Theory/Black Finish/M1 Garand

[eclancy]

Gentlemen,
On this post I am working on files which cover a black finish on the M1 Garand. I have a number of files dated in 1939 which talk about NOT using Parkerizing as a finish on the M1 Garand. It seems that a treatment called "Pentrate" being used seems to work but comes out "shiney". Then files talk about using "Parkolac" as a finish. Ordnance found that keeping the parts in longer gave a darker finish. You must understand that many files on the M1 Garand have been destroyed or lost over the years. No one thought that 60 years later these combat rifles would become collectable and data on them so important. What I am looking for from you guys is do any of you have data or info that could help us find out more about this subject. I am working on a theory about this but I want to hear your input. Yes, I think it's a interest problem. Here's one file on the subject.



Looking foward for your input about this theory.

Here's the other sites address:
http://www.users.fast.net/~eclancy
Thanks again
Clancy
NRA Life Endowment
NRA Training Counselor
NRA Instructor

 

[Poodleshooter]

Clancy: this seems like a good start: http://en.wikipedia.org/wiki/Parkerizing
Follow the patents to get more info.

 

[Jim Watson]

Pentrate is NOW a conventional black oxide finish. Was it then? Probably. The current owners of the brand name have only been doing it since 1942, likely it was orginated by someone else and they picked up the process and name.
http://www.pentrate.com/aboutus.html

Roy Dunlap lists Pentrate under the Parkerizing heading but says it "is more of a hot blacking solution."

An acid dip would have etched the steel to give a matte finish.
Dunlap says 25% hydrochloric (muriatic) acid for one to two minutes for commercial guns, 50% for one minute for dull military weapon finishes.

The only Google I get of Parkolac is in French from a 1975 Belgian surface treatment specification. As best computer translation can tell, Parkolac 1043 is a dye to darken a phosphated (Parkerized) finish and Parkolac 44 is a sealant of some sort.

 

[eclancy]

Gentlemen,
Great info. Maybe Ordnance did go to it later. That could be the reason why some M1 Garands show a black type finish today.
Thanks again
Clancy