Thread: I need some advice on fixing a 60s chair.

I've done a couple of those. They always give way because people rock back on the chair.
I rout out the dowels and the dowel holes to make slots, then cut a floating tenon to fit snugly. Glue the whole assembly up with Techniglue rather than Titebond.

A bit un-orthodox but it worked. I did a similar repair on a 60s chair recently. The dowels in the chair I repaired were still good and not loose in one part of the job.
Fill the original holes for the dowels with Plastibond . If you have a case where the wood between two of the dowel holes is damaged as this one is, use filler in the whole of the damaged area. If all the wood between the dowel holes is damaged mark the site of the original holes with a pencil to guide you in the next step. Or consider the floating tenon repair as suggested above.
Hammer in some brad nails into the centre of each dowel , nip heads off at an angle with some side cutters so they each have a sharp point .
Locate the sharpened end of the brad nails in as centrally as possible in all three filled holes .
Give the doweled part a tap with a mallet thereby leaving marks from the brad nails on each filled areas of the original dowel holes.
Pull the sharpened brad nails out of the ends of the dowels.
Check the diameter of each of the original dowels, drill the appropriate diameter holes to the correct depth for the dowels .
Glue it up (I used Purbond).
Clamped the job up tight with pipe clamps for 24hrs. So far so good after 6 months of regular use .

AlexS is on the money with this one. Cant think of any better way to do it.
Dowels let it down in the first place so next time round with less well fitting dowels, well you see where it's going.
Regards
John

I also agree with AlexS, a floating tenon would be best.

Originally Posted by scottbr

For a friend, of course.
The chair is nothing special, but it's part of a set of four so they either get it fixed or look for a new set.

Given this I'd probably see if there's enough meat in the chair leg to make both mortises a bit deeper, so I could pin them with through dowels. For appearance sake, I'd probably stop the dowel holes short of the obviously visible faces and insert the dowels from the "inside" of the chair.

Then I'd just flush-cut the dowels and call the job done.

It's a pretty sure thing that this'd outlast the other rail joint if they keep rocking the chair back.

I hadn't thought of using extra dowels as suggested by Skew, but it's a good idea. Over their life, all chairs, unless designed so it can't happen, will have a levered load applied on the back leg-side rail joints that tends to pull dowels or mortises out. Dowels will help prevent this.

Glue rarely grips well to old glue, so you would have to scrape all glue off both the dowels and the dowel holes, thus reducing the former and enlarging the latter, and creating a sloppy fit. There is not enough meat there to replace the dowels with larger ones. This rules out dowels!

I think Alex's suggestion of floating tenons is a good one. However, I am not fixated on Techniglue - any good quality epoxy would do - whatever you have. My technique is:

• Dry fit everything to makes sure all is well,
• Mix up epoxy, stirring slowly and well,
• Paint absorption coat of epoxy on both the tenon and inside the mortise,
• Thicken the remaining epoxy - I prefer colloidal silica, but microfibres also works fine,
• Apply thickened epoxy, assemble joint and clamp,
• Immediately epoxy hardens, scrape off squeeze-out.

A dowel is just a round loose tenon!

Thanks all.
I was afraid I would be heading down the floating tenon path.
Still, it's something I have never done and there is a wet weekend coming up.
And I understand the logic of those through dowels. Might even have a go at them.
What wood should I use for the tenons?

I've always used hardwood, but as long as it's something reasonably strong that you get good adhesion with it shouldn't matter.

I make up long lengths of 10mm thick hardwood tenon stock in various widths. Most of it is Vic Ash. Any hardwood would work. I put a 10mm bullnose on the edges to match the diameter of the router bit that cuts the mortise. A shallow slot on each face allows excess glue to squeeze out.

A loose tenon is definitly the answer. In fact, it should have been used in the first place. I hate doweled chairs. If you really want to get fancy you can flare the ends of the mortice, saw cut the tenon to take two blind wedges, fit the wedges into the cuts allowing them to stick proud of the end of the tenon. When the joint is glued and clamped the wedges bottom out in the bottom of the mortice and are driven home by the clamping action.This, inturn, flairs the tenon edges into the flaired mortice ends which strengthens the joint considerably.

Originally Posted by rustynail

A loose tenon is definitly the answer. In fact, it should have been used in the first place. I hate doweled chairs. If you really want to get fancy you can flare the ends of the mortice, saw cut the tenon to take two blind wedges, fit the wedges into the cuts allowing them to stick proud of the end of the tenon. When the joint is glued and clamped the wedges bottom out in the bottom of the mortice and are driven home by the clamping action.This, inturn, flairs the tenon edges into the flaired mortice ends which strengthens the joint considerably.

Thanks. I understand exactly what you mean.
I don't want to get fancy.
Don't even want to do the job, to be honest.
It's a consequence of having a shed and some modest skills. Friends seek me out to fix things. I'm getting better at telling them up front what it will cost in beer rather than assuming they will do the right thing.
Scott

Originally Posted by rustynail

A loose tenon is definitly the answer. In fact, it should have been used in the first place. I hate doweled chairs. If you really want to get fancy you can flare the ends of the mortice, saw cut the tenon to take two blind wedges, fit the wedges into the cuts allowing them to stick proud of the end of the tenon. When the joint is glued and clamped the wedges bottom out in the bottom of the mortice and are driven home by the clamping action.This, inturn, flairs the tenon edges into the flaired mortice ends which strengthens the joint considerably.

Only for the brave!