Any tips on plastic adhesives? Trying to repair headphones
Hi DIY!
My headphones of many years recently broke. My first response was to attempt to glue them back together with super glue (ethyl 2-cyanoacrylate) however that didn't seem to hold. Not even a little bit.
I then did a bit of searching and found that Sony often use ABS plastic in headphone manufacture, so presumably these are ABS. I then read super glue should work okay on ABS, however there seemed to be no bonding happening at all.
Do any of you have any tips for the best kind of glue or epoxy to bond these plastic parts back together and get the music flowing again?
I plan on wrapping the joints in thread afterwards, for additional durability. But first I need to get them bonded.
87 replies
I would make some metal rods to insert in the holes left in the hollow plastic. Epoxy those in place on both sides to reinforce the joints which will have stress on them. I think that is the only chance you have of repairing broken plastic like this with little surface area to bond. You could look around and find some nails or something to cut up.
Great idea! I'll give that a go, thanks. Reinforcement rods, adhesive, and thread wrap around the outside should surely be enough
Might be able to find some wire in an electrical or automotive store. 20 guage is about a millimeter or less, 12 guage is between 2 and 3 mm. Do you have calipers to take a measurement?
Wire Coat Hanger might fit, will be harder so a better reinforcement.
No calipers, but I have random bits and bobs lying around that I can just trial and error until something fits. Thanks!
This is just called plastic welding and it's fantastic
@[email protected] I would suggest carbon fiber rods or aluminum, ferris metal could interfere with the bluetooth radio depending on their shape.
Somebody suggested wooden dowels so I'll probably try that just because I have scrap wood lying about anyway and it's easy to carve into shape. Thanks!
I seriously doubt that.
I'm just a lowly embedded engineer working on BLE on aarch and other SOC kernels.
And I’m a 30 year veteran EE who designs a lot of high speed and RF gear. There is zero chance ferrous metal rods to repair the headphones as described would have any meaningful impact on the Bluetooth connection.
You’re technically correct that metal in the vicinity could possibly have some measurable impact on the 2.4GHz radio, but your theoretical scenario is a practical absurdity.
Low power BLE has been fickle to me so I guess I was being a little over cautious worrying about interference for such a small radio and low power.
yeah, everyone is an engineer on Lemmy. there is ferrous hardware all over BT headphones.
I was worried about the two rods running as dipole interference but I guess I was being over cautious
Maybe try JB-Weld? Idk if super glue will hold up here.
https://www.jbweld.co.uk/copy-of-marineweldsyr-25ml
This may be a winner, thanks!
They make a Plastic Bonder product that I've had good luck using
I used this to repair my headphones yesterday, so it will probably work as long as there's enough connecting surface area
It won't work unless there is a large surface area.
Came here to say this. JB-Weld is really great stuff. I've fixed a lot of things with it.
Jb weld was going to be my suggestion too. Good luck OP
There is a jb-weild specific for plastic that works well
https://thistothat.com/
Glue guide!
Bookmarked! Thank you
Glues are fucking useless unless you have a large surface area to bond. Headphones don't use ABS, too brittle. The use polycarbonate on the hoop that breaks and that doesn't bond well with glue.
Hot staples are an option because the embed steel wire into the plastic. These kits are cheap now and very common in automotive plastic repair because glue is universally useless.
You can also weld in metal wire with a soldering iron. I've done repairs that way before and it works quite well as long as the two pieces can't move and fatigue the metal.
If the adhesive route fails, it looks like there are replacement parts available, but your mileage may vary when it comes to the source. Not seeing anything official, but ebay has a few hits: https://www.ebay.com/itm/204942975498
Might also try just calling Sony support, but iirc their support is fairly shit.
Came to basically say the same thing. Parts also on AliExpress, looks like the same pictures from eBay so might be the same products. "Fixing" the plastic joint that has so little surface area and is mangled as much as it is seems like it would be dubious at best.
If it were me, I would be looking at buying a replacement bracket first, and if that didn't pan out, I'd probably be looking to 3d print something that would function as a new bracket or an entirely new headband.
