Many may know this but for others. I've heard of this but never tried until the other day. Soaking new shiny bolts in household vinegar,
it takes about a week but it it worked.
Bob
True.
Quicker: media blast, paint with BBQ black, bang around.
But vinegar is the key to authentic looking brass. Add some salt and it will blow your head away.
I use Blue Lightning rust remover because I happen to have some for derusting small parts. It works overnight. But if I were buying something just to unfinish new hardware, I'd go with the vinegar and take a week, because it's a lot cheaper.
Even faster is PCB Etchant Solution (Ferric Chloride) available at Radio Shack, works in seconds.
Howard Dennis
Muriatic acid takes about 10 seconds but it's mean and nasty.
It is highly corrosive and emits poisonous fumes
Evapo-rust removes zinc plating from galvanized metal and is safe to use. It can take anywhere from 30 minutes to a few hours. According to Caswell Plating's website, it will also remove cadmium plating.
I haven't tried it on galvanized bolts but I did use Evapo-rust to remove the plating from some galvanized shelf brackets.
My experience is that Evapo-rust will not harm chrome plating which agrees with the information listed on Evapo-rust's website below:
"How Evapo-rust affects coatings
EVAPO-RUST is highly recommended by the NRA gunsmithing school and is utilized by FBI, CIA, NATO and other law enforcement and forensics agencies. EVAPO-RUST is perfect for removing oxide weapon finishes such as Bluing, Parkerizing, Zinc Phosphate, and Browning.
Anodizing, Cobalt Tungsten Carbide, Powder Coating, Chrome, Nickel, Paint, and most other coatings will not be removed as long as they do not contain oxides. EVAPO-RUST will not harm lead or solder points."
My choice is Phosphoric acid. Fast , inexpensive and wont rust afterward.
Wire wheel. Flat Black enamel.
If you have good oil nasty used motor oil you can heat them up and drop them in...they'll turn black
Since this thread is about converting new bolts to old look, mention should be made regarding the removal of the grade marks on modern bolts. One can easily grind off the raised grading marks on top of the bolt with a dremel tool and smooth with sandpaper and a buffer before applying the acid treatment and patina process. Making a new bolt look old without removing the modern markings and smoothing the top defeats the whole purpose. Jim Patrick
I soak new bolts and screws in hot cider vinegar for a few minutes to remove the plating, then heat them with either a propane torch or in the oven if I'm doing a bunch and dip them in "Plum Brown Barrel Finish" for gun barrels- instant age and rust. A little black shoe polish finishes the job.
Jim, Disk sander works well,too!