I have just had my grill chromed and I Have a few questions concerning the painting of the rough Chrome on the vertical and horizontal bars of this grill.
Are the three vertical posts painted or are they left with that rough chrome look?
Since paint does not adhere well to Chrome, what preparation is done to the rough Chrome on the horizontal bars?
Is there a particular primer and finish paint that,if used,will last?
Someone else will have to speak to the '40 L specs, but when I paint a grille/trim that has black out of the fins, I just clean/dewax with standard prep solvent (50 -50 VM&P and Thinner). Mask it off, then shoot with a flat black trim paint. I've been doing it for decades. Not that difficult.
See attached picture of grill on an original 40-5019 seen at the Kansas City GN a few years ago. This is on a very original car. The picture can be zoomed to see better. As you can see the only chrome showing is the outer face of the ribs. At the sides there is some chrome showing but you can also see black in spots so my opinion is it was all black. The black is quite flat or satin. Really hard to tell for sure on the flatness. I have done two 40 Cadillac's which are done in a similar fashion and made it satin. This is on the main center grille. The side grilles on the Cadillac are body color. Doing this is nothing but hours since most likely have many pits to fill. Something that Cadillac didn't have to deal with when new. Start by masking off all the chrome that will be chrome. Use razor blades to made the edges on at least one edge of the tape. Use many blades so they stay sharp. Lightly sand and/or use red 3M pads on all of the chrome to be painted. Use PPG Epoxy DP90 (black) non sanding primer for two coats. Then use a sanding primer surfacer to fill the pits and flaws. Sand using blocks of whatever will work and get your fingers sore. When complete remove all tape and smooth out the paint edges with rubbing compound or whatever is needed which doesn't scratch the chrome. Retape for painting. Do a final coat of DP90 again to ensure adhesion of the paint since you will have rub through's with bare chrome in spots. The DP90 actually has a semi-gloss finish that would be very correct but it is not UV durable so does need a top coat of your favorite paint. I use a black epoxy primer surfacer (not urethane) and semi-gloss lacquer for the finish coat so all black products are used. On my 40-60S this system has survived 19,000 miles and 10 years plus with just a couple of chips so it does work. I am doing a 40 LaSalle grille right now. Not as much work as the Cadillac grille but still not a lot of fun.
thanks guys. Much appreciated.
Wonder how they did this process in the factory? because there's no way they had men going through the process that we have to do now as Bill has described. Immersed in paint perhaps with some mechanical way of wiping the paint off the chrome face??
In another thread about painting emblems it seems they used a sheet metal masking jig. I assume they also used that in other places also. They would have several and clean them often.
I doubt they were immersed because then the back side and everywhere would be colored.
I wouldn't be surprised, in the early days, with lower production, they just had skilled painters hand paint the accent.
The '60s aluminum grilles and tail light bezels that were blacked out were obviously sprayed and flat paint. I don't recall seeing masking edge lines. That's when I started touching up during detailing.