What you need to fix the scratch
When I find a deep scratch in my paint, I lose my mind. They’re annoying to look at, expensive to repair, and open up your paint to future rust problems if left untreated. Here are the items you’ll need for this task: isopropyl alcohol, shop towels, touch-up paint, small touch-up brush, foam block, filler putty, squeegee, and a paint leveler.
Start by cleaning the scratch
For the purposes of this demonstration, I’ll be working on a scrap panel hood I use to practice compounding and polishing techniques. First, I’ll use a screwdriver to mimic the damaged caused by a tree branch, shopping cart or bicycle handle. These scratches are usually deep and require more than just a simple touch-up. To start, clean out the scratch with rubbing alcohol to remove any leftover wax, especially if the gouge occurred after a recent wax or sealant session. Due to the severe depth of the scratch, touch-up will not be effective nor efficient when filling in the crater. For this, a glazing spot putty will fill the void or crater before applying touch-up on top of the dry putty.
Filling it in
Squeeze a bit of putty next to the scratch, then use a small squeegee to spread the putty into the scratch and allow the glaze to dry for two to three minutes. Once dry, wrap a shop towel around a foam wet sanding block, and apply liquid paint leveler to the towel. The leveler will remove the putty surrounding the scratch, but leave the excess putty within the scratch. Gently wipe the towel across the putty to remove small sections at a time. Use light pressure as the goal is to leave the scratch full of putty and it may take you a few minutes to get this done properly. When done, the scratch should look like a thin red line the length of the original damage.
Applying the paint
Next, use touch-up paint from your dealership or specialized online retailers and a very fine brush. Apply the paint to the red putty by dabbing, not brushing or wiping. Cover the area with a thin, light coat and allow it to dry over night. If more touch-up if required, add one more thin coat or simply apply clear coat on top of the dry touch-up paint. The main purpose of touch-up, especially for deep scratches is to protect the paint from future corrosion, however, if done correctly, the by-product of this process cosmetically makes the scratch less annoying to look at.