Arc & spot welding
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Car enamel colors
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Car paint glossary
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Cleaning car upholstery
Infra-red paint drying
Interior automotive trim
Painting over paint
Paint surface preparation
Refinishing paint tips
Safe car spraying
Sanding, striping, rubbing
Shrinking sheet metal
Not finished yet:
Any rust spots or breaks in the finish must be sanded out to form a feather edge with the old finish. Then spot glaze these places with a combined surfacer and primer. When dry, sand to level off with the rest of the finish. Deep, sharp breaks in the finish should be spot puttied and sanded smooth.
Now spray both sides of the fenders and hood and the surfaces of the body with one coat of combined primer and sealer. When this is thoroughly dry, spray on two coats of surfacer. After this has dried it should be sanded down with fine sand paper and all dust blown away and the surface wiped carefully.
From this point on, the refinishing job is identical with the procedure outlined for refinishing a car from the metal out.
While refinishing over the old finish reduces costs somewhat, there is almost as much rubbing as when building up a finish from the bare metal. And rubbing takes time and costs money.
Finish manufacturers have recognized this and have produced lacquers and enamels that can be used with practically no rubbing. Such refinishing is popular with car owners and in the used car departments.
Such refinishing is invariably done over the old finish. Do not skimp the cleaning job on chassis and motor. Remove door handles and other outside hardware and also wheels. Sand down all surfaces with fine sand paper. Blow off and wipe away all dust.
Touch up all bare metal spots with primer, and when dry give the whole job a coat of combined primer and sealer, sprayed on. If the old finish is very rough a coat of surfacer will also be needed.
Whenever spraying over an old finish, the use of a sealer is very important. This sealer forms a bond between the old and new finishes and keeps the following coats of lacquer from softening the old undercoats. If the undercoats soften, several undesirable things happen. The finish may become roughened—"alligator" surfaced as some call it. Or the finish may not dry as quickly as it should. And if a very heavy first coat of lacquer is sprayed over the old finish, the whole thing may run or sag badly.
After sanding the last undercoat, spray on two coats of black gloss lacquer. Then mask the fenders, splash aprons and other parts that are wanted black on the finished job, and spray the balance of the car with two or three coats of gloss lacquer in the desired colour.
This lacquer need not be rubbed, as it dries with a gloss. However, this gloss can be improved by spraying on a light coat of thinner. The under parts should be sprayed with a coat of chassis black, the body striped, and the job reassembled. Then it may be polished to raise the gloss if desired.
Refinishing right over the old finish is so popular in many sections—and for many reasons—that the step-by-step procedure of two of the outstanding manufacturers of refinishing materials is here given.
From the Duco instructions come the following:
Class B job
Instructions for application of Duco finish over old finish.
And where the cheapest kind of refinishing job is wanted —especially for cheap used cars— Duco advises as follows:
Corresponding refinishing jobs done with Opex lacquers—a product of The Sherwin-Williams Company—are handled as follows :
Opex method no. 4
Over old paint or varnish
The success of the application of Opex Enamel over the old paint and varnish depends entirely on the method of application, the condition of the old paint and varnish, and the care of the operator. Thousands of cars have been successfully finished in the following methods over the old finish. We list three methods, each of them having its special interesting feature.
It must be definitely understood, however, that these systems for over the old paint are not offered as a cure-all. The old paint must necessarily be in good condition. If it is peeling or too badly cracked, the paint must be removed to the bare metal. However, for a quick and less expensive method of finishing we know that this system is entirely satisfactory.
Clean and sand off the car thoroughly. All loose paint, grease, oil and dirt should be removed. The adherence of the product to the old paint will be satisfactory, providing rust, grease, dirt, oil are eliminated. However, if you apply Opex to paint which is almost ready to fall off, there is no reason to expect that the new finish is going to hold the old on. Many refinishers are using ammonia to clean off the varnish and then sand off the remaining colour varnish.
Apply one coat Oil Metal Primer and Sealer No. 12 or Opex Clear Binder No. 67.
Apply one light dust coat of Opex Binder Surfacer Gray, Light or Dark, reduced with equal parts of Opex Binder Thinner No. 2. This material dries for recoating and sanding in one hour or more.
Apply heavier successive coats, depending upon the condition of the original finish. Usually two or three coats of Opex Binder Surfacer Grey, Light or Dark, are sufficient to give a foundation which, when sanded out, leaves a perfectly smooth finish ready for the application of the Opex Enamel.
Sand to surface with fine sandpaper. Deep cuts or scratches should be avoided. A hard, glossy surface should be secured.
Apply Opex Enamel two or three coats reduced with Opex Binder Thinner No. 2.
Opex method no 5
For an even quicker and less expensive job the priming coat is eliminated in this method. Of course, if there are any rust spots, these must be sanded out bright and clean and primer applied to the bare metal where exposed.
Clean and sand off the body and car completely, taking all care suggested with regard to oil, grease, etc., as in Method 4.
Spray one very light or dust coat of Opex Binder Surfacer Grey, Light or Dark, reduced with equal parts of Opex Binder Thinner No. 2 directly over the cleaned and sanded body.
Apply successive heavier coats of Opex Binder Surfacer Grey, Light or Dark, reduced as above, until sufficient material has been applied to fill surface imperfections.
Apply Opex Enamel, reduced with equal parts of Opex Thinner No. 2 same as suggested in previous methods.
Opex method no 6
At times for the cheapest type of job nothing is desired but a freshening up of the surface after all bare metal spots have been touched up with Oil Metal Primer and Sealer No. 12; Opex Enamel is applied over the old finish without surfacing. The car should be cleaned and prepared the same as in the two previous systems, taking special care that all grease, dirt and oil are removed.
Where the old varnish film is not crazed or cracked, and therefore does not require surfacing, we recommend a coat of Opex Clear Binder No. 67, which serves as a bond coat between the old varnish film and the new lacquer. Opex Clear Binder is an especially designed product to serve this purpose.
Spray one very light dust or mist coat of Opex Enamel. reduced with equal parts of Opex Thinner No. 2. A heavy coat will probably raise the old finish. A dust coat if applied properly will never affect the old finish.
Apply two or three additional but heavier coats of Opex Enamel thinned with Opex Thinner No. 2 and bring up the finish the same as in methods previously described.