Mending plastic

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JHZR2

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Stupid me, used the wrong tool for the job. Trid to load an oversized parcel into my car. Long story short it fit in the backseat, I dropped it in with the convertible top down and tried to close the top. I went slowly but there was a misalignment and popped one plastic fastener.

7C48C202-85F6-4279-87F4-905A25A72EEA_zpsxfectl2h.jpg


All but one fastener were able to pop out of their holes; the one that busted was screwed in. Of course that means that the plastic backing that makes the parcel shelf came apart. I'm assuming that this screw piece is molded into that plastic backing of the parcel shelf. Not currently sure what that plastic material is. What would be common? ABS? PE? PVC?

I'll try to find a marking and report back exactly what it is later. Top closed A-OK and everything seems fine but Ill open it later to investigate further plus find the material. Let's just assume that it is ABS. If it is what I used epoxy or would I use ABS pipe cement? If it is some other type of plastic what would I want to use then?? Should I plan on using epoxy regardless? What would be inappropriate automotive grade to use? What sort of your time is one better or stronger or longer-lasting then another?

TIA
 
Originally Posted By: Donald
Pull up the conv. top, by hand if needed. Duct tape it in place.


Read my post??

Top closes just fine. Just busted one fastener on the movable parcel shelf because it was screwed down, not fixed by a removable fastener. So the plastic which I assume was molded to hold the threaded rod/bolt yielded and broke.

Happened so fast that all I heard was a pop.

Everything else is perfectly fine it seems I just need to repair that piece of plastic with the appropriate adhesive. Worst-case just buy a new plastic shelf, but since nothing is busted I may as well attempt a repair first using the correct stuff.
 
Originally Posted By: JHZR2
Originally Posted By: Donald
Pull up the conv. top, by hand if needed. Duct tape it in place.


Read my post??

Top closes just fine. Just busted one fastener on the movable parcel shelf because it was screwed down, not fixed by a removable fastener. So the plastic which I assume was molded to hold the threaded rod/bolt yielded and broke.

Happened so fast that all I heard was a pop.

Everything else is perfectly fine it seems I just need to repair that piece of plastic with the appropriate adhesive. Worst-case just buy a new plastic shelf, but since nothing is busted I may as well attempt a repair first using the correct stuff.


My post was an attempt at duct tape humor.
 
How much gap is there between the trim piece and the underlying panel?

If enough, you don't necessarily need to use the original fastenting point, and perhaps some double-sided trim/body tape or even a velcro strip will suffice. If you need this broken post for panel alignment, then that method may not work quite as well.

Otherwise, I'd remove the entire panel and use an epoxy based mend. Again, I'd do that off the vehicle, so as not to create a mess. It's going to be a harder fix as it is going to deal with the rotational torque of the screw. On some vehicles, you can also try to heat fuse the broken piece, and that is in fact how some door panels are assembled at the factory. But you don't have much on the other side to work with.

I'd opt for the double sided tape fix, unless you need real strength or further regular access underneath it.

You're more easy about it than I am. I am a stickler for trim attachment, hate trim mis-alignments and rattles, and hate even when someone mixes up the fasteners in reassembly. If it's a nice vehicle, I'd probably be on e-bay hunting down a new trim panel. So my hat is off to you.
 
Originally Posted By: sleddriver
Good luck finding something that adheres well to PE or PP...tough to glue to.

Urethane, like NP1?
Vinyl cement?
ABS cement?
Hot glue?


Dunno, that's why Im asking
smile.gif
 
Originally Posted By: Volvohead
How much gap is there between the trim piece and the underlying panel?

If enough, you don't necessarily need to use the original fastenting point, and perhaps some double-sided trim/body tape or even a velcro strip will suffice. If you need this broken post for panel alignment, then that method may not work quite as well.

Otherwise, I'd remove the entire panel and use an epoxy based mend. Again, I'd do that off the vehicle, so as not to create a mess. It's going to be a harder fix as it is going to deal with the rotational torque of the screw. On some vehicles, you can also try to heat fuse the broken piece, and that is in fact how some door panels are assembled at the factory. But you don't have much on the other side to work with.

