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

Hello Maurice,

I have already written something on the subject in my thread "Another Doll & Co." at your suggestion. You are right, a separate post should be dedicated to the subject.

I have said in my above post that I use "Nerofor" from Ballistol for burnishing brass.

When I use "Nerofor" on brass, I get the following reaction: the coloration goes to brownish, but with a blue shimmer. The intensity of the coloration depends on the exposure time of the chemical to the material. After pretreating the material to be blued with citric acid to remove fingerprints and any oily residue, I coat the object with Nerofor until an even brown-black layer is formed. Then I leave the chemical on for varying lengths of time, depending on the degree of tinting I want to achieve. Then the object is washed off with clear water.

I have no idea what the blue tinting of the old steam engines looked like in the original. After all, that was 100 years ago. Meanwhile, after careful cleaning, all of my bronzed boilers have a brownish base tone with a blue sheen. I always try to preserve the original bluing. Damaged areas can be painted over perfectly with Nerofor, as described above. In any case, I have had only good experiences with the product. However, I have not tried any other agent.

I am not a chemist or metallurgist to be able to explain exactly how bronzing agents work. However, I suspect that the available agents do not differ much in their composition and mode of action.

However, looking at the boiler you showed, I think I can see that
the "blue stain effect" is somewhat stronger with Super Blue than with Nerofor. However, that may also be due to the time of exposure in each case. I would be interested in trying Super Blue.

Examples of my use of Nerofor can be found in this forum in the following thread:


https://www.officeofsteamforum.com/collections-pictures/doll-3441-in-new-splendor/

Hello Maurice,

There is a good reason why I paint my boilers with Nerofor. Nerofor is not cheap. 1 liter of the chemical costs about € 140.00. So you can imagine that I prefer to paint the boilers. This is a tedious business, but as you can see from my examples, with quite a respectable result.

It may or may not be of interest but i have a book here that has blueing and other colours recipes the book is from 1977 and has formulas and processes for just about anything you can think off measurements used are ounces and grains and quarts and some of the chemicals will require translating to common english 

Hello Maurice,

I have another question about "True Blue". Is this bruning agent suitable for non-ferrous metals? There are many bruning agents offered, but very few are suitable for non-ferrous metals. It is important to pay attention to this.

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

Very interesting thread. I have so far only used the blackening solution from Regner on brass, which turns it into a deep brownish black.

Of course. Here are some pictures of cylinders of an engine I have blackened with the Regner solution. Look at the last few pictures, with the cylinders before and after:
https://www.flickr.com/photos/28865130@N04/albums/72157622660772239

The process is easy, just place the cleaned parts into the solution (darkness varies with exposure time), then wash. However, a part of the dark surface oxide will go away with washing or handling the part, this is normal.

This is the chemical I have used: 
https://www.regner-dampftechnik.com/product-page/messingf%C3%A4rber-kaltbr%C3%BCnierer