Please help with WRA finishes

[Garandrew]

Ive recently learned this WRA receiver is finished with zinc oxide, I am grateful, as I thought it was a faded du-lite!


Anyone know what finish used on this barrel?

Information

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[Hercules Powder]

http://en.wikipedia.org/wiki/Parkerizing

Use this link for information on parkerizing. It may be zinc phosphating not zinc oxide.

John

[Garandrew]

I meant zinc phosphate! Sorry

[FTD1167]

Receiver looks like bare steel to me.

[Garandrew]

Thats what I always was wondering about, there is no deep green park, but could it be a faded zinc phosphate, as Im learning the manganese phosphate was deeper green with the years, and cosmoline?
These pics were taken outside, with no flash..gray zinc phosphate finish, not a coating, as the process didnt coat?




No signs of buffing, polishing, finish removal, Ive had it 30+ years..

[BrianQ]

Thats what I always was wondering about, there is no deep green park, but could it be a faded zinc phosphate, as Im learning the manganese phosphate was deeper green with the years, and cosmoline?

It's the chromic acid rinse that imparts the green tint to the finish not the base metal of the phosphate coating or cosmoline.

[FTD1167]

From what I have read, Manganese was needed for other things during the war. Zinc and black oxide were used instead.
Ours are just 1575 apart.. Notice my slide does not match, I have since found an original slide, also my barrel is a blackish color like yours.
This is a good write up..

"Somewhat analogous to the improved manganese phosphating process improvements discovered by Baker and Dingman, a similarly-improved method was found for an improved zinc phosphating process as well. This improvement was discovered by Darsey of the Parker Rust Proof Company, who filed a patent in February 1941, which was granted in August 1942, U.S. Patent 2,293,716, that improved upon the zinc phosphatizing (Parkerizing) process further. He discovered that adding copper reduced the alkalinity requirement over what had been required, and that also adding a chlorate to the nitrates that were already used would additionally permit running the process at a much lower temperature in the range of 115 to 130 °F (46 to 54 °C), reducing the cost of running the process further. With these process improvements, the end result was that a low-temperature (energy-efficient) zinc phosphating (Parkerizing) process, using strategic materials which the United States had ready access to, became the most common phosphating process used during World War II to protect American war materials such as firearms and planes from rust and corrosion."

[Newscotlander]

....the end result was that a low-temperature (energy-efficient) zinc phosphating (Parkerizing) process, using strategic materials which the United States had ready access to, became the most common phosphating process used during World War II to protect American war materials such as firearms and planes from rust and corrosion."

O.K., with the above information in mind, we also know through Inland documents, that they were using Parco-Lubrite for their phosphate coating. Parco-Lubrite is a manganese phosphate coating. How does that fit in with the above statement?

There's no doubt in my mind that Winchester was using zinc phosphate on their receivers throughout production. Barrels appear to have a black oxide finish early and a zinc phosphate finish later. Winchester was even using zinc phosphate on, at least some, M-1 rifle production (see GCA Journal, vol 22, issue 2, pages 11-14). The finish on those two Garands match Winchester receiver finish.

Finish on carbines varied, depending on the prime contractor, the part, and the time period.

[Garandrew]

The barrel I believe is dulite finish.

[Garandrew]

Thankyou Chris, how would you classify the receiver finish on my WRA? 1108196? Zinc Phosphate is what Brian Q stated on another board? Mine and FTD,s are so close, but his finish is greener, but seems like the logo, and serial numbers on FTD's are more filled in with whatever finish it has??
I think my barrel has the earlier black oxide, or dulite finish..