I'd opt for the double sided tape fix, unless you need real strength or further regular access underneath it.

You're more easy about it than I am. I am a stickler for trim attachment, hate trim mis-alignments and rattles, and hate even when someone mixes up the fasteners in reassembly. If it's a nice vehicle, I'd probably be on e-bay hunting down a new trim panel. So my hat is off to you.


LOL, Im not easy about it... Its a like new BMW, and I like to keep my cars as-new...

but it was my fault and Im trying to stay positive...

There are a bunch of pop-in fasteners, and the back edge of it fits under a screwed-on piece of metal trim, so I imagine it is on there pretty tight regardless of this. That said, while there are lots of fasteners in general all over, this is the only one in its area...

Im not opposed to buying a new panel to keep it as-new. That said, I feel obligated to try a repair, as the process is the same in the end if I hae to replace the whole thing... Might as well give it a try.

Just need to find the right product to give it a try. If a failure, buying a replacement is straight forward... If epoxy is smart, even for ABS or PE or PP, etc., then so be it. If it really is material dependent, then so be it as well. Just researching so I can get it attempted to fix ASAP.

Thanks!
 
If it's that tight, I'd see if a strip of double-sided trim tape holds it down. Ask a local body shop if they'll give you a length.

If not, on a really nice car that new, see if you can get a fair deal and just replace it.

Chalk it up to a lesson learned and move on. It happens. That's why they have parts counters.
 
Can you seperate the black plastic from the grey plastic? If so, maybe just put low profile head bolt with a big washer in from the top and use a nut where the current screw head is?

There are guys that specialize in welding plastic too, I've thought of having some of my automotive plasitcs mistakes fixed, but then I get the part from the wrecker for near nothing, so I've never given one a call.
 
Originally Posted By: IndyIan
Can you seperate the black plastic from the grey plastic? If so, maybe just put low profile head bolt with a big washer in from the top and use a nut where the current screw head is?

There are guys that specialize in welding plastic too, I've thought of having some of my automotive plasitcs mistakes fixed, but then I get the part from the wrecker for near nothing, so I've never given one a call.


Dont think I want to go there. the soft vinyl on top is likely adhesive'd on, and I doubt that any repair to that would last (IME).
 
Originally Posted By: JHZR2
Originally Posted By: IndyIan
Can you seperate the black plastic from the grey plastic? If so, maybe just put low profile head bolt with a big washer in from the top and use a nut where the current screw head is?

There are guys that specialize in welding plastic too, I've thought of having some of my automotive plasitcs mistakes fixed, but then I get the part from the wrecker for near nothing, so I've never given one a call.


Dont think I want to go there. the soft vinyl on top is likely adhesive'd on, and I doubt that any repair to that would last (IME).

Maybe you could keyhole the black plastic from the bottom? Probably hard to do without cutting through the vinyl too.
Or maybe something like this?
f5_flush.jpg

Right through everything, exposed hardware can be sort of nice if done well?
 
Those are pretty neat but Im focusing in on the two-part chemicals now I think...
 
Loctite 414 is a super glue designed for plastics and vinyls. Might be tricky if the material is PP but I'd think it would work for nylons and PC/ABS. I've used it with good success on a handful of plastics before.
 
Keep your time in mind with this as well.

If it's a $200 part and you are spending five hours futzing with a repair, maybe your time is worth the new part.

The only instance where I will invest serious time on a trim part is if it's made from "unobtanium" or is spectacularly expensive (like the $2,500 carbon fiber console trim on my R129).

Otherwise, it's the parts counter or the bone yard.
 
Originally Posted By: Volvohead
Keep your time in mind with this as well.

If it's a $200 part and you are spending five hours futzing with a repair, maybe your time is worth the new part.

The only instance where I will invest serious time on a trim part is if it's made from "unobtanium" or is spectacularly expensive (like the $2,500 carbon fiber console trim on my R129).

Otherwise, it's the parts counter or the bone yard.


Yep. Well the time saver would be not unscrewing all of the trim that holds the one edge in... As well as the time to go to the dealer to get the part, etc.

I will if I have to, but IMO this is straight forward enough if it works that its worth the gamble. Point well taken though!
 
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