Oh, Lord, here we go again. Another round on paint mixing when most of us
have long ago accepted the fact that with all the changes in the paint and
chemical industries over the past fifty years we don't really stand much
chance of perfectly matching any prototype paint color. If we did, so what.
By the time we got a model painted with the "perfect match" paint onto the
pike to operate it wouldn't match anyway because the lighting would have a
different balance to it. And I sit here typing this in the heart of SPF
country (obviously not at home!) hoping this thread dies a normal death
before I get hit with a pail of someone's idea of a "perfect match" for Pond
Bottom Brindle....more commonly called Brunswick Green in this locale! (-:
Don Valentine
Quoting Bruce Smith <smithbf@...>:
toggle quoted message
Show quoted text
I said:
Now, since they had the same amount of pigment, you might assume
that
they were identical colors, but it turns out that you would be
wrong...for carriers contribute to color, and these formulations
might
have slightly differing hues due to that.
Garrett responded:
Errrrrrrgghhh, I beg to differ from my own experience within the paint
industry.
The goal with this and with color matching is to ensure that not
only dry, but dry the same color. They dry them on cards under
controlled
lighting for comparison. There should be no tint from your solvents, or
none that you notice between mixes. Compensation needs to be made if the
solvents do influence color once dry. Did I say ANYTHING about color matching <G>? Nope, not a word, and
neither do the PRR specs. They took X lbs of color paste (spec #
so-and-so) and mix it with Y+Z gallons of solvents. These were
instructions to the troops, not something from "the paint industry".
As was pointed out to us at our meeting, paint matching at the end of
PRR was done by the shop foreman opening a 50 gallon drum of paint and
slapping some on the shed wall (CONTROLLED LIGHTING???). He would then
take a little bit of this and a dash of that and paint the
car/loco/etc...no second swatch there!
Counterpoint (and in defense of what you are saying) the weathering
rates
from changing solvent amounts are different afterwards <snip>
Shelf life (remember when I caught you guys coming out of the elevator down
in Cincy?) can be a factor with solvents and filler (cellulose) as
they age. Absolutely, and our conclusion was that you cannot use old liquid paint
samples to get accurate colors by painting mixing them up (there are
other ways...).
Finally, the PRRT&HS paint committee's charge is to help
manufacturers,
modelers, and restorers to (as accurately possible) match specific
PRR
colors. At our first meeting, we decided that it was a daunting
task,
and that we would somehow succeed in at least defining baselines to
work from...we'll see <G> Just as long as you all know that you will need a different mix for
each of
the above, and each scale. What looks good on a 1:1 restored N5c will
be
wrong on an HO N5c, and what is good on the HO N5c will look wrong on the G
and N scale ones. Indeed, and another issue is the weathering of restored equipment...it
isn't any good if that museum car is pink in 5 years (unless we're
talking...)
Ah, but then there was the weathering mentioned above......so throw
all of
that out and do your own mixing at the air gun with the naked model on the
bench. Um, I think I said "defining baselines"... I think we realized
immediately that we'd be nuts to deal with weathered paint...but what
you need to accurately weather is a starting point. The question, for
historic railroad colors, is how you get there since many of the
assumed starting points are of dubious value...
1) Color photos - nearly useless
2) Drift cards - nearly useless (heck they are 50 YEARS old...they've
oxidized)
3) Liquid paint samples - nearly useless (oxidized, broken down)
4) paint chips - nearly usesless (weathered, even if painted over)
5) memory - sheesh! I can't remember what my wife was wearing this
morning...and you're going to TRUST me to tell you what 2004 CSX blue
looked like, FIFTY years from now??? (not to mention, I'm not usually
seeing the "baseline" but a weathered derivative.
Now before you conclude that all is hopeless, there is a glimmer of
light (although the oncoming headlight analogy may be very
appropriate). By focusing on the CHEMISTRY of these paints, the
ingredients that were used and the time frames when these changed, we
may in fact generate good ranges of paint color that accurately depict
appropriate archival paints...its going to take some work, and a
realization that there is no "perfect match" because there was no
unique one single color, but a range of colors very close to a
target...Which just reinforces what some folks have been saying for
years...your cars should not be all exactly the same color (but at
least they should be in the ball park, eh Bowser?)!!!
Time for a Beer!
Happy Rails
Bruce
Bruce F. Smith V.M.D., Ph.D.
Scott-Ritchey Research Center
334-844-5587, 334-844-5850 (fax)
http://www.vetmed.auburn.edu/~smithbf/
"Beer is proof that God loves us and wants us to be happy" - Benjamin
Franklin
__
/ \
__<+--+>________________\__/___ ________________________________
|- ______/ O O \_______ -| | __ __ __ __ __ __ __ __ |
| / 4999 PENNSYLVANIA 4999 \ | ||__||__||__||__||__||__||__||__||
|/_____________________________\|_|________________________________|
| O--O \0 0 0 0/ O--O | 0-0-0 0-0-0
------------------------ Yahoo! Groups Sponsor
Yahoo! Groups Links
|
