Summer is tar, sap and bug season. In the summer months, insects are at full population, trees produce more sap, and the heat softens the asphalt, producing tar balls on tires. While tar and tree sap can be difficult to remove, they do not present a significant threat to your car's paint. Bug stains, like bird droppings, are very acidic and represent a significant danger to the beauty of your paint and trim.
Removing Road Tar
As you drive, your car is bombarded with small specks of asphalt, tire rubber, grease and oils kicked up by the cars and trucks in front of you. Left on your car's finish, these petroleum-based contaminants will firmly affix themselves to every exterior surface. Soap-and-water washing will do little to remove these ugly black spots.
To remove road tar, you need a solvent or strong detergent. Most commercial tar removers contain kerosene, mineral spirits or another petroleum distillate combined with lubricants to surround and buffer the road tar from your paint. Of the petroleum distillate products I've tried, I like Stoner Tarminator. A more modern solution for tar removal is detailing clay. If the tar is extremely stubborn on your painted surfaces, you can also use a paint cleaning polish, like Klasse All-In-One.
Removing Tree Sap
Removing tree sap from a car's finish is a bit more difficult than removing tar or bird droppings. Incorrectly removing hardened sap can scratch your paint. I've found that by hand rubbing the sap spots with mineral spirits, I'm able to easily remove the sap without damaging the finish. Mineral spirits acts as a solvent to break up and dissolve the sap.
If there is a large amount of sap on the car, or if the sap has been left on the finish for an extended period of time, it can be a lot of work to remove. For these cases, I discovered that going over the affected areas with a light-duty rubbing compound removes the hardened surface of the sap spots. Then I can hit the sap with the mineral spirits to remove it. The light-duty rubbing compound softens the sap so the mineral spirits can do its job. The goal is to use the least pressure possible, to reduce the risk of scratching the paint. After removing heavy sap, I always buff the treated areas with a good polish to clean up any marks created during hand rubbing with solvent. The treated area must also be re-waxed.
Removing Insects (Darn those little bugs!)
What's the last thing that goes through a bug's head when it hits your windshield? His rear end, of course! All joking aside, the head-on collision of that juicy June bug on your car's beautiful paint and trim is far from one-sided. As the bug's exoskeleton explodes, acidic fluids are firmly embedded in the surface of your car's paint.
Did you know that shellac is a bug byproduct? Think of it, that beautiful old antique table you love is covered with dried bug juice (yuck!). Bug splats on your car amount to little more than shellac mixed with nasty bug parts. Any attempt to remove the calcified remains without the use of a special cleaning solution could result in scratched paint.
The secret to removing insect remains is to loosen and dissolve them with a cleaner or solvent that will cut through the shellac. For bugs with a little extra grip, agitate the paint with a paint-safe insect sponge.
If you have a particularly large bug mess, I have discovered a trick that seems to work pretty well. If you use a pre-wax cleaner, such as Klasse All-In-One, apply a small dab to the offending bug splat. Next, cover the spot with a wadded-up tissue. Let it sit for a few minutes, then pinch up the mess and give it a soft wipe with the back side of the tissue. Voila! The bug mess is gone.
Paint Etching Caused by Dried on Insects
If heavy insect debris remains your vehicle's paint finish for more than a few days, the acid will etch the paint. In this case, cleaners will remove the insects, but the paint will have etch spot (dimples) damage. The only way to fix this problem is to polish the paint using a dual-action car polisher, like the Porter Cable 7424XP.
You can polish all day by hand and you won't make the insect etch marks go away. To correctly fix the problem you will need a dual-action car polisher, a foam cutting pad, a foam polishing pad, and Meguiar's Ultimate Compound. You might think that you can do the work by hand, but trust me, you can't. You'll rub, and rub, and rub and won't make a dent in the etch marks. Modern clear coat paint is too hard.
Your alternatives are to invest in a good car polisher kit, like this Griot's Garage Polisher Kit or this Porter Cable Polisher Kit, or hire a professional detailer to do the job for around $250 to $400. You'll save money doing it yourself.
See our Dual-Action Car Polisher Guide to learn more about safe car polishing.
After Removing Tar, Sap & Bugs
All of the chemicals used to remove the aforementioned road stains also remove your wax or sealants. After removing tar, sap or bugs, plan to spot wax or re-wax your vehicle. If you don't have time to wax right away, use a quick spray wax like Meguiar's Ultimate Quik Wax. This products is great for touch-ups or a quick waxing after the weekly wash.
Next in our Paint Repair Clinic Series: How-to Remove Swirl Marks.