I have a friend in the Netherlands who is finishing a DJH brass Garratt loco. He needs to paint it and was wondering how to paint the chassis etc. I have suggested Hobby Black if it is available near him but does anyone else here have a few suggestions for painting mainly the frame around the Nickel Silver Valve gear?
I have no actual experience of Hobby Black myself but have dealt with chemical blackening of copper and brass, more years ago than I care to remember.
No experience with the chemical, but I do have a word of warning: most paints and other volatile liquids can’t be shipped by air, and many places won’t ship surface internationally. Keep that in mind when recommending solutions.
Hobby Black or A-West’s Blacken-It both work well to give a tough blackened finish to most metal parts. It’s important that all parts be free of oxidation, though, both to get good coverage and to economise on blackening agent. Steel wool can be useful for removing oxidation from brass or Zamac parts, although you must ensure that all steel wool residue is removed - it will react with the blackener, but not with the same results. Small parts can be immersed (use a small, non-metal container), but don’t put the used blackener back into the original container, as it will contaminate the unused material. I like to use plastic film containers to store the used liquid - it will still have some blackening power in most cases, and when it weakens further, I use it to weather scrap metal bits and pieces to create scrap loads for gondolas. For large parts, like frames, boilers, tenders, etc., apply the blackener with a brush.
Follow the directions that come with the blackener, both with regards to safety and procedures.
Here are a couple of older photos of cast Zamac locos done with Hobby Black. Only the boilers, frames, and cylinder castings, plus any brass details, were done with blackener. All plastic parts, including cabs and tenders, were painted.
An MDC Ten Wheeler:
A Tyco/Mantua Mikado:
And a John English 0-4-0:
Here are some scrap loads done, all or mostly, with blackener. These are Athearn flatcar stakes, done with only blackener:
