Broken plastic lugs

"Solvent weld" adhesive.

random supplier:

Let dry for ~24 h.

Thomas Prufer

You need to be sure what type of plastic it is. I don't think 'standard' hard plastic glues will stick polycarbonate, it specifically needs methyl metacrylate to glue it well. The standard 'hard plastic' glues will weld PVC, ABS, polystyrene, etc.

So, is it *really* polycarbonate? I'd expect interior trim in a car to be ABS or, maybe, polypropylene.

Polypropylene and polythene are very difficult to glue.

There is a stamp on the part: PC+ASA which according to

I was just about to try some Araldite Metal and a couple of paper clips. Two of the lugs have disappeared, one has the "lug" part broken but I have that bit.

The part is almost identical to

The part pushes and snaps into the courtesy light module, or I need some other neat way of holding it in place.

When I took it off (trying to sort out the alarm problem as posted separately) it is clear that someone had used some tape to try and hold bits. We've had the car from new and had no issue with the unit so guessing some ham fisted mechanic must have knocked it off, just can't imagine why.

If the plastic is meltable at soldering iron temperatures, I've used hotmelt glue string reinforced with small bits of expanded Al mesh. Hotmelt glue string, = run out some glue from a height, over some clean metal sheet and then use like a solder operation, using an old soldering iron/tip

I discovered recently that hot glue completely gives up in the presence of isopropyl alcohol. (isopropanol). Unfortunately its pretty useless at car interior temperatures which can get over 50°C.

This is a classic case where popping down a local scapyard could net you a perfect piece for peanuts

But you'll probably snap the lugs off getting it out ...

Well these days joe public isn't allowed anywhere near the cars. A person experienced in pulling cars apart will do that for you...

Complete units are available on Ebay and the state of the lugs on them are my concern. I've not seen just the casing available.

I've just tried some double sided tape - doesn't (surprise surprise) work. Tempting just to glue the cover back into place, a 2009 vehicle and at worse it will have to broken off in the unlikely event access was needed.

Yeah. I had a corroded PCB connector on the courtesy light on a Freelander. The plug was completely unobtainable and the harness would have cost more than the car to replace. So I just removed the connector and soldered wires direct to the courtesy light PCB and put it back in place.

If that car is still on the road, its still got my fix. I mean why put a connector there in the first place? Because it makes assembly cheaper and faster.

Addendum. the dear old bus' last MOT was 2021. I guess she is dead or parted out.

Grrr, the plastic is really brittle. Just tried to push it back into place with some double sided tape and I've cracked it some more despite attempting to be careful.

Presumably age (the plastic not me).

I've never had much luck gluing plastic, given that it breaks at the most stressed point. I try to put in some kind of metal reinforcement e.g. a segment of panel pin as a dowel. The flip-up cover for jars in my fridge contains most of an ISA serial port panel. Never throw anything away...

There are also plastic welder tools that embed staples in the thing to be welded. Big Clive on Temu's finest:

Theo

How beautiful does it have to be? could 3D print it...

Better than the sticky tape I've just plastered over it after last night's attempt failed.

I'll send you a photo.

Or I'll pay £15 on ebay.

I had a similar problem after removing a door inner panel on my Seat car. It was obviously designed never to be removed, judging by the fierce plastic hooks keeping it snapped in place. One of them broke off, so I put a big blob of 'JB Weld' (2-part epoxy like Araldite) around the stub and nestled the hook back. The glue dried pretty hard and let me snap the panel back into place. When in place I don't think there would long-term stress on it after the hook has engaged. Dave W

It doesn't answer this question, but I was interested to learn that some car headlights are designed for fitting a repair kit. If you break the lugs, you snap off the remnants and can then screw on a replacement lug kit:

I suppose something like that could exist for interior lights, but probably doesn't.

Theo

My ex kicked in a plastic grid underfloor vent under the Aga cooker. They were installed before the cooker/ Mice were using them as a portal.

I 3D printed a replacement and hot glued it in place.