Brief History of Corvette Paint. 1953
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1. Corvette Paint Restoration and Judging NCRS Guidelines to
Typical Corvette Factory Paint Finish and Body preparation
2. Brief History of Corvette Paint 1953 – 1957: Nitro-saleous Lacquer Paint
1955: Start of the use of Metallic paint
1958+: Acrylic Lacquer Paint
1985+: Clearcoat Paint process
C5’s: Waterborn Paint
3. Typical Lacquer Paint Finish Small, tight-patterned orange peel appearance before buffing, due to high solvent, low solid nature of lacquer
Normally buffed with very coarse compound to level finish and improve gloss level (OEM applications)
Darker colors were buffed more than the lighter colors, due to ‘showing’ more orange peel
4. Typical Lacquer Paint Finish Areas not buffed normally exhibit low gloss level, and small-patterned orange peel
Side vents on mid-years, bottom areas of body and doors, door jams
Less paint applied in number of areas, such as: bottom of body and doors, radiator support, door jams, etc..
Metallics – striping or mottling is very common with lacquer paint
5. Key Paint Points Distinctiveness of Image (DOI) is one key focus of determining if paint appears as typical factory paint finish
‘Shininess’, or lack thereof, is not a factor in judging paint (Shiny is irrelevant)
Typical Dealer Preparation would have included a wax job with Blue Coral type wax, which would brighten (shiny) up the paint significantly
6. Orange Peel
7. 1963-1967: Exterior Paint Process According to GM Factory Bulletin Source: Chevrolet Engineering Center
Date: September, 1965
Primary Sanding – All body panels and bonded joints that received acrylic lacquer are dry sanded to prepare surfaces for painting. A filler material (called putty rub/lacquer glaze putty) is applied to the entire body to fill minor imperfections
Primer – Two coats of primer are applied (the first red, and the second gray) and are oven baked for 60 minutes at 280 degrees F.
8. Factory Photo: Body Sanding
9. 1963-1967: Exterior Paint Process According to GM Factory Bulletin Wet Sanding – The body is wet-sanded to provide a smooth surface for the sealers. Most of the gray primer coat is removed with the red primer acting as a depth signal for the sanding operation. The Body is dried to remove all moisture.
Note: The Factory used a power orbital/DA sander, which did not leave any straight sanding marks (something to look for when judging and be careful of when restoring)
Note: No ‘Gelcoat’ was used in original process (press molded fiberglass was used, and cars baked at 280 degrees)
Sealer – One coat of sealer and one coat of acrylic lacquer are applied and baked.
Notes: equivalent to a ‘thin’ layer of primer; Sealer sealed primer and and improved adhesion between primer and paint
10. Factory Photos: Wet Sanding
11. 1963-1967: Exterior Paint Process According to GM Factory Bulletin Dry Sanding – The body is dry sanded to prepare surfaces for the final acrylic lacquer
Lacquering – Three coats of acrylic lacquer are sprayed on the body to build up the required paint thickness. The paint is ‘rested’ for eight minutes to permit it to partially set up and to remove excess volatile paint vehicle (paint thinner).
12. Factory Photo: Paint booth
14. 1963-1967: Exterior Paint Process According to GM Factory Bulletin Initial Baking – The body is oven baked for 30 minutes at 140 degrees F, to harden the paint which permits the subsequent operation. Small interior and exterior parts are painted to complete the body paint schedule.
Final Baking – To assure a durable, hard, high luster finish, the lacquer is oven baked for 45 minutes at 250 degrees F. Reheating the lacquer permits the paint film to soften, and allows the surface blemishes and sanding scratches to disappear during the thermo-flow process.
15. 1963-1967: Exterior Paint Process According to GM Factory Bulletin Final Sanding and Polishing – The body is lightly oil sanded and polished to bring painted surfaces to a high luster finish.
Note: Factory Sanding was really ‘spot’ Sanding, as they did not go over the entire surface of the car
Note: DOI (Distinctiveness of Image) goes down the lower on the car you go. The focus of sanding an polishing was on the tops and sides of the Corvette
16. Factory Photo: Paint Polishing
17. Metallic Colors Metallic colors are formulated with a type of pigment and aluminum flake in the binder that allows light to penetrate the surface of cured paint film. This light penetration, reflecting off the aluminum flake and passing around pigment particles of varying density, produce the ultimate color shade.
