Aging a Polished bright lock plate

Whats the best way to age a highly polished lock? Don't want to blue or brown and buff it back . Thinking just dulling the finish but don't know what would put a nice patina that will look good.
Any suggestions appreciated.

You might try vinegar or peroxide. I’ve always buffed back to what I wanted after using Jax black, Jax brown, or Brass black.

Yeah I was looking online and saw a lot old trade guns that were a dark patina and had some bare metal spots. Never tried peroxide on metal. Do you wipe it on?

I would think just wipe it on and let it sit. But as I said, it’s not a technique I use.

Degrease it with acetone before you do anything. You can use different substances, vinegar, mayonnaise, mustard, lemon juice. Experiment.
If you get a look you don't like a scotchbrite will take it right off.

I originally browned the lock and have buffed it back. Just not what I had in mind. The bright metal was too shiny. Maybe I should dull the metal first then add some patina?

Use it, and it will age on its own.

Mustard over-night …

If you must patinate the lock wipe it down with dirty (fouled) cleaning patches and let the filth sit on the metal for a bit. Do this each time you use the gun: it works a treat and gives an authentic used patina.

I've used mustard. It will dull it down and discolor it leaving you with a splotchy aged look.

I've used Duke's Mayonnaise, doesn't seem to be as harsh as mustard and might take several applications. Why use Duke's?, because it beats the heck out of Hellman's, has more of a lemony taste, which probably means it has more real lemon juice, and it is my favorite mayonnaise for sandwiches and burgers and I always have it on hand. I have also cut a Granny Smith's apple in half and rubbed it on the steel it will give you that medium gray to light black finish. You will have to just tinker around until you get a finish to your liking.

Phosphoric acid, sold as rust remover.

Degreases the lock plate with acetone.
Make it clear but not deep blue with Perma Blue or other stuff of that kind.
Clean it with some rubbing more or less pressed and more or less insistent with phosphoric acid, just like said Pete G.
The plate'll become gray and white (bit-like french gray), and polished no more.
Did it on a William Parker a few months ago...

This: Very versatile…works with both brass and steel(very light -dark grey, when applied to heated steel gives a worn color case(see lock in avatar photo)

Art Caputo said:

This: Very versatile…works with both brass and steel(very light -dark grey,

Click to expand...

Double post—-disregard

Vinegar will work in as little as 24 hrs but if you just wipe it on it takes much longer.
The acidic vapor is much better, soak a paper towel with vinegar and place it in the bottom of a quart mason jar, suspend the plate from a string, and put the lid on.

If you want it to look old and then cleaned, rust it then clean it. Any of the slow rust browns will work great. Jim Kibler used JAX. His work look awfully good to me. Beware of muriatic acid, it will rust and rust with no end in sight. I have no opinion on condiments. Bleach looks like a beach job, thankfully it has fallen out of favor.

Forgot to include this. "Buffed the lock" Hopefully that does not mean power buffing. A powered buffer with rouge has almost no place in any ML work. And when it does, it is with hard cloth wheels and purpose made abrasives like polish o ray. It take a long time to do a decent job. For the slight time savings is not worth the trouble. For 99% of us buffing gun parts does a terrible job and looks awful. Use only hand polishing with abrasive papers backed by files or contoured wood. Stones and diamond plates are good too. No free form sanding until you are at the #320 level. At that point I like to blend with maroon scothcbrite.

Cold blue and rubbing it back with 4-0 steel wool will gray it. It won't give you much in the way of rust protection though, so you'll have to keep an eye on it and keep it well oiled in storage.

I know you said you didn't want to do that for some reason, but it works. The blue will also go in to your engraving crevices and highlight it.

Naval Jelly (rust remover) will give it a dull grey finish.