Older cars that use Plastic and Painted Stainless Steel trim parts often have problems of surface cracking and fading. To restore the finish of these products once they are past the point of armor-all you can use special paint that will adhere and bring new life to your old fading parts.
It is important to note we are talking about parts that are in good condition but may have weathered due to road salt or uv rays. Some Manufacturers continue to make these parts or they will often allow third parties to develop duplicates. But some cars never will get this treatment making them impracticable to rebuild and maintain.
Stainless Steel Trim
is found around windows in moldings and may be found in wheel wells or inside your vehicle. Sometimes the part is placed in a heat shrink plastic that gives the part a matching or black color. When you find a part like this is past its age you have a choice buy a new part or refinish the part you have. Stainless Steel like aluminum doesn’t particularly like normal enamel paints so companies like SEM have developed a line of paints that can adhere to stainless and restore the part. Now this won’t be perfect but the difference in replacing 20 pieces of stainless trim at $50 to $100 a piece may be the difference between other options in your project like an engine upgrade or new upholstery.
To paint the part if it needs to have its plastic coating removed you need to remove it from the car. Use a combination of utility knives and putty knives to remove the plastic shrink wrap and a heat gun or leaving the part in the sun may help.
Once you have cleaned the part you want to sand it with a 600 grit sandpaper to provide adhesion between the part and the paint.
Painting should be done in steps where you apply a thin tack coat first and then full coats. Apply 2 or more full coats to get good coverage.
Allow the part to fully dry before you reinstall it.
Plastic Trim Parts
are found in your interior dash or console, ground effects, Fender Guards and openings for wheel wells and many other places inside and outside of your car.
To restore a plastic trim part you need to clean the surface and then use a wax and grease remover. Once the area is clean you can apply a plastic primer or adhesion promoter solution.
This will prepare the plastic part by opening up the pores or slightly melting the plastic on the surface to promote a good bond between the paint and the plastic.
If you are using a primer it is important to use very thin coats so you don’t fill in the texture on the part.
The paint that you apply should also go on thin and then a clear can be used in some situations.
SEM and other manufacturers produce premixed paints that will match your interior and exterior trim parts. Some of these paints are for vinyl and some are for other plastics so read the directions because different steps need to be followed for each plastic type.
When working with plastic bumpers you need to use a flex agent if you want to paint a black trim part the same color as the rest of the car.
Work with your paint supplier but also go to the paint manufacturers website and read their directions.
Final Note
When you choose to restore a part instead of replacing it you should understand that paint will not last the same way that colors embedded in plastic do. If the part is flexible and prone to damage like a bumper guard or door guard then you will probably end up having to repair it again in the future.
The fact is no matter how good the paint is and how well you apply it restoring a part will never be the same. The idea is to reduce cost and provide a respectable looking part that should last you for a few years.
The key to a good job is cleaning the part well and thin coats.