Fixing a poorly designed chair

[Mjward]

Unfortunately I am the owner of 15 Dunelm chairs of poor structural design. They are constantly wobbly no matter how often I tighten them.

Essentially the wooden chair leg/pole fits inside a metal sleeve and held in place by a single fairly short bolt. The metal sleeve is then affixed to the chair base by 3 further bolts. There is no issue with the metal sleeve moving, only the chair leg wobbly within the sleeve.

What are you suggestions for a tighter/more solid fit that stops leg movement? Wondering if it's a longer bolt required?

 

[Sandyn]

First thing I would try is using a cross dowel in the leg to hold it firmer in the bracket. If the leg doesn't fit well in the bracket, I would use some two part wood filler to ensure the leg is seated in the bracket properly.

 

[Inspector]

Good epoxy. Not the 5 minute stuff.

Pete

 

[Bingy man]

Good epoxy. Not the 5 minute stuff.

Pete

To echo sandyn a dowel inserted into the legs to expand the tube slightly and as inspector says decent epoxy before tapping legs back into sockets. If I read your post correctly the sockets fixed to the chair base and are not the issue. As you say poor design so either the legs or the sockets are not strong enough for the job there doing as from you pic there are no cross members to support the legs ..

 

[Inspector]

The reason I suggest epoxy is that with time the legs have possibly dried somewhat since they were made loosening up and "large people" plopping them selves into he chairs over the years will have compressed the fibres of the wood in the sockets also loosening the legs. Epoxy will fill the gaps and unify the leg and socket so they can't move, for a few years anyway.

Pete

 

[Mjward]

Thank you!!! Have watched a few videos on both the cross dowel and epoxy and seems this is exactly the fix required. Will get the parts and report back with an update

 

[Mjward]

Couple of questions...so disassembled one of the leg to remind myself of the setup and... although bracket bolted down, leg is screwed into bracket.

I'm thinking given how short the screw is, would a longer and thicker screw provide a significant benefit or should I jump straight to bolts and cross dowel?

Either way, what's the approach to core out the existing hole keeping the bit central? Was thinking pillar drill but it wouldn't have the height to fit the leg vertical between drill and base.

Finally, looking up epoxy I've been swamped by choice, is there a particular product you'd recommend for this situation?

Thanks in advance

 

[rafezetter]

I think Epoxy is still the best way to go - though you'll probably be unable to remove leg from socket ever again. If that is a concern then smear some paste wax, vaseline, candle wax, 3in1 - whatever you have to hand inside the socket before adding epoxy, so the epoxy just fills the excess space, but doesn't bond to the metal. Wrap some masking tape over the first part of the top of the leg that isnt going in the socket to carch epoxy runs.

You could add a longer screw so that it has fresh wood to bite into which would help, though I'm not sure a fatter screw would do much as I don't think the wood around it would flex enough; if you have some, a coarse single thread screw would be best, and try to reuse the old thread in the wood instead of making another as that also weakens the strength.

Basically turn the screw backwards slowly until you feel the tip of the screw "drop" into the old thread - hard to explain but you'll know it when you feel it. It's always best practise to do this when undoing and then reseating screws, otherwise you'll cut new threads over the old ones and after 2 or 3 times the wood is just mangled and has no hold on the screw threads and will have to be dowelled.

 

[Mjward]

Agree with you re effect of filling the gap with epoxy. Upon closer inspection there is a good few mm gap between the end of the chair leg and where the screw starts to engage from the bracket. Almost big enough for me to wonder if adding some wooden discs to give the screw more purchase/compression between the leg and the bracket.

When I search for epoxy and wood I seem to be inundated with the gorilla glue 5 min stuff but not finding anything more suitable

 

[Bingy man]

Couple of questions...so disassembled one of the leg to remind myself of the setup and... although bracket bolted down, leg is screwed into bracket.

View attachment 133697

I'm thinking given how short the screw is, would a longer and thicker screw provide a significant benefit or should I jump straight to bolts and cross dowel?

Either way, what's the approach to core out the existing hole keeping the bit central? Was thinking pillar drill but it wouldn't have the height to fit the leg vertical between drill and base.

Finally, looking up epoxy I've been swamped by choice, is there a particular product you'd recommend for this situation?

Thanks in advance

Your photo above shows some type of adhesive previously applied to the leg , as you don’t have a lot of wood to play with im wondering if adding cross dowels might actually weaken the remaining wood . If the previous glue or epoxy or whatever it is , can be removed why not try cutting a suitable diameter steel tube and then tap over the leg ends . Longer screws using a small pilot drilled into existing hole and the steel sleeves will help prevent the ends from splitting- the legs now sleeved can be tapped back into the brackets creating a tight fit-you could still use epoxy to glue the steel sleeves to the leg ends . The wood used for the legs will have less chance of wearing again. Axi do some decent epoxy-5 mins and 30 mins..

 

[AES]

I'm wondering where the "real" problem is! Clearly the leg is wobbling a bit in the socket, but how long are those 3 screws on the "socket plate"? How much clearance between the shaft of those 3 screws and the 3 holes in the "socket plate"? How tightly do those 3 screws tighten into the base material of the chair?

