NorCam (Graeme Browne's) Lemans Blue 1969 Z/28

[cook_dw]

Good read for those that haven't seen it before. Nice work on the rear tub. What did you use to remove the black spray paint? I might suggest adding a heavy coat of Meguiar's #7 to hydrate the old painted surfaces.


CRG Paint Process Article by John Hinckley

"Fisher Body - Paint Shop Operations
The Paint Shop is broken down into phosphate, prime, sealing, and color departments; the body was suspended from an overhead conveyor with hooks at the firewall and at the ends of the rear frame rails through the phosphate system, and was transferred to a steel carrying truck before the prime system that carried it through the rest of the Paint Shop and through the Trim Shop.
Phosphate System: The raw body shell passed through a seven-stage phosphate system, where it went through a series of enclosed high-pressure hot spray stages where it was washed to remove all the oils and debris from stamping, welding, brazing, soldering, and grinding operations, then the body was coated with a hot iron phosphate solution which "etched" the metal and provided "teeth" for paint adhesion. The final stage was a de-ionized hot water rinse and blow-off, followed by a drying oven on the way to the prime booth.

Prime System: In the first prime booth, the entire body, inside and out, was manually sprayed with primer, and confined areas subject to corrosion were given a second coat of heavier primer material; this prime coat was then baked at 390F for 30 minutes. In the second prime booth, the instrument panel and rear of the shelf area (and the upper door and quarter areas of 1967-68 models) were painted interior color, and another coat of air-dry flash primer was sprayed from the belt line down. The interior color areas were masked, and the entire outer body was sprayed with gray primer-surfacer and the body was baked again at 285F for 45 minutes. The cowl vent panel was hung in the side window opening on wire hooks all the way through the paint process.

After baking, the entire outer surface was wet-sanded, wiped down, and the body went through a short infra-red dry-off oven on its way to the sealer deck.

Sealing: The primed and baked body passed through a long series of platforms where vinyl plastisol sealer was applied to all joints; floor pan drain hole plugs were installed and sealed, and the sealers were manually dressed in exposed areas. Floor pan deadener pads were then installed, which "melted" into place later in the color reflow oven. The body then went through a sealer oven to "set" the sealers on its way to the color booth.

Color System: The bodies were sequenced to "batch-paint" by color as much as the build schedule allowed, to minimize the waste of thinner required to clear paint guns between colors. The interior was masked off, the body exterior was tacked-off, and it then entered the main color booth, where it got three coats of acrylic lacquer, sprayed automatically with vertical and horizontal reciprocating spray guns, with a 3-minute "flash" between coats, followed by a 10-minute bake at 200F to "skin" the surface prior to sanding. In the next stage, any surface defects were power- and hand-wet-sanded with mineral spirits, then wiped off prior to entering the final "reflow" oven. This bake lasted 30 minutes at 275F, where the lacquer surface softened and "re-flowed" to a uniform gloss.

The last process for a non-stripe car was the blackout booth, where the firewall was blacked-out, the trunk was sprayed with spatter paint, and sound-deadening undercoat material was sprayed in the rear wheelhouses. The rear "cocktail shakers" on convertibles were suspended in the trunk for spatter painting, but weren't bolted in place until later in the Trim Shop, after the taillights and marker lights were installed.

If the car required Z28, Z10, or Z11 stripes or a black rear end panel or rockers, they were masked and manually sprayed in the in-line repair booth/oven system after the reflow oven, including the cowl vent panel; spoilers were painted body color separate from the body, and were final-installed to the deck lid just prior to the repair booth. The rear window filler panel, deck lid and spoiler were masked and sprayed stripe color in the repair booth, and baked in the repair oven before the body went back downstairs to the Trim Shop. The paint guns in the repair booth were fed from manifolds that were part of the main color circulating system so that the repair booth used exactly the same paint the main color booths were using.

If a unit required a major paint repair that couldn't be accommodated in the normal in-line cycle time, it could be diverted off the main line at the end of the repair booth into a parallel loop that ran in the opposite direction and fed the unit back into the main line ahead of the main repair booth; the re-run loop could accommodate about 20 units.

Paint System Information
The Fisher paint booth had pneumatically-driven overhead and side guns that reciprocated cross-car and up-down on trolleys, and were fed from manifolds on one side of the booth. Each booth had about 20 paint circulating systems fed from the main Paint Mix Room - usually 14-16 for standard colors and several others for thinner and one spare, and there were separate manifolds for hand-held manual spray guns used for interior and cut-ins. Every time that consecutive cars had different colors, all of those guns had to shoot thinner from the manifolds to the guns (through the floor grates) to clean out the previous color, then charge the line with the new color before they could spray again, and that had to take place in about four seconds.
Paint came from DuPont in 500-gallon tote tanks, with paint mixed from the same lot distributed to both the Fisher and Chevrolet paint shops to minimize color match and gloss issues between the body and the front sheet metal.

Special order paint colors were done by dragging 5-gallon pressurized paint pots through the booths and manually spraying everything; if there was a fleet or special order large enough, they charged one of the spare circulating systems, but that didn't happen very often - it didn't pay to charge a spare system for less than 100 cars."