Hello,
I have a 1983 240d,
I have a friend who offered to paint my roof this weekend, and I've been wanting to repaint my roof a different color for a while. I'm going to buy the paint, and I need to know what type of paint to buy in order for the finish to turn out right/not crinkle or crack. Any help would be greatly appreciated.
Thanks, Alex

In some parts of the world you can only buy water based automotive paints - but in others you can get the more traditional oil based "original". Where ever you are you can only get what's available. Perhaps the best way of asking the question would be so say "does anyone know if this brand XXXXXXXXXX of automotive paint is any good"?

In any case - no matter the brand - the secret to a long lasting paint job is in the preparation. This is tedious and takes a long long time to do well. There are loads of how to sites on the internet for this - do you want a link or can you save yourself?

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I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

Most modern cars are available with pearlescent or metallic paint, although metallic paint has been used on cars including Wolsleys since the 1960s, and pearlescent is a development of the American custom hot rod scene of the 1970s. Both these paint types rely on flakes of material added to colored paint, which is then coated with several layers of clear paint which are buffed to give the final finish. If the flakes were exposed to the elements or buffed, they would degrade or oxidize, ruining the finish. Therefore the “clear over base” method is used.
Metallic paint consists of tiny aluminum flakes, purchased separately from the paint and mixed into it to give the required metallic effect. The effect is controlled by the proportion of flakes used, their size distribution and their reflectiveness, and dozens of types are available.

sand the original paint with 320 grit paper, put a sealer coat on ( reduced primer ) then the color. The sealer coat isolates the old form the new and should be done regardless of what the original paint is, thus preventing any reaction in the event you have laquer on the car ( highly UN-likely as most early 80's cars would have been base clear if metallic, or a urethane single stage if a solid color )

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'83 240d's have no lacquer unless they were refinished with lacquer. The only lacquer cars left by then were the small British makes (Rolls, Morgan, etc.). You really won't need the primer unless the roof's coating is damaged.

Also the crinkle and crack is usually when too much paint is put on. Also the more layers, the less sure the adhesion. Most apply a base/clear over the previous finish w/o primer. Primer is only necessary over repairs and bare metal situations. Good shops etch the existing coating before refinishing to promote adhesion. Ask for suggestions where you buy your paint.

340 grit is pretty aggressive for a car. You can see a lot of what is called "sand scratch" when you stop at that grit. Etching will avoid sand scratch.

As "Stretch" says, the prep is the killer. More prep, better appearance and durability. Also, most companies have a good product. What you have to watch is the low cost lines within a brand. Generally, only the most skilled can get decent results with the cheaper lines.

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