I'm not sure I like the idea of the cross-dowel myself - it will not only look unsightly (IMO) but will not - I think - add all that much strength to the joint, because the stub that goes into the socket is, IMO, too short, especially if there's a bit of a gap between the OD of the socket and the ID of the socket.

If they were my chairs I think I'dproceed as follows:

1. Double check that the 3 screws going into the chair are a "tight" fit into the "socket plate" holes, AND that the 3 screws are the correct thread (Fine or Coarse? What's the base material of the chair body?), AND of the correct length to go fully into the chair body (without coming through into the seat itself of course!);

2. Drill for a captive nut to go into the TOP of each chair lag stub; PLUS add a suitable length C/S bolt into the UNDERSIDE of each socket plate. Double check the length of each bolt such that it engages fully into the captive nut, AND check that there's enough "free hole length" beneath the captive nut to ensure that a) any excess epoxy has somewhere to go while assembling, and b) there's absolutely no interference between the bolt and the hole inside the stub/leg;

3. Use "good" epoxy (my personal favourite is the "standard" Araldite - NOT the quick set stuff);liberally coat the stub of the leg and, according to how tight a fit it is into the socket, perhaps also the inside of the socket with epoxy. Then (BEFORE the epoxy has set of course!), screw the leg firmly home all the way into the socket and leave to dry undisturbed for at least 24 hours;

4. Only after the above 24 hours do you use the 3 screws to screw the complete socket plate/leg assembly onto the chair.

HTH, I'm pretty sure the above will work well, even if a bit more long-winded than some of the other solutions suggested above.

Yes, if at any time in the future you need to remove a leg from its socket that's going to be rather difficult, but another possible advantage I see in the above bolt into captive nut idea is at least you have SOME chance of "unscrewing" the leg from the socket.

 

[Inspector]

Your said you problem is loose legs. A cross pin, bolt, screw etc would only keep it from coming out, weakening the joint, not stopping the wobble. Clean off most of the old glue with a file, rasp, sandpaper and re-glue with the Araldite or similar epoxy. Use the same screw again because using a bigger one can make the leg spit.

Pete

 

[rafezetter]

Your said you problem is loose legs. A cross pin, bolt, screw etc would only keep it from coming out, weakening the joint, not stopping the wobble. Clean off most of the old glue with a file, rasp, sandpaper and re-glue with the Araldite or similar epoxy. Use the same screw again because using a bigger one can make the leg spit.

Pete

Pretty much as I said, but I think he could get away with a longer screw of the same diameter to give more purchase on the leg, just hand tight and no more. If the epoxy is applied generously then it will fill the gap at the top, and when you add the screw dip the screw in some 3 in 1 oil or spray with wd40, or rub it on a candle - basically something to prevent the epoxy from afhering to the screw so it's removable if that's what you want - though to be honest if you ever needed to take the legs off you can do that via the 3 bolts on the underside of the socket plate, so gluing the leg in with the screw also glued in place is no big deal.

AES idea does have merit, though I'm not sure the OP has the skill level, otherwise he would not be asking for advice about this, and I would use a shim made of soda can aluminium rather than a steel rod, as it's much easier to come by and can be wrapped around the top of the leg to the suitable thickness required, then the leg hammered in tight.

 

[Mjward]

Thanks all. Brilliant to have so many options and it seems like a clear plan of action ahead. Will get the recommended epoxy and look at the captive nuts and hopefully get them all sorted this week will update with results

 

[Mjward]

Put together a test leg today, will be cured tomorrow but already fills significantly more stable with just the longer screw so can only get better when the resin sets

 

[thetyreman]

definitely a cross pin, brass or mild steel say 2mm doesn't have to be big, and then peen it combined with epoxy, that's unlikely to ever come out again.

 

[spanner48]

I would suggest:

1: Cut off the eroded stub end that's been in the joint with the steel bracket; profile the next - say 50mm to a tight sliding fit in the bracket.
2: Mark where the leg slides through and butts up against the seat base. Drill that out half way through at the same diameter.
3: Offer up the leg to both the bracket AND the seat pan. Check it's tight sliding fit in both.
4: Fox-wedge the top of the leg with a hard [oak, box, teak, meranti etc.] wedge, long enough for the full depth of the insertion.
5: Add slow-set Epoxy to inside of bracket, seat pan, leg stub and wedge.
6; Use mallet to knock it home

Should tighten up quite a bit . . .

 

[Mjward]

Have got 4 chairs reassembled using the epoxy/longer screw method. They are a nice snug fit particularly with added resin between end of leg stub and metal bracket ie wrapping around the screw as it goes in too. Plan is to stop at 4 and trial them for a few weeks. Based on those results will either continue or try some of the other suggestions with the remaining 11

 

[Inspector]

I would suggest:

1: Cut off the eroded stub end that's been in the joint with the steel bracket; profile the next - say 50mm to a tight sliding fit in the bracket........Should tighten up quite a bit . . .

So you are okay with all the chairs sitting a couple inches lower? You'll end up having glorified milking stools with backs.

Pete

 

[spanner48]

It only looks like about 3/4". Don't that that would be too noticeable.