From: Doc Bryant (rbhonk1@cox.net)
Date: Mon Mar 01 2004 - 00:05:19 PST
It's late and I should be at work, but let me address Jim Gilmore's reply to
my tongue firmly welded into cheek post of recent...
I eventually tossed all my microfiches of the paint formulas. Hie ye to
your local Sherwin Williams authorised dealer or factory store and flash
those numbers to them. They ought to be able to fix you up in a jiffy.
Also the folks from PPG Ditzler have a pretty extensive "antique" vehicle
color library. I was envious of their database when I was in the business.
All the manufacturers use a highly regulated standard of preparation and
application. It does not mean it gets followed. The product they used as
OE is different than the product applied in the aftermarket. We don't use
the "turbo bell" applicators that use all sorts of high tech whizz bang
things to apply paint which is then high heat baked. If the lines are not
cleaned properly when doing a color change, there darn sure will be
variations. If there were not these deviations from the Handed Down From
God specs, paint reps would not have alternate color match formulations when
they went to visit body shops.
Thinner/reducer changes...
Oops I ran out of the right stuff, this ought to work.
Again, the guy in the booth does something out of sight of the shop manager
inforcing the rules. He is smart enough to know how to blend across a
panel. He hides his secret rocket science chemistry work. No one knows the
difference until the paint fails. Oops, sorry lady, your warranty expired.
Yes we have an out of sight warranty. When your car is out of sight, its
out of warranty. Next victim please...
For example, many people in my territory would use S-W's Polasol or Polasol
Plus Acryld Enamel hardener in DuPont's Centari or PPG's Delstar. The same
thing with S-W Enamel reducers. I sold more of those than I sold
corresponding quantities of color. Why? Rocket Science chemistry as we
called it. The Rocket Scientist who dabbled as a painter found out that our
hardeners and reducers slowed the dry time of the other folks products,
allowing longer flash off times and less die back due to solvent entrapment.
Oh damn those detailed application instructions. At the time I was in the
business, 99 out of 100 body shop managers did not give a rats rear end what
happened in the paint booth as long as the job rolled out the door and did
not come back. We reps saw it as a nightmare waiting to happen. But we
knew we could deny any warranty help if we caught the Rocket Scientist in
action. And secretly, all of us enjoyed the sales commisisions when a place
that did not buy our color did indeed buy some of our other products. Oh
the shame of it all!
Synthetic enamels are air pressure and reduction sensitive. That changes
dry time, which can change color. Look at a repair job under different
lighting, parking lot lights, daylight, shade et cet. Having said that, the
last time I shot synthetic enamel was one of the competitions brand
(Sikkens) to repare a Ferrari that got keyed. We blended the repair as the
factory supplied paint (red) was not a panel to panel (exact) color match to
what was on the Ferrari.
GM had a bit of trouble applying paint in their plants, as did the other
manufacturers, even Ford, which sold their own paint line to DuPont eons
ago.
We sold paint initially to the repair shops based on the GM specification,
and our approved match to that specification. We saw trouble when we were
told our product did not match the cars. So, research found the variations
in color as applied at the factory not to their approved standard. How we
researched this was we returned car parts that were painted to that color
code to our color lab for them to compare to their approved sample panels.
Then the color lab issued variation formula so we could match what we found.
My whole thrust of my post was to say that yes, there are standards, but
sometimes the standard might not be as standard as you think.
I noted in the posts of others who own Military Vehicles that there seemed
to be some issue of what color was what, and what was applied, standards
pertaining too...and all that Mil Spec Speak.
My reply was in a nut shell, if it got repainted somewhere, maybe at Camp
Swampy, Painter Beetle Bailey did not do what he was told, he did what he
found out worked. Do remember the phrase, "Close enough for Government
Work."
I suppose if we were talking about Grey paint, we could wonder what Gruber
and the rest of the gang at McHale's Navy did.... ;-)
And sorry, but I have to disagree, the factory standards and procedures do
get violated at the factory. That's what made my job so interesting. And
since you and I were not in the paint booth, all we can see is the finished
product.
Let's move on....
Primer Surfacers and Primer Sealers. The sealer is supposed to seal off the
primer or the existing paint (if so authorized for overcoating, UH OH,
Standards....Sorry. I slipped). There are now barrier coat sealers such as
some of the European pioneered urethanes that can help prevent moisture
incursion from the top coat to the bare metal. The nitrocellulose primers
of WWII vintage were quite porous to water incursion. Also, they never
really became solvent insensitive. An epoxy or linked urethane is a
different matter. But not available then. If one were to use a urethane
primer sealer under the paint of choice, expect to see a surface gloss
difference due to the lack of solvent die back into the sealer barrier. Uh
Oh, we just screwed up the standards. Oh no.
Now, having noted that, when I finally paint my M37, its going to be a semi
gloss AF Blue, and it will have urethane paint and primers. Will it be an
exact replication of standards? Hell no, and I know it. Will I have to
repaint in two years due to the West Texas sun? Wheeeeeoooo. No. And for
that I will take a deviation from standards. Bring on the Firing and
Flaming Squad!
David Cole's ideas on moisture and system nature is pretty good. I will
leave it alone.
Remember, there is a solvent grip between paint coats (chemical) as there is
a mechanical bond made by sanding off the gloss.
Doc Bryant
standards, we don need no steenkin standards......
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