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Little Black or Brown Spots on Car


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Brown speckles began appearing all over my white yukon. The dealer said rail
dust, fix with claybar treatment, $300 thank you! The spots started to come
back within 2 weeks. The GM dealer now does a tap dance and with lot of BS.
Who can I take this vehicle too to find out what is really happening to
this paint job. No other cars where I park this car are similarily
afflicted. Thanks


I am guessing you are in the mid-atlantic region. I too have seen the little black spots on my car. My spots looked like little balls of tar and you can scratch the tops of the ball off, but a small spot still remains which is hard to remove? Is this what you are seeing? If it is, you problem is not rail dust, but Artillery Fungus ! Yes I said fungus. In the mid-atlantic region there has been a real problem with this little known fungus which shoots a sticky liquid from it’s insides up to a couple of feet away. The wind can then carry them even further. They grow in rotting wood and mulch. It may not be from your place of business, but rather from your house, or even the gas station you may visit every morning for coffee. (if they have mulch around)

For more information, Dr. Donald D. Davis of Penn State is currently doing research on this annoying fungus

My method of removing the spores is this… I wash the car first, then use bug and tar remover with a 100% cotton towel, as to not scratch the paint. This works well with spores that have not been on the vehicle for a long time. Older spores need to be removed with a clay bar, as your dealer did the first time. You can purchase a clay bar kit in most auto parts stores, under the Mothers brand. A word of caution with the clay bar, keep folding it over, exposing new clay, to prevent built up dirt from scratching your paint. It’s a great way to clean your car, but if not used properly, it becomes like sand paper. I have also had limited success with latex paint remover sold under the M-22 label, but I do not believe this is sold anymore.

To prevent the spores from coming back, you can try to re-mulch the area that you park next to, or replace the mulch with stones as I did at my business.

Good Luck,


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Posted: 19th August 2006  |  Author: Kevin Schappell  |  Category: Body, Car Care

3 Responses to “Little Black or Brown Spots on Car”

  1. Sqrach says:

    I have a tip you may want to add. After going through a high pressure wash and super turbo drying the spores stayed. However, if you take a micro fiber towel you don’t need to use any force. You can literally just hold it by the edge and lightly drag and glide it along the surface. This will basically vacuum up the spores. Micro fiber is much better to use over cotton. I don’t know if it’s the design or maybe the electrostatic (especially after wash/dry) or maybe both. My car is black so the actual marks I have to work on. As far as removing the spores this seems to remove most if not all in a minute or two. No liquids. Just a dry cloth/towel and then I just shake it and they fall off.
    I tried using detail after with a micro fiber pad and it picked up any remaining ones. I was disappointed at first because I thought they were gone, but now I realize this was step 2 in getting them gone all together.
    Microfiber is awesome. Really, look on wikipedia, they show up close why it’s better than cotton. I’m trying to learn about these spore things as much I can so I’ll let you know if I find better solutions.

  2. Maybe a little polishing will help? Burnishing the paint’s finish is a final perfecting step wherein a pad with zero cutting capability is used with an ultra fine polish ultimately at very slow speeds.

  3. Jim says:

    Black Spots Removal

    My Toyota Camry is a light tan color and it got coated this summer with about 1000 spots from the Artillery Fungus. I tried removing the spots with mouthwash on an area of a paper towel and used elbow grease and a thumbnail to help the process. The spots came right off, but removing the residual took about 15-20 seconds per spot.

    Then it started to mist (light rain) and I was about ready to call it quits. After a few minutes, I noticed that they came off easier. Later, I just used my thumbnail. The residual came off very easily as a black powder in the water. I used paper towel to wipe off the remains. Removal time was down to two seconds for most spots and the few tough spots took up to 10 seconds. The next day was sunny and again about 55F and I had to remove the few spots that were missed. They smeared and had a lot of residual and again took about 20 seconds to remove.

    Summary: Work in the rain!

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