Quote:
Originally Posted by Kevin in NJ
I learned about this from Marco. I observed this on my car.
I used Concept single stage paint. I am not the best painter so I had to color sand. The areas where I laid down great paint the depth and shine were out of this world.
Paint that is able to form a liquid surface will be virtually void of scratches. As soon as you do a buffing process you are essentially sanding with very fine sandpaper causing scratch. It is subtle, but there.
I do not have the correct numbers handy, but the laquer of the 1930's was not very 'pure' and had about 80% reflectivity.
The modern stuff sprayed well is in the mid 90's and buffed it gets down to like 90%.
Again I made up the numbers, but that is the idea.
Marco flattened the paint on areas like the firewall and door jambs. It buffed out the exterior just to lower the reflectivity to do his best to get and original patina. He was clear that it still was much glossier then some of the original untouched cars he has inspected.
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Again, there is some confusion in this. The reason why many aged lacquer paints do not have the sheen is because the oils have evaporated over time and caused the paint to 'dry out'. They were much glossier back in the day, and this can be proven by comparing freshly sprayed Pyroxilyn or Nitrocellulose lacquer paints.
Regarding Marco's technique, there for awhile the trend many of us trying to restore to an authentic look was to add the 4985 flattening agent trying to mimic the 'unbuffed' nitrocellulose lacquer look of jambs and under-body areas. The problem was it would tone the sheen down however it wasn't replicating the look of the lacquer. Terry Deters (-who often is the Area 14 Team Captain at MARC meets) and I discussed this at length one time when I was trying to authentically (-at least aesthetically) paint a 76A pick-up. I wound up spraying some old Ditzler lacquer in the two-step process as described in the Paint & Refinish Guide to see what I needed to do to replicate it using PPG's DCC line. As Kevin is saying, the depth of the paint is not close to Nitrocellulose lacquer however I don't think it has to do with the pigment quality per se', but with the micro-scratches in the paint that refract the light. Even with flattening agent added, the texture was different even after colorsanding and buffing between urethane and the lacquer. The closest I was able to replicate it was to spray enough DCC urethane to achieve complete coverage and then allow to flash dry. Then using a hot lacquer thinner in lieu of any DT*** solvent, I used a hot Lacquer thinner to catalyzed DCC paint and fogged one medium coat within the re-coat window. Because that paint was not going to be colorsanded nor buffed, the lacquer thinner for a solvent caused it to take on the sheen and texture much like freshly sprayed Nitrocellulose lacquer paint.
One final thought when trying to replicate the original texture and sheen, the paint was actually colorsanded originally using a coarse paper (-something like 220 grit) with the intent of only knocking out any runs, dry areas or blushing. Then a solvent (-likely a lacquer thinner with lots of retarder added) was sprayed onto the dry paint and it softened the topcoat allowing the paint to soften and flow into some of the scratch marks. From there is was allowed to dry (-which happened quickly) and then buffed. Likely the heat induced from the wool pad also allowed the paint to soften and reflow. For those of us who have used lacquers on custom show vehicles in the past, we know that we can achieve very deep sheen using lacquer toners and clears.