I am but a poor student so I'll try and repair it first, but it's good to know there's parts out there if absolutely necessary - thanks!
UV Glue will fix that no problems, and the glue will be stronger than the underlying plastic.
The problem with uv glue is it needs light to cure. So it can't be used to fill that broken area or inside the break itself. It can only coat the outside.
Not with that attitude (unscrews the entire thing and shoves in a UV light on a wire in the gaps)
Next time I find myself with the right assortment of junk, it would be interesting to run a piece of optical fiber through UV glue inside an opaque enclosure and see if it helps the light get where it needs to go. There's decorative stuff that glows from the sides with a visible light source so I'd expect it to do something worthwhile in that situation. Could be a waste of materials for almost every possible use but maybe it'll solve a weird problem eventually.
I never said it would be pretty. The other option would be to get some clay and make a mold around the break and then remove it and cut away at the break and replace the mold and UV the glue until it comes out as a resin and then take a buffer wheel to the UV Glue. Personally I would put up with the surface repair myself.
I didn't even know there was such a thing. Buying a UV lamp for a single repair when other options are available feels a bit antithetical to the Solarpunk ethos though, so I think I'll try normal glues first. But hey, if all else fails, at least I know there's a nuclear option as plan b. Thanks!
There is a JB Weld UV glue product that comes with a UV LED attached:
https://www.jbweld.com/product/superweld-light-activated
It's a blend, not pure UV resin, that will harden quickly where the light hits it but will also slowly cure without UV exposure, so the inner parts of the joint will harden over time.
I use this and I've found that it is almost as good as standard 2-part epoxy in most cases, and easier to use.
You can also cure UV glue in sunlight. It's a bit of a pain and can take longer, but it's an option.
Solar
punkglue. Hmm...If you're trying to be true to the "solarpunk ethos," do you really think this is the last repair you'll ever do?
I, for one, have never regretted letting a 'one time' project be an excuse to get a new type of tool.
(Just don't get the disposable UV light another reply mentioned; that really is a bit wasteful. If you decide to go the UV glue route, get an inexpensive but proper standalone UV flashlight.)
Depends on the tool and its cost for me. If its something I can realistically see using again and is a reasonable price then sure.
The glue 'dries' clear and if you can do without your headphones for a while, the UV radiation in sunlight will do the trick, you just have to be patient. That is why most people use UV lights. Besides if you have the light, you can just put it aside until the next time you need it. I got a reeeeeal cheap one that is used for LOCA glue that they use for nail work to glue on decretive long fingernails but I used it for gluing LOCA adhesive for my cell phone screen protectors. Once you have it, take the battery out or insulate one side of it, and then you have it for the next time you need it. here is one like I used but there are a ton of cheap ones...(not an affiliate link)
https://www.aliexpress.com/item/1005008406384030.html
I have never seen this to be true.
If it’s ABS (which most thugs are) try methyl ethyl ketone to melt it back together.
Just a dab of MEK will melt the plastic, but it evaporates/dissolves quickly. Once you apply it press the pies together firmly for a few minutes, then let it cure for a while after that. The bond should be as strong as it was from the factor. Then if you want apply some JB weld for extra strength.
Let's not suggest a neurotoxin.
Gloop gets used in 3d printing. It physically welds the bonds together on a molecular level between 2 plastics.
Gloop is just acetone and tetrahydrofuran. That shit is toxic AF.
I'll be honest, you're probably not going to be able to fix those to a degree that I'd trust. Some headphones are reparable and have replaceable parts, and that isn't one of them. I've had really good luck with Audio-Technica and Beyer Dynamic in that department, but most of their more sturdy and repairable headphones aren't very portable.
I bought a cheap Temu plastic repair welder (melts in a little metall pin) - they actually work and the results are surprisingly strong.
Try layering several times with super glue and tissue paper.
