Repainting Door Panels

[chrissonger]

I need to repaint my door panels on my 74 Rallye. They were originally green before being painted black 20 years ago. It wasn't a bad job originally, I made the mistake of scrubbing it before realizing it had been painted. I'm planning to use all the SEM products. I've watched a few videos and feel fairly confident. My concern is, how much should I be concerned about the previous paint? Wondering if the soap and Scotchbright is enough. Or should I strip that previous layer? If so what? Thanks!

[DAYLEY/CHALLENGER]

Scrubbing with anything will probably remove some of the texture.  Hard to say which is the best way to go. 20 years ago....what type of paint was used?

[jimynick]

If some of it is coming off, then it's likely, though not positively, that the rest is just waiting for an opportune moment. Know what I mean Vern? You could try a car wash sprayer, but I'd test it on a kick panel first to see if it messes up the texture. Careful application of a fine 3M sanding pad using some Simple Green, a good rinsing with hot water, blow it dry and a quick, and I mean quick, wipe on with one hand and wipe off with the other with MEK and then usually about 2-3 coats of the Sem and you should be good. Other than dealing with prior paint, that's the way I did my 74 Rallye. Good luck! 

[chrissonger]

Thanks, I have one of those McCullough wand type steam cleaner that I thought might help. The panels seem kinda chalky as well.   

[318Stroker]

You can use lacquer thinner to remove paint on E-body door panels. I've done it with no adverse effects. Put it on a rag and wipe. I suspect if you left it on too long or soaked them in it you would damage them.

[chrissonger]

I was thinking the same thing. Probably don't need to remove 100% of the previous coats if it's still adhering. I'm thinking a little sanding might be needed where it's chalky but I'm concerned about messing up the grain...

[PLUM72]

I like the pressure washer (car wash) idea.  Might also try soda blasting the part.  Soda blasting is supposed to be plastic safe.

[7E-Bodies]

IMHO do NOT hit those chalky areas with even a 1700# pressure washer (the cheap ones). I'd fear that it'd cut right in. The kicker panels don't get as much sun, so I'm not thinking that'd be a good test. BEEEEEEEEE careful.

[cuda hunter]

If they are chalky, no sanding, no power washing and really no hard scrubbing of any kind. Your better to just lacquer thinner and a soft rag.  Even then you have to really be careful not to rub off the chalky texture.

[anlauto]

If they are chalky, no sanding, no power washing and really no hard scrubbing of any kind. Your better to just lacquer thinner and a soft rag.  Even then you have to really be careful not to rub off the chalky texture.

1000%

[captcolour]

Chalking is likely just from the paint and not the plastic itself.  Do we know what type of plastic?  The most widely used now is polypropylene which has decent chemical resistance which makes it hard to paint.  Chrysler did use a lot of ABS back in the day before using polypropylene.  ABS is easy to paint (think plastic models) but has poorer chemical resistance which makes it easier to get paint adhesion.  ABS would be a harder surface and stiffer.  PP would be more flexible and a softer surface.  If PP, the old paint adhesion won't be very good so I'd use the lacquer thinner and should come off without hurting the PP including the texture.

[anlauto]

I would use "chalky" to describe deteriorating plastic, and "flaky" to describe paint in my opinion

[chrissonger]

It's chalky, as I get more into this project I'll show some pics. It's more than just the paint. Right where s sweaty arm would rest.