The factory paint on the plastic fender flares of my 1986 Cabriolet had deteriorated to the point that all four had flaking and cracking of the original paint. The damage was primarily on the upper portion of each wheel arch. That's the area that has been exposed to 23 years of often blazing hot Texas weather. Pretty sad looking. Time for a Cabriolet rehab to match the fresh, new top.
Sheet metal screws and washers hold each flare in place and are easily removed. Bag them so you don’t misplace them. Expect to find some silty dirt packed inside the lower 6-8 inches of the flare’s interior. Some cars may have an adhesive seal between the car body and the flare. Mine did not.
Clean out the agricultural samples with a strong water jet. Perhaps use a small, stiff brush and something like Simple Green. Remove any tar or road oils from the components using mineral spirits and a rag. Do not paint over dirt and grease. The paint does not stick well, nor very long, to these materials.
I began the paint prep work by wet sanding the flares with 3M 220 grit Wet-or-Dry paper. This is the most time consuming part of the entire job. Initially, I was sanding clear coat. You will know when you have worked down to the paint when the swarf (sanding debris) is paint-colored rather than the milky look of the clear coat.
The area on the top of each flare was where I had the most damage. It was necessary to sand down to the base substrate black plastic in the serious areas. Blend the sanding to create a smooth transition between plastic and any solidly anchored paint. If the paint is still smooth and well bonded to the plastic, sanding prep is all you need. Not necessary to remove all the color.
When you feel like the flare looks good, sand some more. It’s really difficult and depressing to have to go back and begin again after you’ve shot primer and discovered the not-so-smooth sanding prep. Solid work in preparation will mean far less time required for color finish.
Rinse the parts thoroughly. After drying, give the parts a quick wipe down using lacquer thinner. Do not spend too much time with the lacquer thinner on the primer as it may begin to soften. Avoid oily fingerprints and any toweling that may be contaminated with oils or a silicone product. You do not want to deal with fish eyes. Tack rags are good but watch for bits of thread.
I chose to prime the flares using a rattle-can. The flares are small enough that setting up a paint sprayer just for primer may not be worth the trouble. Stop by an auto body supply and buy some quality primer. SEM is a brand that I have had good experiences with. For the plastic flares, I selected SEM’s #39133; a flexible primer-surfacer designed for automotive plastics. Perfect, but pricey.
Apply several medium-wet coats rather than one heavy coat. Allow 5-10 minutes drying time between coats. After about an hour, depending on temperature and paint film build thickness, the product can be wet sanded.
3m 320 grade Wet-or-Dry, used wet, smoothed the primer and did a good job of blending the surface areas. A little bit of sanding through the primer is not a bad thing. Simply finish the initial sanding and shoot a little more primer. Repeat with the 320 paper.
Wet sanding is the preferred way to sand down primer and paint. Use lots of water to keep the surface flushed clean of sanding debris. By wet sanding, your paper will remain clog free and the job will go faster with better results. A five-gallon bucket of water and a squirt bottle are all you need. Rinse the part and paper often.
Keep in mind that sandpaper will wear out. When it quits cutting well, replace it. Using worn out sandpaper will only add unnecessary time to the job plus you’re just polishing the high spots. This is false economy.
Body shop suppliers offer many varieties of sanding blocks. A hand-sized hard rubber block works quite well on flat surfaces but the fender flares seem to be lacking many flat areas. There’s a flexible sanding pad, too. A dense gray foam pad backed by a harder black rubber. This pad is able to conform to subtle curves. It became my preferred weapon.
Each of us has different levels of patience and only so much sanding capability within. Sanding burn-out occurs when you say to yourself, “That’s it! Good enough.” Perhaps it is, or maybe not. Good materials will help you do better work faster. The final paint will tell all.
Examine your primer work closely. Low spots, usually very small and not easily seen, will show up under close scrutiny as slightly darker specks or scratches. This occurs because the defects are below the surface of the recently sanded primer which now has a lighter color.
You have a couple options on taking care of the small flaws; keep sanding -not a bad idea- or apply a very thin skim coat of glazing putty (sometimes called spot putty) over any small rework areas. Resist the urge to slather on more primer.
The flares on my Cabriolet had a “pebbly” texture but only in some areas. May just be the way the plastic was molded. Sanding off the old finish in the damaged areas knocked down the tops of the texture. The primer-surfaced filled most of the low areas and the glazing putty took care of the rest.
After all four fender flares are primed, sanded and quality inspected, it’s time to get out the spray gun and prep for the color coat. Insure that your parts are completely clean. This is critical for solid color bonding to the primer.
The original paint on my fender flares was a color/clear coat finish. I elected to use what I am most familiar with which is a single-stage PPG acrylic enamel with a gloss hardener additive. I have painted aircraft with this product and find it to be very satisfactory in performance and durability. Clear coat finishes are fine, too. Just added cost. Go with what you are most comfortable with.
Here’s an easy way to save a substantial bit of money on a paint purchase. A quart of PPG Cabriolet Titian Red in acrylic enamel, a small tin of the hardener and a quart of reducer came to $133.00 with the 20% body shop discount. I don’t operate a body shop. Ask for the shop discount and odds are, you’ll get it if you are paying with cash.
The price made my eyes water a bit and I told the salesman that I’d have to give it some thought. Thought, as in, “I’m gonna look elsewhere, pal.” He then responded with a suggestion that I use the PPG value line Omni AE paint product. Same stuff. Different label. Total cost was $55.00.
After all the prep work of cleaning, sanding, priming, more sanding, spot putty, more sanding, more primer and even more sanding... I’m ready to get some color on the flares and quit for awhile. If you have been diligent with the paint preparation, the final color will look better than factory and you can take pride in the effort.
Use a proper reducer with the paint. Ambient temperature will determine what reducer you will need. Ask the color house people. Do not be tempted to cut corners here and simply throw in some lacquer thinner. Not worth it.
Should you be doing the spray gun work, then you’ve probably done it before and there’s really no need for another lesson. If lacking spray gun equipment, you might wish to enlist the aid of a friend and his spray equipment to assist with laying on the color. You will still have a substantial personal labor “investment” in the completed job. The actual painting took me less than five percent of the total time expended on this project.
And while the paint is drying on those great looking, refinished fender flares, you should offer to clean out the spray gun. Then take your friend for a burger and a beer. Good job. Looks great!
And this, folks, is the Cabrio's fender flare paint shop at Planet Parkside. Believe it. Nothing exotic or fancy, just functional. Setting up the sun and wind screens, gathering all the support materials and confirming the morning's temperature and humidity took almost two hours. Shooting color on all four fender flares was completed in less than twenty minutes! The Hummingbird feeder is actively used. While I was shooting color, a female cruised by and was high ticked that the canvas drop cloth was blocking her breakfast buffet.