Making Black Screws For a Muzzleloader

[oldracer]

In making my pistol (see the recent post) and redoing the 50 caliber Schuetzen muzzleloader I found I needed flat head or oval head wood screws. I found all the places in San Diego I checked had wood screws but were Philips head which doesn't look very good and not age appropriate at all. I found a place called Bolt Depot on the East Coast that had these and had either stainless or zinc plated with oval head slotted assortments. So I bought a large assortment with a large heavy duty storage box. Soooooo how to get them to turn black?

I used several inches on Klean Strip rust remover jell in a glass container and it took about a minute for the zinc to foam and come right off the screws (not all but about half of each size). After rinsing with water and drying I used another glass container and used enough Oxpho-Blue to cover all the screws. Let them soak for a couple minutes, then rinsed with pure water, dried then soaked again for couple minutes, rinsed and finally dried. I put them all in a baggy and sprayed in a bit of Rem Oil and they are nearly black. So I replaced the zinc plated screws with the new black ones, much better looking I'd say. I read somewhere that you can use vinegar also and I put this here in the muzzle loading section since I think it applies more to our type of firearms instead of the Gun Smith section.
John

[country gent]

A lot of those screw heads are hard from the forging process. Hardened metals will take longer to darken and may take a few applications.

[Winger Ed.]

I put steel screws in a little pill bottle with cold blue in it, and come back the next day.

I never ran into a zinc plated screw that needed to be done, but if I did, I think I'd sand off the plating first.

[LAGS]

I strip the Zinc off with Muretic Acid diluted in water.
Than most of them I just Lamp Blued them with a Torch and oil.
Others I have blued with cold bluing or slow rust bluing.

[elmacgyver0]

I use muriatic acid to remove the zinc plating.
Heat screw to red hot with torch then dunk in oil.
Produces a nice durable black finish.

[Backwoodsdave]

I often use a small propane torch to heat the coated heads red and the coating burns right off, a quick buff with my stainless brush, heat again and quench in oil, you can repeat the quenching until the desired blackness is designed, this method has worked good for me on many occasions.

[Geezer in NH]

TOW has un-plated screws.