Basic help....

[Bill Sullivan]

Hello and Best Wishes for the Festive Season.

I have tried to repair an old chair for my daughter and it has become 'unstuck'. See attached photo (Gravity assisted assembly) I know........... it's past it's use by date, but so am I.

I tidied up the joints as best I could and used PVA, allowing lots of time to reach full strength. Due to the shape of the piece, clamping was difficult. The chair design is not the best, (Says me...............) but it's a little bit old and my daughter wants me to try to save it. The arms, legs and horizontal cross members are only 40 X 20MM (1.5 X .75 inches) so limited in andding bolts etc (I think).

• Should I try again? (My daughter wasn't even slightly amused at being deposited onto her backside.)
  
• Throw it in the rubbish bin and accept that defeat is just another facet of life? (Hell hath no fury like the scorn of said daughter)
  

Your thoughts, practical, philosophical and/or amusing will be appreciated.

As you will already guess............. I am an old beginner.

Bill

[PaulMarcel]

That was probably one of those moments when you wanted to laugh, but knew you shouldn't

It's asking a lot for the glue to bear all the tension in the lower stretchers.

If you have some basic chisels and a hand saw, you could wedge the tenons. It assumes that the tenons fit snuggly in the mortises. If so, back-cut the ends of the mortises. Take a hand saw and cut straight down about 1/8" (3mm) from each far end of the tenon down to the shoulder line. It's not a bad idea to drill a 1/32" hole at the end of that cut just above the shoulder. Cut a wedge from some other wood; very narrow wedge about 2/3 the length of the tenon. Fat end of the wedge should be a hair wider than the kerf of your hand saw. Put glue in the mortise and tenon, put a wedge gently in each saw kerf, put tenon in mortise; you'll need to mallet it home at the end as that's when you are spreading the kerf with the wedge making the tenon wider than the mortise opening on the inside. You now have it mechanically strengthened as well as the glue.

Read up about them, too, or ask more questions here if you think this is something you want to try.

[Bill Sullivan]

Thanks Paul-Marcel. It sounds good to me, although I'm a bit rough around the edges with my handsaw skills. If I don't make a mess of that........ I think I will call into the hardware store and look for some steel 'T' pieces or plates that I can fix to the bottom joints (inner). It may not be pretty but given that the legs are sort of A frame (like so... / \ .....) I think, as you say, it's asking a lot of the glue.

Many thanks

I retire in February so I may have more time to improve my woodwork skills.

Bill

[Onboard]

Sounds like Paul-Marcel is talking about a fox wedged tenon (sometimes called a foxtail wedged tenon). You can do a Google search on those words and you should come up with some articles or videos showing how this works. You can do it as Paul-Marcel suggests or you can take a chisel and angle out the sides of the mortise a small amount to allow the tenon to angle into the sides when the wedges push the tenon sides outward from being driven into the mortise. This will make it much more difficult for the tenon to pull back out of the mortise. Don’t chisel the mortise entry (opening) any wider than it is. When completed the bottom of the mortise will be slightly wider than the top or the opening at the surface of the wood.

As you can see in the example the wedges will be driven into the tenon kerfs when the top of the wedges make contact with the bottom of the mortise while your hammering the assembly together with the mallet. This will spread the tenon apart against the sides of the mortise.

Here’s an example:

[Bill Sullivan]

Thanks for that. I think that even I should manage this.

[Mark Reuten]

Hi Bill,

I think you can get away with cleaning up the gluing surfaces with some sandpaper or a paint scraper. Re-glue with the pva or perhaps a heavier bodied glue like epoxy or polyurethane. Lastly, the tenons could be locked in place with something as simple as a finishing nail driven through the joint. Pre-drill to avoid mishap. No amount of clamping was going to help with that type of joinery so you only need to immobilize the chair while the glue sets. A bit of rope could do the job just fine. If you use epoxy or polyurethane, clean up squeeze out with alcohol before it sets.

[Mikejpt]

Well, clamping is the last step in getting the tight joints you want. The cheapest clamp for this type of glue up is an old (or new) bicycle tire cut into one long strip. Keep wrapping and pull down hard where the joints are. I a pinch, bungee straps work but watch the metal hooks.