Repairing a captain's chair

I have a captain's chair (I think that's what it's called?)...

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as you can see has a strut between the legs which has come adrift. I've tried glueing it back, but the legs have become slightly splayed, so with my weight on the chair with the strut glued, the strut is in tension and it pops out again (the ends are not particularly snug fits anyway.

I could probably solve this by putting an axial screw in either end of the loose strut, through the side-struts, but this isn't how the chair was made and I feel that would be rather a bodge. Any suggestions on how to do it properly?

BTW the tops of the legs are embedded in their sockets in the base of the seat; they are firmly stuck although there's a bit of lateral play which I know I need to lose.

Thanks David

Reply to
Lobster
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If 'Resin W' won't do it I don't know what will. That stuff is stronger than the wood.

Reply to
brass monkey

Lobster,

To give a permanent repair:

Try cutting a slot in either end and fit a suitably sized, 'secret' wedge to the depth of the mortise (as in a mortise and tenon, secret wedged joint) so that when it is fully in the mortise, it expands the ends if the rail just enough to grip [1], clean off *all* the old glue, tap the wedge into the end to start it, glue up the rail ends and insert - giving side rails a sharp rap with a mallet (and a scrap piece of wood as a protector) until the wedge is driven fully home.

[1] You could taper the mortise slightly from top-to-bottom (bottom obviously wider) to form a sort of dovetail thus giving an even better grip when the wedge is driven home.

Cash

Reply to
Cash

Get some PVA and mix it with a fair bit of saw dust and glue the strut back in place. When the joint is dry drill from underneath and fit a glued dowel to pass through the stut, but not right though the bit I can't remember what it is called, but the strut joins up to. Dont use too large a dowel, you are only preventing it from popping out. The important bit is the filler in the loose strut joint.

End screwing wood grain just doesn't work, so I would forget that idea.

Dave

Reply to
Dave

A variation on the sawdust and glue...

I have used a plane (real one, not electric) to generate a shaving which is the right thickness to make up for any play in a dowel-type joint. With the plane, you can adjust the cut to get whatever thickness shaving you need, to make a tight fit (which you also glue).

This has worked very well on the banisters I built - the acorns (or balls in my case) on top of the newel posts get a hell of a force on them when everyone swings on them where the stairs turn 180 degrees. I knew they'd quickly come off it they weren't very secure, and they've been firmly attached this way for probably 8 years now, with no loosening whatsoever.

Reply to
Andrew Gabriel

Nice chair!

As a variation on all the other suggestions, clean up the joint and stick it back together with a liberal dose of Gripfill - obviously cleaning off any bits which ooze out, before it sets. Leave it a couple of days before sitting on the chair.

[I always thought that sort of chair was called a 'carver' BICBW].
Reply to
Roger Mills

Yes, any movement at the tops of the legs will be amplified at the position of the strut and will just make those joints fail. You probably need to strip clean and reassemble the entire legs/struts for the chair. Ensuring that you have to tap each joint together on assmebly. Secret wedges are good but I can imaging tricky to get right so that the expansion is just right with the joint fully home. I quite like the planing shaving idea but not sure you could have a good tight physical joint without the shaving being displaced.

Reply to
Dave Liquorice

There is a glue designed just for this problem, never used it myself but..

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blurb says;

----------------------------------------------- Veritas Chair Doctor Glue

Chair Doctor Glue does exactly what the name implies - it fixes chairs. If a chair has a loose rung an injection of Chair Doctor Glue will first swell the rung and then bond it in position. The secret is the low viscosity. It soaks into the end grain, swells the wood then 'freezes' the wood in its swollen state as it cures. A film of dry glue is left on the walls of the wood cells preventing contraction. The glue can penetrate the narrowest of cracks and is supplied in a bottle with a micro dropper applicator tip which lets you place the glue accurately. For regular cabinetmaking PVA adhesive is the best choice; but for fixing loose joints where disassembly is not an option Chair Doctor Glue is the most suitable. Available as a 57ml(2fl.oz) bottle or the Pro Kit which contains 114ml(4fl.oz) of glue, syringe and three different injection needles.

------------------------------------------------

Reply to
The Medway Handyman

You should always split the end of legs and wedge, for an intersting reason.

Variations in humidity will cause cross grain wood to move more than it does along the grain.

Therefore when dowelling into wood that has one dimension along the grain, you need a cut in the dowel perpendicular to the grain direction of the seat (say).

Then as the dowel expands and contracts it wont tear the glue free. wedging is optional, but no bad idea.

Reply to
The Natural Philosopher

It's broadly a Windsor (because the seat is a single plank), or more specifically a Carver because it has arms.

John Carver was one of the first settlers on the Mayflower and became Governor of New Plymouth. His magistrate's chair survives today. This might not have been the first Windsor with arms in this style, but as one of the best-known early examples in the USA, it gave its name to them.

Captain's chairs are usually revolvers and don't have separate arms & back, Instead they have a semi-circular gallery all the way round, often with a padded backrest above this:

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...which as you can see has a strut between the legs which has come

Chairs are one of the hardest bits of furniture to make structurally, and they're worse to repair. Lots of stress, dynamic racking stresses not just weight, and thin section timber to do it with.

