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

Hello Maurice,

I am interested in the Brunnier agent that is suitable for brass. I am rather cautious about the agents for steel products. Finally, the treatment with all Brunnier agents triggers an oxidation process on the metals.  This oxidation prevents or at least delays a further oxidation process (in steel or iron, for example, rust).  A protective film is applied to the material.

I spoke on the phone a few years ago with the employee of a company that sells the agent "Gun Blue". The agent is used in the bruising of guns, that is, for a steel product. I wanted to know if the agent is also suitable for non-ferrous metals. He answered in the negative. You can understand that this made me a bit cautious. Perhaps the agent attacks non-ferrous metals too strongly for steel products.

I would appreciate it if there is a member in the forum who can make concrete statements on this.

I have another small tip. My wife put me on it years ago. She regularly cleans steel and brass fittings in the kitchen and bathroom with a paste called "lemon balm". Is also suitable for silver. I clean my brass boilers, which, when I get an old steam engine, are often very dirty with gummy oil or other substances usually in a citric acid bath (8 g citric acid to 1 liter of heated water). The citric acid dissolves quite incidentally any lime deposited in the boiler excellent. Any impurities still on the outside of the kettle after the bath are polished off with "lemon balm". Always works. Unfortunately, an existing bruenning is also removed together with the dirt.

Lemon balsam has the property that when a bright brass kettle is polished with it, a protective film is put on the brass at the same time. If a kettle is to be bruised after treatment with the agent, it must first be rubbed with citric acid or vinegar. Otherwise, the bruising agent will have no effect.

Under the attached link you can purchase "lemon balm" from Jemako.
Jemako is a Dutch company that, as far as I know, also sells outside Europe. The link is from German ebay.


https://www.ebay.de/itm/153901944282?chn=ps&norover=1&mkevt=1&mkrid=7071533165376683&mkcid=2&itemid=153901944282&targetid=4582627049753642&device=c&mktype=&googleloc=&poi=&campaignid=376712746&mkgroupid=1264439088661572&rlsatarget=pla-4582627049753642&abcId=9300540&merchantid=87778&msclkid=3b468b5a3f6b1dd7a351ebe47c95e0d8

Stay healthy