Touching up Small Scratches
by Miq Millman, firstname.lastname@example.org
Do you have a small ding or scratch in your otherwise good paint job? If so, here is a technique I’ve used with good success for touching up such flaws:
I’m going to presume that the chip is down to the bare metal for this process. First, get some items to help you with the job:
- small bit of primer, compatible with the paint on your car
- color matched paint
- A very sharp #2 pencil with unused eraser on the end
- two or three extra pencils with unused erasers
- double sided tape or contact cement (cc preferred)
- 600 grit wet/dry sandpaper
- 320 grit wet/dry sandpaper
- 220 grit wet/dry sandpaper
- some organic cleaner (simple green works great)
- a couple of cotton tipped q-tips, paper shafts required
- optionally a magnifying glass
- spray cleaner (Aero Kroil is the best I’ve found) or rubbing alcohol
- empty shoe box bottom, cut to fit over area with chip.
- Polishing compund (not rubbing compound)
- cloth diaper if possible, or lint free terry cloth rag
Carefully clean the chipped area with the undiluted organic cleaner and examine the edges of the chip to see if they are loose edges to the chip. Probe the area carefully with the sharpened pencil point (the graphite point is soft enough to not damage the paint edges, and will come off with the alcohol or spray cleaner easily with out rubbing) to look for areas that are lifting up. Make mental notes if any areas exist, or if possible, remove them.
Cut a small circle of 220 grit sandpaper and glue it to the eraser on the pencil. Attach some 320 grit sandpaper to another pencil, repeat with 600 you’ll need both of these soon, so do them all together. Use this to carefully roughen up the edges of the chip and the exposed bare metal. Use the spray cleaner to remove the dust particles. The spray cleaners have a high rate of evaporation, so should not interfere with the paint.
Use the 320 to roughen up about a small area of paint outside the chip, about 3 or 4 millimeters should be enough. Use the spray cleaner to remove the dust.
Carefully pull _most_ of the cotton off one end of the swab. Just a minor bit is needed since you are using the paper shaft as well to apply paint. Dip the prepared end into the primer about 5 mm and dab the paint into the chip. Start at the center to create a dome of paint and pull it out to the edges. If there were loose edges of paint, try to get the primer under them as well as coating most of the roughened up paint. Leave about 1 mm of exposed roughened paint around the primer. The coat should be very thin. If the first drop didn’t cover the chip completely, in the next step, dip the swap deeper into the paint. But don’t over do it. It is much better to have too little paint in a layer than too much. Probably another 3 mm is enough. Allow 2 hours to dry (!). You’ll thank me later that you waited this long. take the shoe box and make sure that it can easily cover the area you just put paint on, trim it if needed to fit better. I use my car cover to hold it in place. This keeps the dust out while the paint is drying.
Once the paint is dry, use 600 grit to roughen up the surface and reapply another dallop of primer in the same manner. Let it dry another 2 hours.
Once the paint is dry, use 600 grit to roughen up the surface if you can see bare metal in the scratches, repeat the previous steps one more time. Usually two coats is enough however.
This time apply the color paint in the same manner, dip the sheared swab about 5mm into the paint, and place a drop in the center of the chip, then pull it out to cover the chip entirely. Spread out the paint to cover all the area that is roughened up. Don’t worry if you go over the area, it will be removed later. This layer of paint should be very thin, perhaps not even obscuring the scratches or some of the primer. That’s ok. Cover it with your shoebox, and let it dry for 2 hours.
Add another drop of paint and spread it out to cover the chip. The secret to this method is that you should never redip the swab when applying a layer of paint. If the chip is larger, dip the swab deeper into the paint this time, but only a little bit. Don’t worry if the chip is not covered with paint yet, follow the same method you did with the primer and each successive layer adds a bit more paint to the initial drop, until the area covered is the right size. Again let this layer dry for at least 2 hours.
Repeat the spreading drop of paint, 2 hour drying time, a number of times. The idea is to make the combined layers of paint ever so thicker than the painted surface of your car. I predict for a chip that is to bare metal, you will need about 2 coats of primer and 8 to 10 coats of paint. As always, more layers won’t hurt, it just takes a lot more time. The 2 hours between coats is imperiative. DO NOT SKIP THIS STEP.
By now you should have a small blister of paint a fraction of a millimeter thicker than the paint job on your car. Let the last coat dry about a week before doing the next step. Really.
Wrap the diaper around your index finger and make sure the tip is covered. Use this to apply a small amount of polishing compound to the ex-chip, and polish the area in small circular motions. Use a clean area of diaper when the diaper is paint colored. Examine the blister of paint to see if it is blended in to the correct layer yet. Once it is, clean your car like normal. Then wax it with a good hard wax of your choice.
Yes this is a labor intensive process, but when you consider how much money a new paint job is going to cost, its pretty minor. I have used this method many time (unfortunantly) and you would be hard pressed to find the chips on the front of my car, even though it’s black lacquer, the worst offender for chipping and showing blemishes.