I'll be blunt - your problem here is the cheap crapwood used to make them, and the stuff isn't hard enough to make a load-bearing tenon that doesn't wear smaller with any fretting loads on it. The real fix is better made chairs, better-fitting tenons, made of better timber. A genuine green Windsor is assembled by differential shrinkage (the tenon is dry, the mortice is green and shrinks to grab tight hold), no glue or nails and should last 50 years.

So any attempt (like Veritas Chair Doctor) that assumes a well-fitting joint in strong timber isn't going to work - the timber's not up to it. So do something else instead. Don't use foxed wedges (i.e. secret blind wedges) as the tenon will still chafe and they'll come loose. Also foxed wedges are considered bad workmanship as they can't be dismantled for repair in the future.

So what's left? Epoxy is one. Use a good low-viscosity resin (West System) and thicken it yourself with a filler like phenolic microballoons to "peanut butter" consistency. Don't use Araldite. This is a good option for really damaged tenons, but it's a one-shot fix. If the chair wears loose again, you'll not get it apart for a second repair. For that reason, you need to fix _all_ the loose joints in one go.

Another option, commonly used to make this sort of chair nowadays, is to bolt it together with barrel bolts.Drill axially along the rail and out along the mortice too. Drill crossways halfway through the rail and insert a cylindrical barrel nut. This is also tightenable in the future.

Reply to
Andy Dingley

Spotted the cable going to the back of it, so I reckon it's an electric chair.

Reply to
Old Git

Heh. Wondered if that would raise any eyebrows!

FWIW it goes to an electric pencil sharpener. (Yeah, I know, and I didn't buy it....)

David

Reply to
Lobster

Bummer - I though that chair doctor stuff looked just the job!

The tenons aren't actually badly damaged, they're just slightly loose now. I can see that the barrel bolt idea would do the business, but had thought drilling visible holes etc would be rather a bodge in itself - perhaps I'm being a bit precious about it though since it's not a particularly old chair and apparently made of crapwood ;-) (although I'm quite fond of it!).

If I used resin on it, if that repair failed subsequently wouldn't it be possible to 'convert' to the barrel nut/bolt repair just by drilling the necessary holes straight through any assembled joints (IYSWIM)?

David

Reply to
Lobster

Yes, I think that would probably work, in extremis.

Reply to
Andy Dingley

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember Lobster saying something like:

Tell the Captain to lose a bit of weight, the fat bastard.

Reply to
Grimly Curmudgeon

Just revisiting this thread in the hope that Andy's still watching...! I don't know much about these resins, and efforts to locate this West System stuff have only led me towards boat-building quantities. What's the problem with using Araldite, which I *am* at least familiar with? If that's not appropriate, is there a suitable readily obtainable alternative?

(BTW forgot to mention in my OP that my original failed attempts at repair had involved a gripfill-like adhesive (I forget which brand).

Thanks David

Reply to
Lobster

Axminster. They sell a "handy pack" (10-15 quid) that's a good workshop size and enough to keep the workshop going for about the shelf life of a bottleful. Get a few of the filler materials too, they're useful and not expensive. If you aren't sticking fillers into your epoxy, then you're only seeing half of its uses.

There are three problems with "retail tube" epoxies:

  • They tone down the toxicity of some of the resin chemistry. The liquid stuff is a bit more unpleasant, but works better.
  • Viscous tube epoxy isn't such a good resin system either.
  • You can thicken liquid epoxies by adding fillers, but you can't thin an already-viscous epoxy for those jobs where you want it thinner, fibrous or sandable.

If it's all you have, use the Araldite. But good epoxy is a whole new toy to play with in the workshop and worth seeking out.

Reply to
Andy Dingley

I can assure you that epoxy is not a good glue to use on wood.

I use it a LOT with glass cloth to bind metal struts to ply formers: Under stress it ALWAYS tears off the wood. It simply does not penetrate the way e.g. ordinary white glue does, not does it have the flexibility.

After trying just about everything including foaming polyurethane glues, I have dome back to good old cheap PVA' white carpenters glue.

As I said way back when, the secret to wood work joints is to understand that wood expands and contracts far more across the grain than it does along, so a joint that wont split out and work loose needs a slot in the tenon part *across* the grain direction of the wood into which it fits.

Then a good accurate fit and it should stay tight with PVA. Alternatively the foaming polyurethanes are flexible and good gap fillers, but even those have cracked up when faced with drying green oak joints :-)

Funnily enough old fashioned glue pots - or the modern alternative - a hot glue gun - are a lot better than most people think. Thats teh final alternative I would suggest.

Must get one meself...fed up with borrowing me mates..

Reply to
The Natural Philosopher

Then you are using the wrong epoxy.

_ALL_ wooden boats built these days use epoxy (well I suppose there may be some luddites out there trying to keep the old ways alive). Mine's been raced for 10 years, and the joints are perfect.

If the OP wants to try it, something like this

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contains all the right bits. Whether it's worth it for an old chair is another matter.

Andy

Reply to
Andy Champ

Ply?

do you crash them? Bend Them?

Chairs get a LOT of stress.

And ply doesn't move the way ordinary wood does.

Reply to
The Natural Philosopher

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