Paint for alarm bell case?

[terrypingm]

At great risk to life and limb, six months ago I removed our burglar alarm case cover from its high position under the eaves. Its white paint was peel ing off the red plastic so I sanded it down as well as I could and gave it two coats of an all purpose primer. I thought that would be OK for another

3 or 4 years. But I was clearly wrong because it's already starting to flak e off again.

This time I'm getting my window cleaner to do it. But that means it needs t o remain in place, as removal involves some tricky wire-cutting etc. I'm th erefore seeking advice on what sort of paint I should buy for him please? I deally, after the minimum of sanding (not a nice job at that height) I'd li ke him to be able to apply it directly over the present mix of primary and the small areas of bare plastic. And not need more than one coat (unless it 's terrifically fast drying).

Any advice would be much appreciated please.

Terry, East Grinstead, UK

[Andrew Gabriel]

If it's made of PVC, you want solvent-based gloss paint, top coat only. Probably true for ABS plastic too. The solvent dissolves slightly into the PVC surface, so there's no way the paint will ever come off. Don't apply any primer or undercoat.

I haven't tried this with the current low volatiles paint, but that may be your only option unless you have some old gloss topcoat around.

If it's polypropylene, that's going to be harder. You would need a xylene or toluene based paint to dissolve into the surface, and I think those are all banned in the EU now. Maybe some model paints are still based on these in small quantities. Otherwise, it will be a case of getting some paint to stick to a roughened surface, but without a chemical bond, it will probably eventually peel off.

If you want plain white, what about getting a new external sounder?

[John Williamson]

Ideally, you need to know what type of plastic it is. Some of the softer ones are almost instantly paint repellent, and others need specialist primers.

[alan]

car spray paint

[terrypingm]

Thanks for the fast replies.

I've no idea what type of plastic this 18 year old case is made of.

Meanwhile I've bought a 400 ml spray can of

RUST-OLEUM Universal Advanced Formula All-Surface Paint

which is 'Designed for Metal, Masonry, Plastic, Wood'. And claims 'Any angl e spray, fast drying'. It cost me £13.99 from Homebase. Manufactured by T or Coatings Ltd.

A new case would have been the best option but would have meant drilling ne w holes. I recall that was difficult when I installed the original 18 years ago, so couldn't face it again now. If I'd known I'd be re-painting so soo n though, I'd probably have gone for that.

[Brian Gaff]

One of the issues with plastic, I have found is that it leaches its plasticizer over time. Thus anything one paints on it tends to not stay there very long. It makes me wonder if the plastic on your box is like this and hence the paint comes off. Brian