Johnson metal finish

[Joseph Scott 0]

Most of us have assumed the finish on 41 Johnson's to be a dark Parkerizing and I have used this process for my new parts. However, a number of drawings call out for the part to be "Blacken", other drawings call out "Parkerize", They indicated different processes. I got Dr. Rex McCellan, of Rice University, to run tests to determine what was used on receiver parts. He used a scanning electron microscope to do a surface element anaylsis on two guns. A "first" series and a "B" series. Both tests showed that there was no phosphorus, nor zinc, present, the finish is 85-91% iron oxide with O2 and sodium present is small amounts. This seems to indicate the dark color was/is a bluing finish, not a phosphate. A very small amount of managanese was indicated from the base metal. Whatever the process, it has proven to be very durable and indicates the high quality of production. My belief's have swung towards bluing versus "parking" but are still open for more input. Perhaps, Jim Pullen's research for his book will uncover more information.

Meanwhile, I am going to run some bluing tests on various parts. I know Garand parts were tumbled for surface finish, has anyone ever heard of Johnson using tumbling for parts? Various surfaces are smooth, that I can not envision any other way to make them so. Comments?

[Brian Alpert 0]

Joseph, What an interesting find. What did he scan...the receiver? I wonder if the other parts like the bbl or butt plate were also blued or parked. I have an "A" prefix that has obviously NEVER been polished or bead blasted from looking at the markings, and it is blue-black (receiver).

[Joseph Scott 0]

He actually scanned the bolt stop plates as they would fit in the scanning microscope. He has two very nice original guns that were displayed at Houston. He is originally from Leeds, England, and has some of the most outstanding firearms of anyone I know of. He specializes in failure anaylsis and is well known in his field. Testing was done without charge.

I have been playing with bluing to match old 1903 Springfields. I get a very dark blue at 295degF. If I add manganese dioxide, it becomes black. Get above 300degF and it tends towards red/dark brown. Color is temperature dependent. This may explain the magazines and rear sights which appear blued (they really were?). Bluing was an accepted finish for most military guns and could be mixed up by anyone. Parkerizing was/is patented and had to be purchased as a solution from Parker Rustproofing Co. Has anyone found any records concerning this subject?

I am still interested in preping the metal. Inside the receivers, they are very smooth and burr free. I think they may have tumbled parts in sand as did Springfield Armoury. Any information from old employee's?