[alfa] Paint

["John Hertzman" <johnhertzman@xxxxxxxxxxxxx>]

Jon Durham asks "Where can I find the original Alfa paint 119? I have had several occasions when the paint was not properly mixed", and Biba replies with suggestions that he take a piece of the car in and have the paint shop combine yellow ("a very elusive color") with "a bit of blue" and compare the results in noonday open shade outside. "If it looks fine, they've done their job."
 
'Scuse me, but while at the consumer level color may not seem like rocket science, at the laboratory level it isn't magic. To a paint chemist pigments and dyes are reproducible substances, and quantities are measurable; AR119 is a specific mix of particular quantities of particular pigments (and/or dyes) in a particular vehicle. Alfa's paint supplier (usually but not always PPG, which is Ditzler in the USA) will have a different code number for every production mix formula (Ditzler 82112 for AR 119), allowing an exact match. Competing paint manufacturers will have their own codes (example, DuPont's 44344 for AR 119) but most if not all have cross-references to Ditzler numbers and from Ditzler numbers back to their own products, whether Sikkens, Glassurit, Rinshed-Mason, House of Kolor or whatever. Any two or more of them should be able to produce perfect matches for each other's paints regardless of ambient light source, time-of-day, season, or latitude. The result should be as particular and finite as, say, valve clearances set with micrometers and feeler gauges. You shouldn't need to set valves with a smidgin of clearance on the intakes, a tad more on the exhaust, and then check that they sounds about right.
 
One caveat is that some pigments (more in the past than in the present) may fade or otherwise degrade; another caveat is that low-bid body shops may have done "good enough" repair jobs by eyeballing approximations by mixing leftover paints from prior jobs. Those are different questions. Sikkens (Akzo Nobel Coatings) has a great system for matching such color problems; they have a "color grid", a loose-leaf book of large color-swatches with a hole in the middle of each swatch, so the "close" sheets can be taken to the car (in Biba's open-shade midday daylight) and the color on the car can be viewed through successive color fields until the desired match is found. Then it is back to mixing exact quantities of known materials. Very useful if you want to get a perfect match for a nonstock color. If you just want to get the exact color your canary Spider had in 1972, all you need is the numbers; 82112 for any reputable paint store that can mix to a formula identified by a Ditzler code. 

There are people whose opinion differs, just as there are those who don't need no torque wrench to tell when a nut is tight enuf. They are welcome to their opinion. They may be great mechanics, great painters. There are, admittedly, arts, fields where subjective judgment outweighs more mundane humdrum facts, and I do admire the artist. Jon's question, "Where can I find the original Alfa paint 119?" tilts to the specs, not to the art.
 
Cheers
 
John H.
--
to be removed from alfa, see /bin/digest-subs.cgi
or email "unsubscribe alfa" to majordomo@domain.elided