Bumper Scuff Repair, Part 4 Clearcoating
Posted by Jay Schneider. Filed under Automotive.
December 1, 2009
Spraying the Pearl coat and clear coat
Once the allowed flash time for the basecoat has lapsed, it is time to clear. In this case a Pearl coat is sprayed prior to the final clear coat. Pearl coats are very difficult to master, some say impossible, because they are very high in solids. That is to say the more pearl that is laid down, the darker the repaired area will be. With this in mind, be very careful as to how much material you spray. Between coats, look at the area from different angles looking for variations in color and hue making sure you keep the material in the spray gun well mixed preventing the solids from collecting at the bottom of the paint cup. Failure to accomplish the above will promote the formation of unsightly stripes in the paint. During the last coat of pearl, I like to pull the spray gun back away from the work and dust the area with a very fine coat of paint. This step will blend the area should there be any definitive color variations. Mix enough pearl coats for the area to be sprayed and apply enough pearl to match the color of the surrounding area.
Flash off times for Pearl Coats range from about 30 minutes to 1 hour at most. While this is occurring, thoroughly clean the gun and prepare for the clear coat. Mix the clear coat according to manufactures recommendations and sprays the clear coat per manufacturer’s instructions. One way to blend the area and hide the repaired, sprayed area is to use what is called a “Hot Reducer”. There are generally two ways to blend a sprayed, repaired area – 1) A two gun technique and 2) A one gun technique. To blend the area using the two gun technique, upon the final coat of clear coat, you’ll previously have set up another spray gun with the blender in the cup. Immediately after the last coat, spray the outer perimeter, halo, where the wet paint meets the dry or unpainted area with the blender. This technique flows the wet paint into the dry paint making for a nearly perfect blend and renders the repaired area unnoticeable. The one gun technique is applied in the same fashion but when the last coat of clear is applied, you will immediately empty the guns’ cup and fill it with the blender and spray it in the same fashion- that is around the halo or where the wet paint meets the dry paint. This technique takes practice to master but once mastered leaves a finish that requires little sanding if any, and less buffing.
Next discussion – Color sanding and buffing the end result.
Scott S. Mc Lain
Sales & New Product Development