It's 2023 so we have 20 screws loose...

April 26, 2023 5:05 PM

How do I get the bolts attaching the legs to my dining chairs to stay put??

Recently bought new dining chairs -- they are a padded fabric "upper" with metal legs. The legs are formed by two metal "u" shapes that cross over in the centre and attach to the bottom of the chair. In total there are 5 bolts and washers per chair (one pair per corner and one in the centre where the leg "u" crosses). The bolts are screwed vertically into the chair bottom. And every single day they come loose and we have to tighten them.

I know there is Loctite and similar thread locking adhesives, but would that work in this scenario where most of the materials are metal (I mean, I know the bottom of the chair is not metal -- I don't know WHAT it is but I guess probably some sort of composite)? Every similar question I see posed is about the bolts in a corner brace of a wooden chair, so I don't know if this solution would apply to my chairs. I also don't know if using Loctite or similar means the bolts can NEVER be removed. Are there any other solutions to ensure the bolts stay tight? Spells? Incantations?

posted by Mrs. Rattery to Home & Garden (11 answers total)

Best answer: Loctite works on metal just fine - it locks the threads of the bolts to the threads of the nut or the threads of whatever the bolt is screwed into. There are different grades of Loctite, blue is meant to be removable with basic hand tools.
posted by soundguy99 at 5:13 PM on April 26, 2023 [14 favorites]

Can’t add much to soundguy’s answer - it’s the right one. I recently did this to some dining room chairs it worked great.
posted by bitdamaged at 5:28 PM on April 26, 2023 [1 favorite]

Loctite works best for things that aren't being jostled as much. I think it will slow down the loosening maybe once a week or two, but not stop it, and then you have to reapply. Are all the washers split/spring lock washers? If not, I'd go buy a handful of those from the local Ace hardware or similar. Bring the bolt to be sure it's right.

Lock washers also aren't perfect, they rely on increasing friction and they also allow things to work loose, hopefully more slowly. There is an extra fancy type of lock washer called Nord lock that is much more effective because it is based on tension between two different wedged washers that resist rotation even when the bolt isn't very tight. I use these on a bolt that acts as a the pivot for my bike trailer hitch and even with lots of turning, the bolt stays snug!

Better washers can of course be paired with locktite for maximum stay-puttedness.
posted by SaltySalticid at 5:37 PM on April 26, 2023 [3 favorites]

Loctite is certainly what I would try first. It's not quite superglue -- it will be possible to unscrew the parts with some effort.
posted by Tell Me No Lies at 5:42 PM on April 26, 2023

Loctite works best for things that aren't being jostled as much.

I normally try not to argue on ask, but Loctite was invented to prevent bolts from coming loose from vibrating machinery. Outside of industrial settings the most common place I've seen and used it is on bicycles and cars.
posted by bitdamaged at 5:47 PM on April 26, 2023 [4 favorites]

Although I will warn that loctite is primarily intended for metal on metal and can do unpleasant things to plastics, so it depends on what kind of composite the seat is. I don't think it's problematic for wood (i.e. stuff that might appear to be a composite like MDF), but I don't think it's particularly useful either. I guess it depends on what kinds of screws they are into what kinds of fasteners. If the bolt is screwing through the leg into a metal captive nut in the seat base, then absolutely, blue loctite is your pal. If it's screwing into the wood directly, you've probably wallowed out the "threads" in the wood and wood glue and toothpicks are a start to rebuild the joint.
posted by Kyol at 6:07 PM on April 26, 2023 [1 favorite]

Best answer: The seat base almost certainly has 't-nuts' that the bolts screw into. Because they have metal threads, Loctite will work fine - preferably blue because the red version is permanent and you might want to take them out one day. You may be able to confirm the presence of t-nuts by peering down the bolt hole with a light source.

Assuming there are t-nuts or some other method of providing metal threaded holes present, I have to wonder if you are not tightening them up enough. It's not usual for fasteners to loosen on a daily basis. Adding spring lock washers would be a good idea and, really, should be sufficient on their own, assuming the bolts are tight enough. Don't just assume there are metal threads in place - do the look-down-the-hole thing first as, if they're just screwing into plastic threads or something, Loctite and tightening them up more will both make things worse.
posted by dg at 6:16 PM on April 26, 2023 [2 favorites]

I had a similar problem with some chairs and applied Loctite a couple of months ago. Haven't had to tighten them since.
posted by any portmanteau in a storm at 6:35 PM on April 26, 2023

Can you replace the washers with lock washers? You can probably find them at a hardware store for a buck or two.
posted by Slinga at 7:07 PM on April 26, 2023

I'll clarify that I've personally had loctite jostle loose in situations where the good lock washers solve the problem. I'm not saying it for sure won't work, I'm saying the Nord lock washers are better. They were also invented for industrial applications under demanding circumstances, and so would be a good next line of action if the loctite isn't working well enough.
posted by SaltySalticid at 7:58 PM on April 26, 2023

Response by poster: Thanks all. Seems like I will try a one-two punch of getting spring lock washers and some blue loctite.
posted by Mrs. Rattery at 4:30 AM on April 27, 2023