If you have Sal Ammoniac (Ammonium Chloride),,about the simplest browning soln there is can be made with it.
2% (by weight) soln of sal ammoniac and water.
Use distilled water.
You don't need to make up much of it. Applied in the same way as most any rust brown or blue soln,, minumum amt on a small cloth patch. Just enough to dampen the metal surface. A little goes a long way.
Don't heat it up, just mix it up. It'll dissolve nicely at room temp.
Parts must be absolutely clean and clear of oil, grease and fingerprints.
It's not the fastest rust maker around,,but it's a sure rusting agent.
A Damp Box or natural heat&humidity from 'Ma Nature will quicken the process like most others.
Leave the jar of the stuff open and in your shop and everything around it in unprotected raw steel will be evenly coated with a nice red rust as well.
Boil the rusted parts and get a nice rust blue too.
