how to unglue something

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After realizing I had cut the top of my paperback organizer too short by neglecting to add width for the rabbet it was going to sit in I cut a new top from some free pine ply offcuts, figuring that very few people will see the top. I was also kind of irritated at myself and did not want / could afford to buy another sheet of birch plywood to correct my error. The free wood has a little bow to it that I was not able to put enough force on to unbow it during assembly.

I would now like to remove this and do things right - maybe I'll use up the rest of the Lowes gift card I received for winter holidays on the birch ply. Maybe I'll mill some solid maple I have in back. Maybe I'll do something else, but I don't like the bowed plywood - it is interfering with my thoughts to go forward with this project.

The plywood in question is screwed and glued in place. I think I used Titebond 1. After double checking that I have, in fact, removed all of the screws what is the best way to make the glue fail so I can remove this plywood piece and start over?

Thanks!
 
Mark,
A heat gun will soften the glue, but you've gotta be very careful not to burn the wood in the process. The heat will also burn any finish that's on it.

Try using full strength white vinegar. Warm it a bit, and drizzle it into the joint, a little bit at a time. It'll soften the glue, and allow disassembly, but will leave a gummy glue residut that you'll have to scrape off. Then, you'll need to neutralize the vinegar with a little baking soda dissolved in water so that you can re-glue the joint.

Messy, and time consuming, but it works.

Woodcraft used to sell (maybe still does) a product with a name something like "D-Glu-It" that was (is) basically a gelled vinegar. I used it several years ago, but actually found the straight vinegar to work better. YMMV.
 
Heat and if possible, a little steam for PVA. Harbor Freight heat gun - $10. Steam Iron with a "burst-o-steam" button(?). Take your time and if you pry, try to use something that has a nice wide face. A screwdriver will most likely damage the keeper piece you are levering against. Something like these (doesn't have to be these) would work. Any friends do body work? They have plastic wedges and pry-goodies.
 
One possibility is the cut the bowed plywood and then re-cut the rabbet.

It might be an excuse to buy one of the lower cost oscillating tools. I'm in the process of buying a Rockwell Sonicrafter myself.
 
i had run into a similar problem myself a while ago. somehow, my mortising machine cut my needed mortises off by just a tad on some frames i was making. i had a brilliant idea about how to fix, but not how to seperate the parts that were glued together. just for the fun of it, i started tapping one of the bases with the persuader (a large mallet turned from a 4x4 of hard maple), and after a few light taps, everything came apart. titebond will hold good on normal stresses, but i think will give way on shear loads. either way, i solved the problem, remortised, and obscured the error with round felt pads.

dan
 
Back in my classroom days I would dribble Titebond glue on my pants and shirts much to the displeasure of SWMBO when I got home, She would often rescue me (If I fessed up and told her) by soaking the damaged goods in White Vinegar. As was previously stated by someone who had also been there and done that :eek:

I would use some Vinegar and some heat but not too much of the steam as plywood has a tendency to delaminate under steam treatment.

Soften with the Vinegar and do the wiggle and see if it won't let go.

Please report back with the results.
 
Thanks for the replies so far. Especially the warnings to not be too aggressive with respect to plywood delamination since my keeper assembly is itself 3/4" birch plywood. I had thought of trying to recut the rabbet to clean things up when done, but the rabbet is now 6' high and it would be more trouble than worth to move the assembly to lower the rabbet. I'm building the thing in the basement where it will ultimately live, but the basement ceiling is not tall enough to permit rotation of the assembled carcass. I'm designing the piece to be able to be moved out of the basement if/when we move, but basement entry is through the attached garage (the shop) and there is not space to move the thing with my tools all set up.

Will heat / vinegar also loosen plywood glue?

Also, I'm wondering if maybe I should just accept the loss of 3/4" interior shelf height capacity and put the birch ply that was supposed to be the top just underneath the free wood that is the top now. If I'm careful to not attach the birch ply to the bowed parts the birch ply should be free of bow.

I could rout grooves in the birch ply before installation for use as shelf guides.

Starting to think that this is the best lemonade option. That and remembering to always triple check measurements when dealing with dadoes and rabbets in the future. :doh: :doh:

Read my own post - if I did decide to remove and reinstall a correct piece, would the handplane police come arrest me if I used my rabbet plane to cleanup the leftover wood and glue bits? I'd need to sharpen the blade again before using it for something else, but this seems safer than spinning a router bit at 20,000 rpm above my head.
 
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