Polish Car – Identifying Scratches

    Published: 06-16-2009
    Views: 199,948
    Automotive expert Mark Boudreau demonstrates how to identify scratches on your car in order to polish them out.

    Mark Boudreau: Hi! My name is Mark Boudreau from Spectrum Auto Painting & Collision Center and today, I am showing you how to buff scratches and scuffs out of your car by hand and with the machine polisher. Right now, I am going to show you how to clean the affected area, determine whether it is a scuff or a scratch and then something called the fingernail test. First, cleaning the affected area of your car. Now, before we do any polishing or buffing, we need to make sure that the panel we are working on is clean, if not, you risk grinding contaminants into the affected area, worsening any problems rather than making them better. You also want to make sure that the panel was cleaned, so you can properly identify any scratches and scuffs.

    In the case of this car, I have already washed this car with dishwashing soap, not car wash soap, but dishwashing soap. The reason being it's going to remove any wax on the surface as well. We want that off during any polishing and buffing process. So I have washed this trunk lid or deck-lid and dried it off. Now, we are ready to inspect it to determine what kind of damage we have. Now, this panel has damage in three areas. We have a scuff, some very light scratches and some medium scratches over here and another scratch over here that we are not sure about. How do we know the difference between a scuff and a scratch? Now, a scuff is something that is laid upon the paint, meaning perhaps, you were moving groceries inside and a milk carton brushed up against the car and a little bit of the plastic was left on top of it or somebody lightly scratched your car with their bumper leaving a little bit of their paint behind. For instance, you might see green or yellow paint on top of your blue car, that is a scuff. It actually has not traveled into the paint surface.

    Then we have light scratches. Light scratches you can see when you looked down on your car and you can see light scratching, you still see that color, it doesn't look like any paint has been removed and they can range from very light, which can happen just by washing your car with the sponge and you might see swirl marks, to dragging something across the top of a car, putting a bag of groceries on your trunk or more severe damage where you see white around the scratch because of the clear coat on top of the color has been scratched.

    The last case is the scratch that has gone through the color and the clear coat down to either the primer or the metal. Now, how do we tell the difference between light and medium scratches and a scratch that has traveled all the way through the clear and color coat. Pretty simple, we do something called the fingernail test just like it sounds. You take your fingernail and you rub it across at a 90 degree angle to scratch. So, we have some scratches here; my fingernail is not catching. The key is if your fingernail catches, you know you've got a very deep scratch and polishing or buffing is probably not going to take care of it. Refinishing the panel is most likely going to be required to repair that scratch.

    Got some light scratches over here, my fingernail is not catching. Now, we've got a scratch right here in the middle. Let's see what happens when I drag my fingernail across that. My fingernail catches. You might even be able to hear the little click click sound and makes my fingernail drag across. That scratch most likely is not going to come out with machine buffing or hand polishing. So, we are going to focus on our scuff mark, our light scratches and our medium to light scratches. Next, I am going to show you what the procedure is for removing a scuff mark by hand with polish.