PPG, Color Blending

Blend Preparation

Proper preparation in blending is always important. After making the required repairs to a vehicle and priming and sanding as necessary, you are ready to prep for a blend. Before spraying any color on the vehicle, the area surrounding the spot to be painted should be thoroughly cleaned and sanded with 1200-1500 grit wet or equivalent. Sand just beyond the area where color will be applied for a single stage blend. For basecoat, prep to the ends of all of the panels involved, or at least to the area just beyond where the clearcoat will be applied (in the case of a clearcoat blend).

Color Blending Technique - Single Stage, Basecoat

In most cases of blending basecoats, each successive coat of color is extended a little beyond the previous coat. In especially challenging situations, the use of a basecoat color blender will mask any color transition in the blending process.

When a spot repair is close to an adjacent panel, blend the color into it. If an entire panel is painted, blend into the major panels on all sides of it. For a single stage color, step it out a couple of times, use a blending solvent on the edges, and polish it when dry.

Unless you are spraying lacquer, an "adhesion promoter" is not necessary. Just apply the basecoat or single stage urethane directly over the primer or sealer and out onto the surrounding area as you blend.

Other tools available as an aid in basecoat color blending are DBU 500 for DBU colors and DBC 500 for DBC colors. These are unpigmented basecoat resins. After reducing and adding color blender to the basecoat, it is sprayed on the edge of the color blend area to help ease the refinish color into the OEM color for a smoother transition. It is especially useful on very high hiding colors since it reduces the hiding power of the color it is mixed with. That allows for a more translucent progression in the blend.

Color Blending Technique - Tri Coat Systems

The majority of multistage colors today can be successfully repaired using more conventional spot or panel repair procedures.

On a spot repair, first apply base color and blend edges. Next, apply midcoat and blend edges. The use of color blenders (DBU 500 or DBC 500, based on the chosen system) will help in the blending of base color and midcoats.

The same basic steps and tools used for blending on spot repairs can be used in panel repairs as well. First, apply base and midcoat color to entire panel. Second, blend base color. Third, blend midcoat.

Try and keep the repair and blend areas as small as possible. One way to accomplish this is to use a two gun method for blending the repair. This can be done with both base color and midcoat blend edges.

Here is an example of a midcoat blend:

Gun #1	contains regular reduced midcoat.
Gun #2	contains a mixture of midcoat color and color blender to make it more transparent.
Use Gun #1	to apply the regular midcoat to the main repair area. Keep the midcoat well within the repair area.
Use Gun #2	with the midcoat/color blender mix to extend the midcoat blend edges.