Hairline crack in chair leg socket

[terry.shitcrumbs]

Hello all. I have an antique oak dining chair with a wobbly leg. The leg is fixed to t he chair base with a peg and socket arrangement- the peg being a whittled e nd of the leg and the socket being a hole in the seat frame. The design of the chair is such that the leg has no attachment to other legs (i.e. it sim ply projects from the seat base).

I have pulled out the wobbly leg (it needs replacing anyway) and while doin g so, I noticed a hairline crack running across the square section, end gra in frame part into which the peg ,on the end of the leg, inserts. The crack runs across the socket and I would guess that a poor fit of peg in socket and the associated movement might have caused this to occur.

Before fitting a new leg (making sure a snug but not over-tight or excessiv ely loose joint is created), I need to fix the hairline crack. What I need is a very low viscosity glue that sets hard as hell and ideally, that can b e force-fed into the crack. One notion I had is to drill a tiny (1mm) hole into the crack, pry the crack open as much as I dare, without splitting the wood further, then squeeze a load of super glue into the hole. Once the gl ue is in, I would clamp the crack shut and leave to dry.

So, is the procedure described above a sensible one, or should I start with something different?

Thanks.

Terry.

[Tim w]

I have done a bit of restoration. liquid epoxy resin, with plasticene and tape to keep it where you want it. It isn't easy to control. It isn't easy to put right if you get it everywhere and it hardens.

Maybe epoxy the leg into the socket while you are at it.

Epoxy is super strong but won't accomodate any wood movement and can really complicate subsequent repairs so not always recommended on valuable antiques, but fine if it's just a nice old chair you would otherwise have to chuck out.

The purist repair might be to use honest and brutal antique techniques. Like a couple of large nails angled throught the joint, and a wooden peg across the crack.

Tim W

[Dave Liquorice]

Good description but no where near a thousand words, a picture or two would be useful. Upload to tinypic.com and post the direct URL of the image file.

It sounds as if the crack will be in tension, not many glues are good in tension and even if you use one that is the timber can still fail and the crack just move slightly to the side of the orginal.

Can you get a screw across the crack? Counter sink/bore a little for the head and fit a matching wooden plug to cover it?

[Ian Jackson]

In message , Tim w writes

Epoxy resin is indeed an obvious choice - but it can be a bit viscous for very small cracks. It flows better if you warm it up - but don't add much hardener, or it will go off too quickly.

Alternatively, superglue* readily penetrates cracks and porous materials, and sets very hard. You might need to keep topping it up as it soaks in.

• When buying, I would recommend getting large tubes. B&Q do a 20g bottle (for around £7?). It lasts for ever, and I have had few of the usual problems you get with the smaller tubes, where the second time you use it, you find that the cap is well and truly glued on.

[The Natural Philosopher]

This is the WORST advice I have ever seen on UK.d-i-y.

Epoxy is designed as a two part mix and MUST be mixed *thoroughly* in the exact proportions specified (generally 1:1 for an amateur epoxy) or it will *never set at all*.

If you must use it and need it runny, choose a 24 hour set one, mix it as advertised, and heat the mixture.

Possible a better idea would be a *polyester* resin which DOES take a catalytic hardener.

However what is really needed is a glue that penetrates the wood as the tensile strength of wood parallel to the grain is pants.

Previous advice to use a screw is good advice, Even drilling a hole and putting in a wood peg coated with PVA and clamping up, is better.

I've used so many solutions to this generic problem in model plane building and none of them work - in the limit the glue bonds OK but simply rips the top layer of fibres off the wood. (the classic case is a wire undercarriage bonded to a ply former) Binding the wire to the former with kevlar thread works, but then the former rips out of the fuselage in a hard landing. Opinions are divided as to which is preferable ;-)

I think in this case I would really be looking at a screw counter-bored plus (PVA) glue, to draw the wood back together, and then a decorative bit of oak plug inserted in the counter-bore to cover the screw head, stained and finished to match the rest of the chair.

[Capitol]

Just glue the leg into the socket. The bond length will be the circumference of the peg + the end cross sectional area and the load will be distributed. Filling the crack is IMO a waste of effort. Something like Cascamite? will do a good job.

[Dave Liquorice]

+1 but at some point the glue won't have pentrated and you're back to plain, weak, wood.

Yes, I forgot the glue bit stops things moving about. PVA will do but as the OP pointed out it mich be tricky to get into the crack. I generally prise gently prise open the crack slighly and use a bit of paper or thin plastic (the rigid clear stuff used for windows on some box packaging to work glue down.

Or stolen with a plug cutter from a hidden part of the same bit of timber. Perfect match then. Still waiting to use the set of plug cutters I got from Aldi a while back ...

[Ian Jackson]

Of course, I WAS thinking of POLYESTER resin!

BTW, does the amount of hardener have much effect on its final hardness? I've always assumed it doesn't (unless you use ridiculous amounts of hardener).

[Bob Minchin]

Use Chair Doctor?

One supplier of many

[terry.shitcrumbs]

This seems like just the ticket. Great, thanks! Other replies appreciated, too. Terry.

[Roger Mills]

You beat me to it! wonderful stuff.

[newshound]

You both beat me to it, ISTR that it's also available via Amazon

[Brian Gaff]

I've never found Superglue and wood very matey myself. You almost need some kind of epoxy I'd imagine. I had a chair die as mentioned but although it was old Antique or valuable it was not. I used araldite but it only lasteed about a year or so.

What you have to remember is that if the leg is not supported at all other then this socket, its got to be bloody strong glue! Brian