Unfortunately matching old railroad paints is a loosing battle. Modern paints even with the same numbers are unlikely to weather in the same way as the old paints.

The formula for Pullman green is essentially chrome yellow plus carbon black. In some variations other pigments are included in fairly small amounts.

Chrome yellow is lead chromate. In addition to the lead it also includes soluble chromates that are another no-no.

Chrome green, another common pigment in the old days, is chrome yellow plus Prussian blue that contains cyanide compounds.

Vermillion, a commonly used red pigment, contains mercury.

Cadmium yellow and red contain cadmium.

All these pigments have the advantage of being cheap, fade resistant, and fairly stable in the weather. They all were widely used in railroad paints in the past.

The paint manufacturers have been forced to get the lead out. At the same time they have phased out many other pigments that are based on
other metals such as mercury, cadmium, and cobalt.

What the paint manufacturers have done is replace the original nasty pigments with organic pigments. You may get a perfect match when the paint is fresh, but the organic pigments are unlikely to weather the same way as the old metal based pigments. That's why some boxcar red cars have turned purple after sitting out in the sun for a while.

The only solution is to find the original paint formula and have it manufactured overseas if you
want paint that will weather to match existing.

I believe all of the pigments listed are still available in artist's oil paints if you need to cover scratch marks and other small blemishes.

fkrock@pacbell.net

Fred:
If the problem is the weather and probably more important UV damage is there not a good clearcoat that could delay weathering and still keep us out of EPA problems?

PS: the "old" paints faded also. "big four orange" faded to "indiana traction orange" and "danger yellow" faded to "ivory". and heaven knows what the varnish they used over the color coat went to. Does anyone paint "historically" any more ???

lamontdc@adelphia.net

> If the problem is the weather and probably
> more important UV damage is there not a good
> clearcoat that could delay weathering and
> still keep us out of EPA problems?

> PS: the "old" paints faded also.
> "big four orange" faded to
> "indiana traction orange" and
> "danger yellow" faded to
> "ivory". and heaven knows what the
> varnish they used over the color coat went
> to. Does anyone paint
> "historically" any more ???

The best over coat is to put the cars is inside storage buildings. Sure, this is not like the environment that they were once used in. But what we want to do is conserve and preserve the artifacts.

If we want to show the equipment in a railroad yard or run them in trains then we have to realize that the artifacts outside are going to need more paint, etc.

Brian Norden

bnorden49@earthlink.net

I am not aware of any clearcoat that will protect paint from long-term uv damage.The new organic pigments are not as stable as the old pigments.

In the very old days a paint job consisted of as many as seven layers. Two coats of primer were followed by three coats of color followed by two coats of varnish. That's where passenger cars got the name "varnish." All the coats were hand sanded before recoating.

One of these paint jobs would need to be repainted after about no more than two years. The process was very labor intensive, but labor was cheap in those days.

Synthetic enamels were introduced in the 1920's.
They lasted longer than the old paints and they required much less labor. They could be sprayed on. They were adopted almost universally.

I don't know of any museums that regularly use the old techniques. Few museums have the labor or money available to do paint jobs that need to be renewed every few years. They need paint jobs that will last. A modern paint such as Imron should be good for many years in a museum environment. I have seen claims that Imron will last thirty years.

fkrock@pacbell.net