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.
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.
- fix the pieces in their intended position (maybe with a droplet of epoxy)
- bring out a dedicated soldering tip (you won’t be soldering with it any more) and 3D printer filament of the same plastic
- weld carefully with a low-temperature iron, in a well ventilated place (maybe outdoors)
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!
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 bought a cheap Temu plastic repair welder (melts in a little metall pin) - they actually work and the results are surprisingly strong.
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.
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. 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!
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!
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!
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!
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!
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.
@punksnotdead@slrpnk.net 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
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
Glue guide!
Bookmarked! Thank you
Maybe try JB-Weld? Idk if super glue will hold up here.
Great for:
- PVC
- ABS
- Rigid plastics
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
