From: Mark Norman
Date: Tue, 9 Mar 1999 15:33:54 -0000
Subject: [imps] plastic deterioration/rear window stays revisited

I now have the rear window stays that Tim was selling, and although the plastic is good it shows some signs of 'bio-degrading' on the surface. (No complaint there Tim - I'm very happy with them). Presumably this is due to sunlight. Has anyone tried painting them to protect them? Did it work, etc etc.

In general does anyone know how to beat this kind of deterioration - the only other things that I can think of on the Chamois that are affected like this are: Although I can't see any way around replacing these once they are gone, can anyone suggest ways of preserving them? (Other than by keeping the car in the garage & not driving it!)

If no-one has tried painting the plastic before, then I'll give it a go & let you know what happens.

Date: Tue, 9 Mar 1999 07:50:43 -0800 (PST)
From: David Edge
Subject: [imps] Re: plastic deterioration/rear window stays revisited

I wouldn't do it, paints can have some pretty catastrophic results on plastic depending upon the solvent and plastic. Maybe if you go for a modern acrylic paint if won't harm. Motor shops do sell paints especially for refinishing vinyls etc.

From: Impmann@aol.com
Date: Tue, 9 Mar 1999 11:39:21 EST
Subject: [imps] Re: plastic deterioration/rear window stays revisited

The varnish on the Chamois is a funny one. I pulled a Chamois out of a shed that had not seen daylight for 22 years and the varnish had all cracked up.
The interior of the car was a dry as a bone too (I looked at it in mid-winter too). I think that the cracking is just down to age and perhaps some kind of chemical instability in the varnish.

The crash roll pads (top of the dash) on later cars are badly affected by sunlight problems, but I have found that the earlier cars aren't so suceptable (perhaps I've been lucky). In fact Mark, I've got a perfect passenger side (long one) crash roll pad for a Mk2 Chamois in the garage if you're interested... (cheap).

I haven't had many problems with the vinyl cracking on Imp backseats, its mainly the sitching that goes or wallies with cigarettes or sharp objects. The worst car I ever had for sunlight corroded back seat was my Mk2 Granada... then again it was one of the worst cars I ever owned...

The other item to go brittle with age is the headlinings... especially in coupes. The original type headlining is officially unobtainable too... bummer.

I too would err on the painting idea. The plastics are already getting delicate, and the action of the solvent evaporating from the paint may actually speed the process. What about silicone sprays? Would they work?

From: Mark Norman
Date: Tue, 9 Mar 1999 17:40:24 -0000
Subject: [imps] Re: plastic deterioration/rear window stays revisited

I don't need any crash roll pads thanks, I covered my ones in new vinyl after filling the cracks - they look very good, but you lose the indented pattern.

My old rear seats cracked all along the top - the material used there seems a lot thinner than the seat faces - I managed to superglue backing material to this to patch it for a while. This worked quite well & looked better that you would expect, however the material had got weak all over & would give way somewhere else soon after I fixed each tear.

Well, 2 votes against painting the plastic, none for it - its not a popular idea so far!

From: Gary Henderson
Date: Wed, 10 Mar 1999 10:17:14 +1300
Subject: [imps] Re: plastic deterioration/rear window stays revisited

Try coming to the Ocean Hemisphere, where we get REAL sunlight... official sunburn time here is about 12 minutes on a reasonable day. (Less at high altitude.)

The plastic parts of the stays were painted originally, but the Dulon didn't really stick to Delrin (?) so they're mostly au naturel by now. The level of solvent attack required to make the paint stay put would probably do just as much damage. Mouldings with lots of carbon-black last longer in the sun.

UV destroys vinyl (especially if helped along by alkaline cleaners), paint, rubber, ABS, nylon webbing, fabrics... Metals don't mind! My window-rubbers now have advanced surface failure - I'm amazed it doesn't leak yet.

Best try to park under cover whenever possible.