On the BMW 3 Series models from 1990 to 1991, the exterior trim was updated slightly to receive new body colored front and rear bumpers as well as a blacked out window trim instead of chrome as on the early models. In my opinion, this was a huge improvement of the looks and character of the car. My car was manufactured right at the cutoff between years, so while it does have the body colored front and rear bumpers, it does not have the blacked out window trim. Instead it features the chrome trim. I’m not a huge fan of chrome trim on cars. In order to keep it shiny, it requires constant polishing and cleaning. In my case, the chrome trim had oxidized; leaving a hazy, bluish appearance that would not shine no matter what I did to it. Believe me, I’ve tried everything from Bon Ami to toothpaste. Nothing worked. So I decided to simply go ahead and paint them black to complete the look of the later cars.
The first step is to wash the trim thoroughly. You want to remove as much surface dirt as possible. Just use soap and water on this. Harsh chemical agents such as acetone or thinner may spill onto the paintwork and damage the vehicle’s finish. I elected to paint the trim while still installed on the car. I could go ahead and remove the trim, however I run the risk of bending or breaking it.
The next step is to lightly sand the chrome trim with 600-grit sandpaper and a little bit of water. This will rough up the surface enough to allow the paint to adhere to the chrome. Just use light pressure. Once you have sanded the trim, you should notice that the chrome appears to have a dull finish. This is exactly what we want to see.
Now get a hold of some painter’s tape. This is a blue tape that has a low adhesion point. We want to use the painter’s tape because it will not damage the surrounding painted surfaces of the car. It has just enough stickiness to stay on the car. Now mask off around all the chrome trim. Use newspapers to cover the windows and body around the area. It’s a good idea to leave and excess of tape around the edges of the trim. This way we can either trim away what we don’t need with a razor blade or tuck the excess under the trim. Just make sure you mask off everything. Don’t skimp on this.
Now we are ready to paint the trim. There are many paints out there on the market for painting trim, however I have found that the best paint for this is Wurth. This stuff is easily the best spray paint I have ever used. It flows smooth, does not run and dries quickly. This is also the paint that the BMW factory uses to finish wheels and trim. It is also available from Pelican Parts (shameless company plug, sorry.)
I decided to use Wurth’s Satin Black Trim paint for this. It is designed to be used on chrome surfaces. Before you begin to paint, make sure that it is at least 70 degrees F. outside and not over 90 Degrees. This will make sure that the paint flows correctly. It if is too cold or hot the paint could run. Now, shake the can until the mixing ball inside starts rattling and shake it for at least a minute. I usually shake it for a good 3 to 5 minutes to make sure the paint has mixed. It’s also a good idea to shake the can in between strokes to keep the paint mixed. Now we are ready to begin spraying.
As with anything else, painting anything takes time and practice. It is an art form mastered only by a few. (That’s why is costs so much to paint a whole car!) If you have never painted anything I suggest you practice your technique on a scrap piece of metal. The key here is control of the flow. What you want to do is keep a steady hand about 8 to 10 inches away from the surface and move the can parallel to the surface you are painting while moving the can across the surface. Try not to arc the can as you spray. It’s also a good idea to wipe the surface you are painting with what is commonly referred to as a tack cloth. This is a rag that will collect any particles of dust that may have landed on the surface. It’s also a good idea to paint in a large dust-free environment with plenty of ventilation, or you may end up stammering and stuttering like Ozzy Osbourne. Paint contains fumes that can cause brain damage. Use common sense. (I must take this opportunity to show my everlasting respect to the Ozzman for using him as an example)
Now start by spraying a light coat over the trim around the whole perimeter. Don’t worry if it does not get over the whole trim. This first coat is what is called a tack coat. This first coat will provide the next coat with a surface to adhere to. Let this first coat dry for an hour before continuing.
After an hour, go back and spray the next coat. This coat will cover everything. Make sure you paint evenly and do not arc the can as you paint. Keep it 8 to 10 inches away and parallel. Now let this coat dry for three hours. After three hours, spray one more coat around the perimeter. This will be the final coat. Now let this coat dry overnight.
Once fully dry, start to remove the masking tape by grabbing one edge and peel it AWAY from the car at a 90 degree angle. This will prevent you from pulling off any of the paint on the trim. Go SLOWLY, and remove all the tape. Once all the masking has been removed, look for any overspray that may have gone onto the body or windows. If it has gone onto the glass, very carefully use a razor blade to scrape it off. If it has gone onto the body, Use car wax to remove it. Just use a very light amount and buff the spot until the paint is removed. It’s probably a good idea to wax the whole car anyway now to accentuate the freshly blacked out trim.