Metal staines.

[Barryeye]

In my small collection I have an Italian dagger circa 1935 and a .22 rifle circa 1914. One thing they have in common is an apparent staining of the steel. No obvious rust pitting just these unsightly blotches. Any ideas as to how deep this staining might go and if possible the best way to remove it?

[SMOKEY]

I aint the smartest cookie on the counter but isnt that called patina

[dave]

The bolt, especially around the Pat. No., looks like rust, hard to tell from pics however. I have many bayos with similar stains and have tried Brillo Soap pads and it does not touch it. I just keep it lightly greased and forget it! I would not try any heavy polishing.

[Barryeye]

I guess you could be right Smokey but to me patina means a complete uniform change in the surface colour brought on by age. Not the erratic blotchy pattern as on this blade. I have bayonets from the 1870s that still have bright steel blades with just a hint of discolouration. I guess that materials used, maintenance and storage can produce odd surface patterns in time. I’ve tried the same things as you have Dave with the same results. I think I’ll leave as is.

[Johnny P]

Until the early 1930's most guns were blued by the rust blue process. A mixture containing nitric acid was brushed on the polished steel, put in a humidity cabinet, and allowed to rust. The rust was removed with either steel wool or soft wire wheels. When the rust was removed the metal underneath was blued. The process was repeated until the desired blue color was achieved.

On the two pieces shown, the only way you can remove the "stain" is to remove enough metal that it no longer shows. Just me, but I would leave them just like they are.