Which I'm sure DuPont's were, but that only prevents fading. There is some concern that the varnish vehicle will continue to oxidize over time, and turn darker. How valid this concern might be is anyone's guess.

We recently ran into a problem, specifying UP Armor Yellow, in the current iteration of Imron. My predecessor assumed that if he specified a UP specific color that they could mix to that specification...

Of course the paint has been shifting in color and formula for some years, most significantly when lead was removed from the mix... which makes the current yellow more transparent... Which changes the color...

Of course, the auto paint supplier did not have the railroad paint codes, so was trying to match to a color that they only "kind of" understood. Ultimaly we had the comercial rep involved, who also couldn't access the railroad paint codes but came with books and samples and we have been much more successful.

Our project was also complicated because the previous team thought that clear coating was superior... The clear coats are in part there to give a "special" gloss, not found on railroad equipment... but "it is better".... and of course in the desert the clear coat fails early and can't be buffed out...

Paint codes are only true for a short period of time, when "That" railroad was ordering paint for "that" project in "that" specific paint... As the new guy at first I let the existing plan go forward, but as it hasn't worked have had to get more involved...

I do use PMS when documenting paint for historic reports. I have used Munsel... but a PMS book is $100-$200 while a Munsel book is on the high side of $1,000, and while Munsel might be the better system, PMS is more available. I have in some cases made drift panels on stable artist board with acrylic paints (stored in dark places) to match colors not covered by Munsel or PMS... The key is to document, and describe what you found and how you have documented it...

The whole paint thing is a problem because we don't have the original materials available, so are chasing the colors and technology... and making up solutions... I have long threatened to paint something in shades of grey... (aka gray)

Randy

I enjoyed Eric Hopp's restoration web page, but there are no updates since 2013. Anyone know the current status of the 1146?

Eric went and got himself a wife, so that pretty much put the 1146 project on the back burner for the foreseeable future.

That will do it....

It gets easier once to grok that the "official" color was a theoretical academic construct and was only around in reality - if at all - for a brief interval on only some (if any) of the rolling stock it was specified to cover since paint was not mixed to a high standard of accuracy in bulk for industrial use and once applied it faded, weathered, and was stained by pollutants surrounding it. there's nothing indefensible about doing the best work you can on finding a paint that closely approximates your perception of what the documentation tells you it should have looked like theoretically based on what you can find out from historic sources. You're very likely going to be within the kind of tolerances that the original painters were as well. I have a color chart of available mixtures available in modern paints which I try to match to what I have for evidence - sometimes by going through layers - and generally I can come very close, and perhaps have the tinting altered slightly to get even closer. At some point you have to stop overthinking and know you've done all you reasonably can and get the damn job done.

I'll second Dave's comment. Something I learned to keep in mind when trying to match historic colors: The exact color of the original paint varied from batch to batch whether you were buying the dry pigment and mixing it in the shop back in the day or buying batches of premixed. The same color varied between manufacturers. The drift card colors were the target you were hoping to get close to. The same is true today with computer-based scanning and mixing. You may get real close but maybe not exact even if using the same chemical formulation. Hence the recommendation that you buy a bit more than you need so you don't have paint from multiple batches on a smaller project or you mix from the different batches before painting a large project. The final color also depends on the application of the paint to the surface. Lighting angle makes a big difference in the perceived color. As soon as the paint is exposed to UV, it starts to deteriorate. Way too many variables to tear your hair out over. Apply the 20' (or farther) rule and you'll be good to go.

Spraying polyurethane coatings can be a serious health hazard. I wouldn't dare paint with Imron or equivalent myself. I'd leave that to the professionals with full suits, positive pressure and filtration spray booths.

Just my two cents...

Eric