Oh I've never heard of that method before! I'll keep it in my back pocket as a last resort if all else fails, thank you
I've done some awful things with various 2-part epoxies, maybe try one of those with a piece of dowel in the square holes? Not sure exactly what you have to work with there but that might give you a little extra support from inside while your glue of choice just has to keep the rod from slipping. Start with one a little larger than the holes and sand the sides flat until it fits with a little extra space, add glue, press together, let it cure.
For bonus points, you can scratch up the inside of the plastic with a rolled-up piece of coarse sandpaper or something to try and give the glue an extra foothold.
Awful things?... Dare I ask?
I'll definitely try reinforcing with a dowel or metal rod though, thanks!
Nothing that interesting, just enough to gain a reputation as somebody who can do solid in-the-field temporary fixes when a real specialist isn't available. One that comes to mind is a portable toilet that was delivered (clean and empty, thankfully) with a split in the side of the tank. Guessing they got a little too close to the trees on the way in and the driver wasn't paid enough to care. There was another one in good condition so this wasn't a critical issue but still an inconvenience.
Wasn't too bad, I could just about span the full length from pinkie to thumb tip and there wasn't any missing material. More than I'd trust glue or tape alone to hold for long though. Drilled a series of holes in parallel lines on either side of the split and stitched it shut with paracord before painting over it with a 2-part epoxy as a strong liquid barrier. Don't remember what kind it was but it remained somewhat pliable when cured so I figured it wouldn't turn brittle and crack. It held for the duration of the job and didn't leak as far as anyone could tell (and if it had, the terrain would have made that obvious).
Not the most exciting story of heroism under pressure but I went from learning about a problem to finishing the fix in about 45 minutes with fading daylight.
That looks like toast.
3D printed replacement parts might work. If you have a maker space around you, you might be able to find someone to help you with the drafting/CAD.
This is a tough one, mainly cause of the strains experienced in that position. If you're daring, maybe try some acetone to "melt" and refuse the plastic. I don't think an adhesive is going to be much help unless you cake it in epoxy, and reinforce the stress point.
Unfortunately there’s a wire running through one of the broken pieces so melting is probably a no-go because I don’t want to melt the insulation. Thank you though!
The insulation on wires is not abs.
Superglue sprinkled with baking soda creates incredibly strong bonds. But you'll need to add it all around the seam to make a thick layer.
I also recommend first scratching the plastic with sandpaper so that there's something for the glue to hold on to.
As others have said, copious amounts of super glue or epoxy. Pro tip for the super glue is to sprinkle baking soda on it to speed up the cure time.
Like the layering glue and tissue paper idea, I've never heard of this but a quick search shows you're not speaking gibberish. I'll remember that one for future repairs, thanks!
I once witnessed an old-timer in the biz repair a copier gear with the super glue and baking soda. Wasn't supposed to be permanent but he forgot and the gear out lasted the copier contract.
Just think how relatively strong even thin paper mache is. That is typically made by kids with newspaper and PVA, but its got some strength to it.
Now think of a stronger glue, its not a bad idea.
physical reinforcement is a good suggestion lots are coming up with. If it's not too late, I'd recommend doing that with something that dissolves the ABS instead of an adhesive. ABS dissolves readily with a few solvents, like acetone. Get physical reinforcement in place, and IF you do not need any bulk filler, just use a solvent like acetone to literally melt and repolymerize the plastic back together. As long as there's no new gaps or new voids, the physical reinforcement should leave it stronger than the original. At least after all the solvent evaporates away.
If you need gap filler or bulk reinforcement, two part epoxies are definitely the way to go, though make sure to use something quite flexible or it'll just crack off the next time you drop them.
Speaking of physical reinforcement, when my headphones broke in a very similar way I was able to use cable ties to secure them back together. Ugly but it worked.
The headphones I currently use (on my head right now) also have physical reinforcement, but instead of zip ties it's just a thin tensile wire I had lying around. (If you mean ye olde twist-ties like in grocery store produce sections, then that's close!) Tied it around a cylinder piece that broke off that holds a rotatable insert, superglue, and lots of extra wraps encased in superglue... and it's perfect! ... outside of where I was dumb and got glue between the rotatable faces and now it binds up a bit, but otherwise great. Replacement parts would've been like $35+.
