Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

In the course of trying to properly restore some of the early German engines, I have come across several that have damaged blueing on the boiler or the blue has been polished away altogether(and even once by me).
I didnt like the results I was getting with commercially available blue solutions, which most seemed to be more black or brown. I am after that rich, violet blue color on a beautiful original condition Bing.

After many failed recipes, I finally hit close to the correct one. [ Guests cannot view attachments ]

Above shot in natural lighting. Below, under 40 W incandescent desk lamp. [ Guests cannot view attachments ]

Opinions? Not blue enough is my first reaction, but I look at some examples I have and I think it just needs 10 more minutes in the bath.

I like that, Benny!

Brass can be a little tricky.

Gil

Among the problems you may be experiencing is the actual composition of the brass itself, the method of creation, and the "temper" and surface
"case" that it may have, along with various levels of surface oxidation. The odds of your test pieces being the same as any old boiler you may be thinking of doing are rather remote. Still worth trying this wonderful experiment to its fullest, and as you say, if it doesn't produce the effect you are after, just polish it off and try again. Most boilers have large surface areas that are hidden in the firebox, so provide test areas that will be specific to that boiler, that will not show on the finished product ... good place to try looking for that just right color.

Very interesting Benny, and I hope you can figure out that "purple-blue" as it's a special color, unique to so many of our engines.