| The Refinishing Process |
| The Refinishing Process |
From "Trade School"
episode DTRS-101 |
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Jason has now repaired the damaged surface areas of a 1975 Jeep CJ-5. Here, he continues to demonstrate the skills needed in the automotive refinishing industry. He primes and paints the Jeep, adds custom ghost flame graphics and finishes with clear coat. The flame graphic technique is explored in the following segment ....
Basic Tools:
Dual Action Sander
Masking Paper
Plastic Sheeting
HVLP gravity feed spray gun
Sanding BlockHe first preps the vehicle’s entire surface by sanding it. He uses a dual action sander with 320-grit paper. This gives the surface a slightly rough, uniform surface suitable for primer. The vehicle is then hosed with water to remove dirt particles.
Jason rolls the Jeep into a professional-style spray booth. The booth is well ventilated to ensure a clean air environment. He begins masking off areas that he does not wish to have painted. A combination of masking paper, masking tape and some plastic sheeting do the trick.
Jason then cleans the painting surface with a grease and wax removing solvent and a lint-free towel. This removes any fingerprints or oils that may remain on the surface. He removes any lint or dust that remain using a tack cloth.
SAFETY ALERT: Even with access to a ventilated spray booth, a respirator must be worn when painting to avoid the inhalation of dangerous fumes. Safety glasses are also recommended. Because there are areas of exposed surface metal, Jason uses a HVLP (High Volume-Low Pressure) professional gravity-fed spray gun to apply a coat of epoxy sealer. The sealer’s purpose of this is to create an anti-corrosive surface that primer will stick to (primer does not adhere to metal well). He sprays heavier on areas where body filler was used to ensure a complete seal. This application is allowed to flash, or dry for approximately 10 minutes. Jason then applies 3 coats of primer using the HVLP gun. A must when painting over repairs with body filler, this layer advances the leveling of the surface and readies it for guide coat and wet sanding. Each layer of primer requires five to ten minutes of flash time between applications.
Jason then sprays a light mist of guide coat over the surface. The purpose of guide coat is to identify any high and low spots that will need to be sanded. The guide coat does this by showing a contrast from the color of the primer. Jason wet sands the entire body of the vehicle to create a smooth surface for the base paint. Jason uses a sanding block with fine 400-grit paper and constantly squeezes water from a sponge over the block while hand sanding. Wet sanding over a high spot exposes bare metal, and wet sanding over a low spot will leave guide coat. The surface is level if primer is all that remains. The water helps to wash away accumulating grit and dirt from the sandpaper, which prevents scratching the surface. Then, a urethane-based silver metallic paint serves as the base coat. With the HVLP spray gun, Jason applies three layers of base coat to the vehicle with a flash time of ten minutes between each application. The final coat requires 20 minutes of dry time before adding custom flame graphics. (A TECHINIQUE FOR CREATING FLAME GRAPHICS IS EXPLAINED IN THE NEXT SEGMENT)
Jason applies two layers of clear coat using the HVLP spray gun. Clear coat gives vehicles a glossy, protective finish. The first application is allowed 10 minutes of flash time. After the second layer is applied, the vehicle is heat-treated in the spray booth. The vehicle is treated for 25 minutes at a surface temperature of 140?. This speeds up the final dry time, allowing the clear coat to harden. (Flash and heating times are determined based upon the clear coat manufacturer recommendations)
The masking is then carefully removed and the accessories are reattached. After five weeks of hard work, the vehicle has been transformed from eyesore to eye candy. The finished project is a wonderful tribute to its previous owner.
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