How to Spot Paint Your Car

Spot painting is an art form when it comes to color blending panels with base/ clear paint products. Spot painting is a time-consuming process and a very delicate operation if everything is not done in just the right order and with extreme accuracy you will be left with poor results. For this article I’m going to be using a rear quarter panel on a full size car for example and the dent or damage that has been repaired that is closest to the taillight and we are going to want to blend the panel from the primer to the existing color of the rest of the quarter panel closest to the door. I will be typing down the tips in chronological order of the procedure of spot painting the panel.

** First of all you need to make sure that the damaged area has been sprayed with three full coats of primer before spot painting and when sanding was done the surface was not broken through to the substrate base coat. When spot painting you are not able to use sealer because if you did it would cover the whole panel or if you only used sealer on a 1′ x 1′ section of the rear corner it would give you an inconsistent surface finish because there wasn’t sealer on the rest of the panel (basically the edges of where you stopped spraying the sealer would appear to be dry sprayed with texture). So we’re not going to be using sealer when spot painting, your primer will act as your sealer; so you need to make sure that you did a very good job of priming the surface and that the primer is of a consistent thickness throughout the damaged area. If you have broken through to the base coat then you need to re-prime the area again because this could cause lifting or a halo effect to the base coat after the clear has been applied when spot painting.

** After masking off the entire rear quarter panel to prepare for spot painting you’re going to want to wipe it down with a paint degreaser such as Scat and wipe off the entire panel with a tack rag before you get begin your spot painting ( on another note the preparation of a spot painting surface to be painted, it should be wet sanded with 600 or 800 grit sandpaper, this way you get a smooth surface; but at the same time it’s rough enough for adhesion; and do not break through the clear into the base coat anywhere on the panels-this will really screw up your spot painting job.)

** Making sure that you’re using a 1.2 or 1.3 mm gun to for applying the base coat to the panel to be spot painted; it is important, especially for the manner that we will be spraying. For clear you’re going to switch over to a 1.4 or 1.5 mm gun tip on this spot panel. You will begin spot painting by only covering the area of the grey or black primer with color, this will be your first coat.

** For your second coat you are going to want to reduce the base coat by adding half as much more reducer as you used on the first coat, when spraying the panel you are going to want to travel about 6 to 8 inches past the primary area while still covering the primary area. What we’re attempting to do is blend the spot panel and make a smooth color transition.

** For your third coat of base coat you are going to want to reduce the base coat slightly more, making it translucent on your mixing stick when your mixing the base coat. Now that you have mixed it up correctly you will want to exceed your prior 6 to 8 inch spray pattern by another 8 to 12 inches, as you come closer to the original paint color on the rear quarter you will want to flick your wrist in a manner so as to just barely flash on a light amount of paint, however on the damaged prime area you will want to put on a wet coat. So effectively in layman’s terms what you’re going to want is a heavier amount of base coat closest to the damage near the taillight (to cover the primer completely) and a lighter amount of base coat on the rear quarter as you come closer to the door. Remember what you’re trying to do is spot blend the panel (keyword “spot”, you’re just trying to cover the spot of primer and transition it to the surrounding areas). You should have approximately 1 to 1 ½ feet of area on the rear quarter closest to the door that you have ultimately not sprayed with any base coat.

** Now that you have applied the base coat and two thirds of the panel is coated heavily from the tail light transitioning to lightly coated towards the middle to end of the rear quarter closest to the door it is time to apply the clear coat.

** There are no tricks necessary when applying the clear coat to a spot panel other than making sure that you change your gun tip to 1.4 or 1.5 mm. Apply three coats of clear while waiting approximately 10 to 12 minute intervals to allow the clear to flash off (or tack off). Once you have done this you have completed the task of blending the rear quarter panel. Spot painting can be done on any panel, but you need to pay close attention to what your intentions are when you’re spot painting. If you are replacing a front fender and you need to paint that to blend it with the rest of the car then you’re going to need to blend in a fashion in which we just did all the way to the middle of the front door.

**** Another tip for spot painting is that when you go to the automotive paint store make sure to bring along with the color code (from the door jam-don’t forget the VIN number also) a sample of the existing paint that is on the car such as a gas tank lid (this is so the can use a color camera for an exact match). Sometimes it can be hard to tell if a vehicle has had an all over paint job or have been spot painted before if it was refinished by a quality body shop. If the entire car has been repainted you can best believe that the color code in the door jam is not the same color as the car, this can be caused by numerous things such as the color of the primer used, the color of the sealer, and/or a different brand paint system; there can be many color tone differences from paint system to paint system, especially when dealing with metallic colors.