Best glue for fixing plastic together

[David Hearn]

I have to re-attach a piece of plastic which is the pivot for 2 pieces of plastic to hinge. It's like a plastic rivet. Unfortunately the top of the 'rivet' has come off (top is about 2cm across) and needs to be glued back onto the shaft (about 1cm diameter tube, about 2-3mm of material).

What would be the best glue to do this, considering that it is under quite a bit of stress when the 2 arms are flexed?

Whether or not it is a long term fix is another matter - I just need it to work for as long as possible.

Thanks

David

[Ian Stirling]

What sort of plastic? Gluing plastics is problematic in general, many simply don't glue well. Chances of repairing a structural element is fairly small. Does the bit of plastic have any recycling marks? (3 arrows, with a number inside)

[Dark Angel]

Try 2-part epoxy, like Araldite. That'll stick most things togethor, and is fairly durable.

[ben]

Araldite

Without seein/knowing the what it really looks like I doubt whether you will a succesfull fix if the area is taking stress on it with glue, could you not make another rivet? Modellers shops sell all sorts of plastic rods/sheetplastics.

[Mike Dodd]

I'm having difficulty visualising this, but as well as glueing, would it be possible to drill a fine hole through the "rivet" and insert a steel pin (even an expendable drill bit?) to give it some additional strength?

[Grunff]

Think about this - your rivet has already failed once, and that was from an un-glued starting point. You have zero chance of getting this to work.

Other options to consider:

- Steel machine screw through the rivet

- Replace rivet with a new one

- Replace rivet with steel equivalent

[ben]

Mike Dodd wrote: [snip]

Yes it would have been better if the OP pointed out what it is he's trying to repair.

sounds like a hinge on a everyday item of use? mobile phone/Laptop?

[Lobster]

Sounds a tall order for any type of glue... also, the optimum glue would depend on the type of plastic - what is it?

I'd definitely go for some form of mechanical reinforcement here - can you replace the shaft with a metal component, eg a bolt with a locking nut at the other end? (Is the cosmetic appearance important - you don't say what the application is) Or at the very least, if you do repair using glue, you could drill a small pilot hole down the centre of the top and shaft, and fit a screw to pull the whole lot together and reinforce it.

David

[Dave Plowman (News)]

It depends on the plastic. But unless it's one where there is a true solvent like say perspex,it's unlikely you'll get a strong as new repair.

[Rob Morley]

Without knowing what sort of plastic, and in what sort of application, it's not easy to guess. How about splurging a load of hot melt glue down the hollow bit then whacking the end back on?

[Andrew Gabriel]

I had a plastic lug snap off one of the internal shelf doors in the freezer. This looked like it might be a problem to glue, so I melted the two surfaces quickly over a gas flame and pushed them together, and it's been fine for the 10 years of use since. Obviously, this only works with thermosoftening plastics.

[David Hearn]

Thanks for all the advice. In the end I decided against gluing because of the weak bond it would probably end up with. The item is basically something 2 foot long with a large 'hinge' in the middle (completely plastic item) to fold it to half size - visualise one of those old rules which folded in half.

The two halves were fixed together by two plastic plugs with a screw which held them together. I cannot see exactly though how they screwed together as removing the screw does not allow the two parts to come apart - maybe someone's repaired it before??

Anyway - my fix in the end was to replace the plastic collar bit which came off, with a large metal washer. A screw used to go through the middle of this collar, so I could just screw the washer on with that. I had hoped to also replace the screw with a longer one, buy B&Q didn't have any suitable.

This is something I've sold on eBay for a not insignificant amount (not enough to just refund the money). It literally fell apart as I packaged it! (It's ex-work). The fix makes the item completely working again and likely to be much longer lasting than either a glued repair, or even maybe the original design. Therefore I'm completely happy to pass the item onto the purchaser - in fact, I'm glad it broke before it got posted, and otherwise it could very well have broken either in the post, or more likely when the purchaser first had a fiddle with it.

Thanks again

D

[Harry Bloomfield]

Glueing plastics never works well. I'm struggling to understand the description of part your are trying to glue anyway.

I find I have some success by hot riviting small broken plastic parts. For smaller parts I use ordinary paper staples, bent so provide the reinforcement needed, then pushed into the plastic with an hot soldering iron.

[John Schmitt]

There is quite a range of plastics. If you can shave a sliver off, hold it in tweezeers, light it note the nature of the flame (if any) and the odour on the flame going out, I could venture a guess.

John Schmitt