Re: #425 in Chrome Yellow . . .

D&RGW 223 Wrote:
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> Is it Chrome yellow or is it imitation gold (not
> metallic gold, but just a shade of yellow used
> to stand-in for gold leaf)?   I was under the
> impression that the locomotive lettering was
> imitation gold.
>
> In my humble opinion, it does not take getting
> used to, because I was hoping that it would be
> done in yellow from the get-go!   Thanks to all
> who put in the work to make it possible!


I wasn't expecting yellow lettering & numbers initially, but agree that all the recent research has paid off big time!

IMHO the various Railroad Companies probably used Gold Leaf very early on in their vain attempts to out-do one-another in terms of public support, credibility and fund-raising, and soon switched to yellow paint as it became more and more expensive to use gold leaf on fast-growing fleets of locomotives.  As a very-long-ago chemistry major, I am inclined to favor Chrome Yellow (lead chromate – PbCrO₄) as the primary pigment, especially as it tends to darken when exposed to air that's contaminated by sulfur compounds (a likely component of coal smoke) rather than fade as would most organic yellow pigments and the photos posted by Jeff Taylor appear to me show a darker discoloration rather than a fading on 225's tender.  Cadmium Yellow was also a fairly common pigment in that era, but was a brighter color than Chrome Yellow and also more expensive.  Look up both on WikiPœdia for further information.

- El Abuelo Histœrico, Greengo y Curmudgeoño de los Locomoturas Viejos y Verdes,
aka Der Grossväterlich DünkelOlivGrünDampfKesselMantelLiebHabender