Things (Chairs) Fall Apart

 If you build furniture and especially chairs, at some point you will be asked to fix something.  It's not a matter of if, but rather when.  In this case an old, heavily built pine chair collapsed.  The tenon into the seat snapped off and down she came, breaking off another couple tenons in the process.  Things fall apart, the center cannot hold. 

 In this case, I was lucky in that they were clean breaks, no long jagged splits.  Of course the question is whether or not the fix is worth it must be considered.  I leave that up to the them, but usually the piece has far more sentimental value than monetary, but at any rate, every fix is different and often the hardest decision is where to draw the line.  This chair was actually in pretty good shape, and with such clean breaks I proceeded as follows.
First off, I cut the leg off, and using the lathe and a drill chuck, I drilled out the hole and inserted a 5/8 maple tenon into the hole; this becomes a new tenon.  I use epoxy for most repairs like this one where to original glue was PVA, carpenters glue.  I should say here that for all it's good properties, carpenters glue will not bond to itself once it has cured.  It has to be scraped completely off to wood, and reapplied.  This is why I use epoxy.    Be sure to abrade the surfaces with 40 or 60 grit sandpaper, and make sure the fit is kinda loose, not sloppy, but not tight.  Also, thicken the epoxy with sawdust or a product sold by West System, silica dust.

  Like I said, I like West,  and they have a great boat repair manual you can get thru Lee Valley.  I use the high density filler.  Be sure to wear a dust mask, it is silica and can damage your lungs.  I mix it to about peanut butter thickness, maybe a touch thinner than that.

 Here you can see (hopefully) the epoxy smeared into the hole (mortise).  Put plenty in there, you don't want a starved joint.  And try to abrade as much as possible.

 This is where the leg goes into the seat.  Again, plenty of glue on the tenon and in the hole.  Since this is a blind hole ( it doesn't go thru the seat) when you drive the leg in, you will get hydraulic pressure sufficient to prevent proper seating of the leg.  So I drill a small hole that intersects the leg hole.  You can see the tip of the awl in the hole.

 And when the leg is hammered or clamped into the hole, you can see the excess glue coming out the relief hole-- this way the leg will go into the seat all the way.  If you don't drill the relief hole, the leg will sort of go into the hole, and when the clamp is taken off, the leg will move back out of the hole.  This can be very frustrating if you don't understand and know the solution.

Here is the chair with the repaired undercarriage.  I did clamp it up; the legs to the seat and a couple clamps on the stretchers for good measure.  The epoxy I use takes awhile to cure but it does work very well.

 This Sack Back below has a lot of great qualities.  The hands are great,  I will try them on a C-arm.  The turnings are lovely and the overall proportions are very nice.  For a factory chair it is a really nice chair.  The paper on the underside of the seat states it's based on a chair from Monticello.  Unfortunately, the seat has split right in half.  I've had this chair for awhile now, and while I like the chair, it will be a tough fix.  I could just epoxy the split and hope for the best, but I'm not sure how long that would last.  Tough call.  Things fall apart, the center cannot hold.  In this case, literally.