Taking apart glued joints (PVA)
#20
I take it you did not do a dry fit?

Dry fit ups catches most joint problems.
Steve

Missouri






 
The Revos apparently are designed to clamp railroad ties and pull together horrifically prepared joints
WaterlooMark 02/9/2020








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#21
(06-18-2018, 10:11 PM)Stwood_ Wrote: I take it you did not do a dry fit?

Dry fit ups catches most joint problems.

I sorta did a dry fit. The joints were so close when I did that so I figured they'd pull together perfectly when I applied clamping pressure. Boy was I wrong.

As far as the vinegar and heat thing, I've heard of that, but I don't have a heat gun. I also am afraid to melt the glue joints that have some supporting rails on the inside of the case. I used Gorilla glue for those since they were being glued to a surface with finish on it. Is that more heat resistant than Titebond 1? Are there ways to heat up the joint in a more targeted way? Could you drill a hole in a spot you won't see and then inject a small amount of boiling water through it and let the steam soften the glue?

I think if I do end up going the route of heating the glue to soften it and re-doing my glue up, I should use some kind of slow-setting glue, especially since it's summer time and the Titebond 1 starts to set up quicker in the heat.
Near future projects:

-Curly Maple display case
-Jatoba and Quilted Maple dresser
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#22
You may be spending hours (or days) trying to get it all apart. I'd cut those frames out....if you want to save them, trim them square on the TS, then glue replacement pieces onto the edges. Clean up the dados, put the frames back in.
I started with absolutely nothing. Now, thanks to years of hard work, careful planning, and perseverance, I find I still have most of it left.
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#23
(06-18-2018, 11:02 PM)KingwoodFan1989 Wrote: I sorta did a dry fit. The joints were so close when I did that so I figured they'd pull together perfectly when I applied clamping pressure. Boy was I wrong.

As far as the vinegar and heat thing, I've heard of that, but I don't have a heat gun. I also am afraid to melt the glue joints that have some supporting rails on the inside of the case. I used Gorilla glue for those since they were being glued to a surface with finish on it. Is that more heat resistant than Titebond 1? Are there ways to heat up the joint in a more targeted way? Could you drill a hole in a spot you won't see and then inject a small amount of boiling water through it and let the steam soften the glue?

I think if I do end up going the route of heating the glue to soften it and re-doing my glue up, I should use some kind of slow-setting glue, especially since it's summer time and the Titebond 1 starts to set up quicker in the heat.
Heat gun is quite targeted. Damp rag to make it moist heat is very targeted. It will work. If by Gorilla Glue you mean their polyurethane glue, the incidental contact with the heat and/or moisture won't make it suddenly fail.

GG makes a wide range of products.
Don't sweat the petty things and don't pet the sweaty things. -- G. Carlin
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#24
(06-18-2018, 09:11 PM)KingwoodFan1989 Wrote: All but one of the gaps are already filled with solid wood, though, and it's glued in place. How would I get that out? Most of what concerns me is that white residue. If I could get rid of that, I might be able to make it work without having to potentially heat up the joints and take them apart and re-glue. It would still be ideal to get the joints perfectly tight without any patches or fillers, though.

Also, I'm using Jatoba, not Mahogany, lol. It's one of my favorite woods, but all of my projects I've made out of it up until this point have had significant flaws. I know, Lord willing, I still have the rest of my life to do many more projects out of Jatoba, but I feel it's about time I do justice to it and make this project have as tight of joints as possible, whether that be through separating and re-gluing the joints or just making seamless repairs. 
Yes
I don't see it being any trouble to eliminate the white residue if you try the sawdust/glue mix on it. Surely that would sand back with the mix to bare wood and filler where the gaps were. And yes I knew it wasn't mahogany, but the grain is very similar, was what I meant. I built a fair amount of bathroom builtins out of spanish cedar which is softer but looks similar also. Never had any issues with repairing small defects with that method.
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#25
(06-18-2018, 06:55 PM)KingwoodFan1989 Wrote:  I pre-finished all the parts...

At this point anything you do to try and get the glued joints apart is going to leave you with a huge mess. My personal feeling is that you either have to scrap it or live with it, the time and effort that you will spend chasing the mess around is going to be longer and more frustrating than a do-over.
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#26
Have you tried applying finish to the joint? Maybe from machining after finishing that is what is causing the white appearance. If the white is no longer there you may not be drawn to the joint.
Fill your heart with compassion, seek the jewel in every soul, share a word of kindness, and remember; the people's what it's about.
Capt. Tony Tarracino


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#27
(06-19-2018, 04:59 PM)paarker Wrote: Have you tried applying finish to the joint? Maybe from machining after finishing that is what is causing the white appearance. If the white is no longer there you may not be drawn to the joint.

I did, and it didn't totally help. I've decided this: A couple or more here have suggested I don't unglue it and rather just scrap the parts and redo it that way...I think that's what I'll do. I can just use my jig saw and a flush trim saw to cut out the frames and make sure there are no protrusions from the dadoes. Poplar (the material most of the frame is made of) is borderline dirt cheap, so I'll pick up some at Home Depot later. Also, I have some extra Jatoba pieces that I can use to at least glue a thick piece of that species onto the front edge of a piece of Poplar (the side you see from the front of the case). I'll have to redo the dadoes in two passes again since they're filled, but this time what I'll do is clamp several guide fences (one for each dado) onto the sides of the case and do my first light pass, and then lower the bit to full depth and do the rest of the dadoes in one shot, all in a row. That way, they should be the exact same depth. I just gotta be REALLY careful about routing them in the exact same spots along the sides of the case as well, since I don't want any old material to remain.

Lesson learned. I'm also gonna get some slower-setting glue and make sure I do my dry fit WITH the clamps this time just to double check everything is perfect.
Near future projects:

-Curly Maple display case
-Jatoba and Quilted Maple dresser
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#28
My approach on things like this is "what can I do to turn a mistake into a design element?"

One idea would be to remove about 1/8" across the front of the divider, add a piece to fit. You could even put a dovetail on each end. A lot of work, but it would correct the problem.

Before cutting it apart, I would try using heat and a thin piece of steel to loosen up the glue (a narrow strip of card scraper or a putty knife cut down do 1/2" wide). As you apply heat to the steel, you should be able to tap into the joint as the glue melts.

Its just glued to the legs, right? If not, you'll never get it apart.
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