predipping in cold blue before parkerizing?

[HisSoldier]

I saw a youtube video where the guy did this, I'd never heard of it. He said he gets better deeper black color that way. Of course he was using manganese parkerizing solution.

I did a Springfield 38 Super 1911 a while ago, turned out as a beautiful green color, can someone also tell me what base solutions give different colors? I'm hoping for black with my next one, a 1903 pocket hammerless, one of the 38 ACP models with two links. I have manganeze solution.

It was badly rusted on the slides sides and I surface ground the rust away, looked into replica roll marking but it's too expensive. Being the gun is in a oddball cartridge and that all the double linked guns are weaker I won't be firing it much. The little cross bolt that holds the slide together has been said to be a weak point.
Thanks ahead for any suggestions on parkerizing it.

[Jim Watson]

Hadn't heard of that. Brownels sells a "pre-dip blackener" to ensure black Parkerizing.

I have heard of hot bluing over Parkerizing for a flat black finish. I have a GI hammer that was cold blued over Parkerizing and it is very black.

[T. O'Heir]

He's confused. Parkerising isn't transparent in any way, shape or form regardless of what you do.
"...for a flat black finish..." All manganese based Parkerising comes out flat black. So does black phosphating.
And there's no such thing as green Parkerising. Any green tint seen on military firearms was caused by long term storage in Cosmoline. You get shades of grey depending on the metal with zinc based solutions. And black with manganese.

[Jim Watson]

Any green tint seen on military firearms was caused by long term storage in Cosmoline.

OR by the chromate sealant dip that was and may still be part of the mil-spec but nobody wants to handle the chromium salt solutions necessary.

[HisSoldier]

My green SA 1911 came out of the bath olive green. I bought my parkerizing kit in ebay. "Shooters Solutions", or that bottle may be from an earlier park I did on some commercial machine parts, I'm not sure.

This guy (http://hotflashrefinishing.com/Parkerizing.htm) describes various colors available, and I've heard of and seen variations in intensity because of part alloy characteristics and/or heat treatment. If heat treatment that's scary because it's common to spot HT areas of hard use like slide stop notches.

In one youtube demonstration the frame of a 1911 came out quite noticeably lighter in color, and uniformly so. It wasn't unpleasant to look at but that's not what I want to see on mine.

Brownels sells a "pre-dip blackener" to ensure black Parkerizing.

That must be what it was. The way it acted was exactly like dipping a part in cold blue, so I assumed that was what it was. But that still begs the question as to whether or not parkerizing is transparent to some degree.

Thanks for the ideas on this.

[RickB]

Both of the parkerized Springfields I've owned, three if I include the Garand, had a distinct green tint, right out of the box.


I have heard of bluing after Parkerizing, which is kind of interesting, since literally every refinishing process I've heard of appears to involve a meticulously clean, bare surface as the starting point.

[Jim Watson]

Well, the Parkerizing has to be dry. And since it retains oil so well, best to go straight from the Parkerizing tank to the bluing tank to avoid a lot of degreasing.

Parkerizing is not transparent. The blackener has to work chemically. They don't say how.

[HisSoldier]

A funny thing happened on the way to photograph my green Springfield 1911, it turned black! Must have read my mind. Curiously the dull black on the slide is darker than that on the frame. It's hardly noticeable but is when you look hard at it.
It's some weird trick of my mind that I remembered it being dark olive green. BTW, I love that gun, 38 Super with fully ramped barrel.

[4V50 Gary]

At Lassen College, we got the "green" color after parkerizing by immersing the workpiece in a tank of hot water with GI grease melted in it.

[mete]

You shouldn't have invent new ways to color the steel . Parkerizing is a trade name for phosphating the steel . There are two compounds used giving a black or green color That is Manganese phosphate and zinc phosphate. Parkerizing doesn't make the gun more rust resistant other than being able to hold more oil or grease to protect the steel.

[Unclenick]

Brownells sells both manganese and zinc sourced from the Parker company itself, so it is original. In its plain state, the manganese is charcoal gray and the zinc is light gray.

From: MIL-DTL-16232G

1.2 Classification. Coatings are of the following types and classes, as specified (see 6.2):

Type M Manganese Phosphate Base
Class 1 Supplementary preservative treatment or coating, as specified
Class 2 Supplementary treatment with lubricating oil conforming to MIL-PRF-16173, Grade 3 or MIL-PRF-3150
Class 3 No supplementary treatment
Class 4 Chemically converted (may be dyed to color as specified)
With no supplementary coating or coating as specified

Type Z Zinc phosphate base

Class 1 Supplementary preservative treatment or coating, as specified
Class 2 Supplementary treatment with preservative conforming to MIL-PRF-16173, Grade 3 or MIL-PRF-3150
Class 3 No supplementary treatment
Class 4 Chemically converted (may be dyed to color as specified)
With no supplementary coating or coating as specified

3.2.5 Chromic acid rinse. (Classes 1, 2 and 3). The chromic acid rinse of classes 1, 2, and 3 shall be performed in accordance with the following:

a. The final rinse shall be hot 63 to 93oC (150 to 200oF) chromic acid or chromic phosphoric acid solution: approximately 300 grams chromic acid flake in 1000 liters (L) of water.
b. The final rinse shall be maintained at a pH of 2 to 4 by the addition of flake chromic acid or mixtures of chromic and phosphoric acids. The pH of the final rinse shall be checked at least every 8 hours.
c. The final rinse shall be checked by a standard free and total acid titration or pH reading as often as is necessary to assure that the bath remains within the limits set at all times during which it is in operation.
d. All rinses should be discarded whenever they become contaminated. The final rinse shall be checked at least every 8 hours and shall be discarded when the total acid reading rises to more than 7 times the free acid reading.
e. The item should remain in each rinse for a minimum of 60 seconds.
f. Following the chromic acid rinse, the item shall be thoroughly dried before application of a supplementary treatment, as applicable.

3.3 Stress Relief. Unless otherwise specified (see 6.2), parts with a surface or throughhardness of Rockwell C 39 or greater shall be given a stress relief treatment. This includes carburized, induction hardened, flame hardened, etc. treatments. Also, any part that is ground, cold formed, cold straightened, etc., that may induce residual tensile stresses after machining or heat treatment shall be given a stress relief treatment. The stress relief treatment shall consist of a heat treatment at 177 to 204°C (350 to 400°F) for a minimum of one hour for every inch of thickness but not less than one half hour for thicknesses less than one-half inch. Optional heat treatment for carburized parts is 104 to 155oC (225 to 275o F) for 8 hours.

3.4 Hydrogen embrittlment relief heat treatment.

3.4.1 After coating. Unless otherwise specified (see 6.2), parts (including carburized parts) having the hardness values shown in Table I shall be given a hydrogen embrittlement relief heat treatment after coating per Table I without any parts developing cracks.
3.4.2 After baking. Unless otherwise specified (see 6.2), all lots of parts or materials for which baking is required shall be tested for hydrogen embrittlement.