The bars in the graphic represent aluminum flake and the specks represent pigment particles. Considering this fact, the following cross-sectional views of metallic paint film illustrate how varying shades of color may be produced from the same can of paint.
21. Metallic Paint Colors The actual size of the metallic flakes was much smaller in the 50’s and 60’s than they are in today’s metallic colors (appear almost ‘dust’ sized in typical factory finish)
However, there were some ‘coarse’ flake colors, like 1963 Sebring Silver – but still not coarse flake by today’s metallic standards
No two metallic cars of the same color look alike, even those painted from the same batch of paint, because of all the variables (painter spray technique, humidity, temperature, paint supplier differences, time between steps, etc…)
You cannot judge a metallic color against a standard paint chip (no such thing as standard)
There is an acceptable factory ‘range’ of shades and looks within all metallic colors
22. Paint Judging The purpose of NCRS Flight Judging is to determine how closely a vehicle appears to conform to the NCRS Judging Standard and to recognize such vehicles and their owners with NCRS awards, when earned, that generally reflect the current degree of preservation and/or restoration. In addition, the purpose shall include the judge’s transfer of knowledge to the owner on how that owner may further improve their car to more directly match this Standard.
23. Paint Judging “Cars are to be judged to the standard of vehicle appearance, and as equipped, at the time and point of final assembly by the Chevrolet Motor Division of General Motors Corporation. Presentation judging is to be in the condition normally associated with that of a Corvette which has undergone the then standard current Chevrolet Dealer New Car Preparation for delivery to the purchaser, exclusive of any dealer or purchaser inspired addition, deletion, or changes.”
24. Paint Color Judging Standard Deduction Guidelines Body Color Originality: 85
Note: there is no Condition scoring for Color
No Originality Deduction – Color corresponds to the factory installed body trim tag color code, if applicable. The shade and the metallic content and/or size, if applicable, is consistent with that applied by the factory.
Deduct 20% of Originality – Color corresponds to the factory installed body trim tag if applicable. However, the color shade is not consistent with the color shade applied by the factory.
25. Paint Color Judging Standard Deduction Guidelines Deduct 50% of Originality – Color corresponds to the factory installed body trim tag color code, if applicable. However metallic content and/or size, if applicable, is not consistent with the metallic size/content applied at the factory.
Deduct 100% of Originality – Color of side panel cove depression, hood stinger, and/or hardtop is a non-factory color, and unavailable factory color combination, or is applied in an inappropriate year of manufacture.
Deduct 100% of Originality – Color does not correspond to the factory installed body trim tag color code, if applicable, or is a non-factory color, or is a factory color applied in an in appropriate year of manufacture.
26. Paint Material/Application Judging Standard Deduction Guidelines Body Paint Originality: 45 Condition: 40
No Originality Deduction
Deduct 20% of Originality
Deduct 50% of Originality
Deduct 100% of Originality
These are documented in the NCRS Judging Reference Manual
>>See new Judging Flow Chart << to determine Standard Deduction
27. NCRS Paint Flowchart (This flowchart addresses Body Paint originality scoring)
28. Judging Guidance Paint Material Area
Judging does not care what the paint material actually is. Judging is only focused on what the appearance of the paint material is.
The determination of material shall be by appearance only. The practice of using polish or compound to produce evidence is not conclusive and may produce erroneous results. NCRS highly discourages this practice.
29. Judging Guidance Factory applied methods area
Refer to the appropriate NCRS Technical Information and Judging Guides for any specific info on factory application methods.
Evaluate the body paint for excessive orange peel and could possibly have overspray in areas are typical for that year of application.
Evaluate paint application in difficult-to-polish areas, which should not have as much “DOI” and luster as exterior top side areas
Non-Lacquer (Enamels or Urethanes) tend to build up on edges, valleys, and corners, giving the appearance of being dipped or excessively painted
The application of clear lacquer tends to create an unrealistic bright luster and depth to the body paint
“Shiny” is a different concept than “DOI” – DOI is an area that Judging looks for, Shininess is not.
30. Judging Guidance See Section #3, part 9 of the Judging Reference Manual which defines the proper “Originality Scoring” method
Corvette Paint is Judged with this method in mind as well
Successful Judging does not mean that you determine if the paint is actually that which was applied by the Factory. Successful Judging means that you have determined if the Paint appears or does not appear that it could have been
Generally, a component part judged to appear as a complete original item will receive full originality scoring credit, regardless of condition