Question about repairing a dining chair

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BuckeyeDennis
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Question about repairing a dining chair

Post by BuckeyeDennis »

My wife and I have a set of Amish-made cherry dining chairs that have gone through 18 hard years of child-rearing. They’re all getting loose, and some of the joints on the one my son had been using failed completely. I just took the failed joints apart as the first step in repairing them, and found a broken a wood screw going from the corner bracket (in the apron) into the back leg/stile. Undoubtedly from my son leaning back on it.

All of the apron members and the stretchers have tenons that fit into mortises in the legs. They appear to be well made, but the glue has failed completely. All of the tenons on the stretchers had been been pinned into their mortises with a finishing nail from an air nailer, presumably instead of clamping them up while the glue dried. Fortunately, the finishing nails bent like noodles when I pulled the loose joints apart. I can just clip them off inside the mortises and grind them flush with a dremel tool.

So here’s my question. The old glue in the joints appears to be PVA, and it’s a pretty thin layer. Assuming that the the joints still fit together properly, should I just reglue them with Titebond?

Taking off the old glue layers and re-gluing with epoxy would probably be stronger, but I’m not eager to invest that much time. Does anyone have a good repair method that’s reasonably quick & easy?
thunderbirdbat
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Re: Question about repairing a dining chair

Post by thunderbirdbat »

I would dry fit the joints, if the fit is good I would just re-glue. Loose joints I have seen thin wood curls from a plane added around the tenon to take up some of the space in the joint.
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algale
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Re: Question about repairing a dining chair

Post by algale »

If you add PVA glue over old PVA glue without sanding the old glue away, you will be doing this project again very soon.
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Hobbyman2
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Re: Question about repairing a dining chair

Post by Hobbyman2 »

I agree just my .02

here is a article on chair repair glues .
http://www.woodmenders.com/glue-furniture-repair
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BuckeyeDennis
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Re: Question about repairing a dining chair

Post by BuckeyeDennis »

Thanks everyone. Brenda, it had never occurred to me to use hand-plane shavings for shims, but that's a neat idea.

Al & Hobbyman, I did a little more internet research, and the most credible sources I found shared the belief that almost nothing bonds well to dried PVA glue -- including PVA glue. One guy had some test results to back this up. He has done a lot of furniture repairs repairs, and considers PVA-glued M&T joints to be non-repairable, short of a complete M&T rebuild. The link below has the details.

https://sawmillcreek.org/showthread.php ... Repairable

There's no sign of broken wood fibers on my failed joints, which makes me doubt that there ever was a good bond. I also found some sources indicating that PVA joints must be kept clamped securely while the glue cures, or else movement during curing will make the glue joint fail. All of which is consistent with the finish-nail pinning that I found in the stretcher joints.

So I'll study the old glue a bit more, in hopes that it's not really PVA glue. If it is, I see my options as:
1. Sand/grind/chisel both the mortises and the tenons down to bare wood, and re-glue using shavings and/or gap-filling epoxy.
2. Draw-bore the M&T joints, so that the glue bond is unimportant.
3. Dispose of the chairs.

Option #3 is probably the most likely. That particular table & chairs set needs a lot of TLC -- this is just the most acute problem. And if we pull the trigger on some kitchen remodeling that my wife wants, we'll have neither the need nor the room for them anymore.
charlese
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Re: Question about repairing a dining chair

Post by charlese »

I recently repaired a set of oak chairs that served my kids and grandkids for many years. DIL said "get them out of here before someone gets hurt". I took them and me and my shopsmith repaired them so they are again welcome in her house. They've been performing well for the past 5 years or so.

I replaced all mortice and tenon joints with new and larger dowels. Just needed re-boring, dowel turning and clamping. Used Titebond yellow, but after thought was maybe should have used animal glue making it easier in the future to remove joints and re-glue, if needed.

one of the hardest parts of this repair was to break apart joints that were still firm. Had to use a spreader clamp.
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