... I guess all of that is to say, physical reinforcement is excellent when it's adding strength as opposed to replacing strength! (similar to OP, the superglue is a bit brittle for a one to one toughness fix).
A few people have recommended acetone now. I originally ruled it out due to the wire running through one of the hollows (not wanting to damage the insulation) but I'm thinking I might try adhesive on the piece with the wire and acetone on the other. Thanks!
Not sure i would use a plastic stapler/welder for something like this with small electronics but it is for plastic ... If you're careful it might work long term. Just be clean and accurate and don't leave pointy bits that could cut you. The staples need to be trimmed after and it would be best to melt more plastic over it probably.
Unfortunately there's a wire running through one of the broken pieces so heat is probably a no-go because I don't want to melt the insulation. Thank you though!
I think a deft hand could do what OP suggests without damaging the speaker wire. This would be the metal reinforcement you need combined with epoxy. Just sink the staple in far enough to work. Maybe two per side. Not too deeply as to roast the wire.
Edit: Though if you do not own one, then that solution is out.
I don't own one and I'm terrible at the game Operation. In more skilled hands perhaps it's possible but I think I would just mess it up - thanks though!
No worries. I don't own one either, but I've thought that I could heat a flat, but wrinkled paperclip with a heatgun and it should do the same thing. Barring that, I would then do the internal metal reinforcement others have suggested and the string/glue wrap. Post your results!
Loc-Tite Plastic Bonder has worked well for me in these situations, but sometimes it just doesn’t seem to take well; other times it holds better than the original plastic does. Worth a shot?
This looks like Loc-Tite's version of the JB Weld Plasticweld. If I can't find any JB then I'll give this a go, thanks!
Ouch, I used hot glue for mine but its not great at holding to the surface, I just had a massive surface to make use of and pretty much made a ring of glue around the break. Doesn't look like yours would work with that sadly.
So, probably don't go with hot glue.
Noted, thanks though!
Acetone can join ABS because it is a solevent for that particular plastic and will mix the two treated surfaces at the molecular level. It would be wise to add some additional material in the hollow area such as an epoxy putty (jb weld as suggested elsewhere), but it should create a stronger bond between the broken pieces.
There's a wire running through one of the plastic pieces so I think acetone is probably a no-go because of the insulation. I'll keep that tip in mind for future repairs though that don't have that difficulty, thanks!
5 minute 2-part epoxy. Buy the individual packets rather than the bottles so ya dont get solidified wasted bottles.
If you're up to a bit more complex of a job, I have files for headphone bands to replace the whole hinge and band with either 3D printed or cut metal.
3d printed can be done with any printer either as is or flat and then shaped with an oven to specific designs.
Metal needs only a dremel, drill, and sandpaper and can be made out if sheet steel from any hardware store. Bending is done by hand or 3d printed jig.
Both use 3m screws to be adjustable but can be glued in place if prefered.
That sounds a bit outside of my skill range - thank you though!
You can glue it, it won't work. When you've tried all of them, get a plastic staple gun and make it ugly, but fixed.
General purpose tip for Gluing:
Isopropyl Alchohol in a spray mister will speed up Superglue bond time from minutes to seconds.
Mixing glues can be very useful. For example, I'll use Epoxy for the hollow insides but a drop of Superglue where pieces fit together to hold the pieces together while the Epoxy cures overnight. UV glue is fantastic for that because it cures instantly. But a drop of Superglue with a spritz of alcohol works good too.
Cyanoacrylate accelerator is not IPA. It's a mix of acetone and amines. You are getting a weak effect from the water in the IPA.
I didn't say it was accelerator but it works like accelerator. This is the solarpunk forum where you are supposed to recommend hacks.
I didn't think of mixing glues, nor have I heard of the alcohol spritzer thing - I might give it a go. Thanks!
Whatever you do, don't break that wire, it's nearly impossible to DIY repair.
I think you're cooked with adhesives and are going to have to modify them for a proper repair. If you keep at adhesives, make sure you're curing properly with temp, weight, time.