerangs instead of a set of scales. I'll try some of the suggestions and see how far I get.

Originally Posted by roughkype

As already said, be sure you treat both sides of your wood in exactly the same way. In bookbinding, you have to glue both sides of any paper or board, because it'll swell a little from the glue's moisture, then shrink as the glue dries and tightens. It's critical to make sure that all this happens equally on both sides of whatever, or your flat surface will warp in one or two or three dimensions and you'll end up with a really wanky looking book.

Cool, are you a bookbinder?
My mother is a master book binder specialized in restoring antiques.
It's from her that I know this. If she binds a book in leather cover, she also has to glue the insides of the cover, or the glue will pull so hard that the cover will warp like a bowl.

I gave the scales a few steam baths and had them pressed overnight with a 15 pound anvil. I'm quite surprised how much the scales flattened out. They aren't perfectly flat, but they are pretty close to it. I'm debating now if I should CA glue the other side of the scales or just soak them in polyurethane and call it a day. I don't know that the scales will be salvageable if they bend again.

Even if slightly curved,Perhaps doing a 3 pin configuration may be in order,just a thought.

Originally Posted by pixelfixed

Even if slightly curved,Perhaps doing a 3 pin configuration may be in order,just a thought.

A three pin set up is actually part of the original design. I'm going to do some more passes of steam/pressing the scales and see if I can get them any flatter. I'll post another picture once my phone is charged up.