Trying to match passenger car paint.

RaritanRiverRailroadFan4 posted:

Any tips on how I can match the paint for the other 3?

I had the same issue years ago, when I found a Baby Madison heavyweight dining car on ebay that was a different shade of brown than the other seven passenger cars I had.   My approach was to pull out my Tamiya acrylic paint collection and then do a process of mixing until I got a match.   I've gotten good at that over time, using these guidelines:

• a mixing station should include spray gun bottles  and any type of scap hard plastic (which is what you will put your samples on). 
• You then start mixing, using a base color that is approximately that of what are trying to match.   Remember that acrylics get darker as they dry, so take that into account while mixing.
• In addition to matching color, you are also matching reflectivity (how much sheen is in the dried finish).   Since it's easier to start mixing  with glossy paints and dull then as necessary  than to take dull paints and make them glossy, my paint arsenal is generally glossy (with an ample supply of flat black and white). The latter can be adjusted to the right level of sheen using clear flat base or small doses of flat Modge Podge.  In my experience, most finishes on factory made engines or rolling stock are in the "somewhat satin" range.
• You then through trial and error start putting a sample of your mix on the scrap plastic, just a small dab will suffice.   You then let it dry for at least an hour and then in good light hold the scrap up to the surface you are trying to match.  Inevitably your first few tries will require adjustments , but as the process goes on you will soon begin to see you are getting close. 
• Often, dead on matching requires adding certain complimentary colors.  I recently wanted  the ends of a Williams boxcar I had to match the sides (in stock form, the ends were silver which matched the roof).   The stock sides were a Kelly green, which I was having trouble matching until I started adding a deeper shade of blue to the yellow-greenish mix I started with.    After about five minutes of tweaking, I let it dry and when I returned was pleased to find I had a dead on match.   Unscrewed the boxcar from the chassis, masked off the roof and then sprayed the ends (ended up painting the roof brown).   Here's the result:

RaritanRiverRailroadFan4 posted:

A few years ago a 7 car set of CNJ passenger cars were painted and decaled in a certain shade of green. My issue is that I found 4 more of the same cars and one of the cars happens to be already painted in that same shade of green while the other 3 are in a primer grey. 

Any tips on how I can match the paint for the other 3?

Take a car already painted in the color you want and to an automotive paint store.  Not a parts store that sells paint on the side, but a dedicated auto paint store.  They can match your color so well you can't tell the difference.  They will have a color matching machine that is spot on.  And they can sell you whatever type of paint you want to use, acrylic, lacquer, etc.  They will even be able to fix you up with a rattle can of your color for around $18 (that's what I pay here).   They can adjust gloss and dry time.  I've done this for all kinds of projects, sometimes even cars...

Waddy posted:

RaritanRiverRailroadFan4 posted:

A few years ago a 7 car set of CNJ passenger cars were painted and decaled in a certain shade of green. My issue is that I found 4 more of the same cars and one of the cars happens to be already painted in that same shade of green while the other 3 are in a primer grey. 

Any tips on how I can match the paint for the other 3?

Take a car already painted in the color you want and to an automotive paint store.  Not a parts store that sells paint on the side, but a dedicated auto paint store.  They can match your color so well you can't tell the difference.  They will have a color matching machine that is spot on.  And they can sell you whatever type of paint you want to use, acrylic, lacquer, etc.  They will even be able to fix you up with a rattle can of your color for around $18 (that's what I pay here).   They can adjust gloss and dry time.  I've done this for all kinds of projects, sometimes even cars...

You beat me to it but that was going to be my suggestion. Easiest way.