Strongest way to bond two plastic surfaces?

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Caporegime
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Warwickshire
Hi all

One of the lugs on my car's luggage cover broke (see pic below).

Unfortunately this plastic lug is not individually serviceable and the dealer has advised that the whole load cover unit would have to be replaced at the cost of about £700.

I have an extended warranty but this part is apparently not covered. I'm drafting a whinge but assuming this is unsuccessful, what's the strongest way to bond these two items together please?

I'm familiar with epoxy but 1. will it hold and 2. is there anything better? Is there anything like plumber's solvent plastic weld for example that could work?

This is a fairly high-stress piece of plastic so I'm assuming whatever I try will eventually break again.

Cheers.

Edit: for clarity hopefully - the plastic lug is the guide runner than slides along rails (one on each side) to extend and retract the cover when the boot is closed / opened.

tcq0YLfh.jpg
 
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Although I have some bondloc plastic weld in the fridge that I've used on plastic parts,
for anything load bearing I've braced similar breaks with another piece of plastic glued or bolted in parallel - Kintsugi.
 
Something like fiberglass body filler, should (a) stick it due to the solvent, and (b) would be able to be worked into the waffle like plastic saving design that's failed so completely, to provide extra rigidity.
 
Another vote for epoxy resin.
The honeycomb section will also give the resin something to hold on to for strength, if you fill and paste over it as you bond them together.
 
I've fixed motorcycle fairings and other plastic items around the house.
I've used plastiweld which is a powder and liquid which when mixed together welds plastic back together it's also great for building lugs and rethreading holes.
I've also used a plastic welder which is really just an adjustable heat gun with changeable nozzles to fix cracks.
The important things to remember are don't overheat and burn the plastic and make sure you use the same plastic to repair as the base material otherwise it won't hold.
 
Thanks all. Consensus seems to be that epoxy is the best thing, so I'll give that a go first as relatively cheap and simple.

I've ordered this as it seems to be specifically for plastic and dries black:

4rRW9Skl.jpg
 
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I don't think you'll get a high enough strength joint just using glue, there is not enough surface area in the break for that. If you want a strong fix I would drill a matching hole through the centre of the break into each piece of plastic. Then glue a metal pin into one of the holes that is long enough to fit into the hole on the other side. Then glue the two halves together with epoxy. The pin effectively becomes an internal splint spreading the load through a larger volume.
 
One I have used previously was to search out if the broken part is, was a well known issue and in my case, I presented Specialized (who denied there was an issue) with links to UK, Europe and America websites, highlighting the issue and had all the work done for free.

Might be worth an hours search.
 
jonchaz said:
I don't think you'll get a high enough strength joint just using glue, there is not enough surface area in the break for that. If you want a strong fix I would drill a matching hole through the centre of the break into each piece of plastic. Then glue a metal pin into one of the holes that is long enough to fit into the hole on the other side. Then glue the two halves together with epoxy. The pin effectively becomes an internal splint spreading the load through a larger volume.
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This is a great shout, like a tiny piece of concrete rebar. I think once I've done this it'll be stronger than the other side!

aVdub said:
One I have used previously was to search out if the broken part is, was a well known issue and in my case, I presented Specialized (who denied there was an issue) with links to UK, Europe and America websites, highlighting the issue and had all the work done for free.

Might be worth an hours search.
Click to expand...

Thanks for this; I already had a Google last night and it seems quite a niche situation for this car, so there's not a load of disgruntled owners sharing the same problem unfortunately. I did find a few similar forum posts on it but with no resolution.

robj20 said:
I'd cut some of the honey comb section away from each side as well and fill it with the epoxy it'll be stronger than before that way.
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Interesting take; I was thinking (and agreeing with some of the above posts) that the honey comb would both add structural strength and provide grip for the adhesive. I think I'll leave it for the moment but will bear in mind.
 
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godinman said:
If that's the same glue I used it has 'Warning, Cancer' written in the back, which is somewhat alarming, make sure to wear gloves!
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Epoxy is a relatively safe resin, polyester resin (most car body fillers are polyester based) would require a bit more care in larger volumes as it gives off styrene when curing unless specifically styrene free (wear a mask for this, especially if you have asthma).

[Edit] That said, I have used some 'Bloc' branded epoxy that I ordered off Amazon, it wasn't typical epoxy and gave off horrendous fumes. No nonsense brand from Screwfix is quite good.
 
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Thanks all. So the plan is:

- Sand both surfaces to key
- Clean with isopropyl
- Drill four small holes (two each side) and insert four pieces of metal sewing needle (cut with tin snips)
- Bond with the above epoxy adhesive, clamp, and leave for 24 hours
- Spend the saved £690 on whatever I want (man maths / justification)
 
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