SMLE factory bluing

[sam23]

Hi,
I have just bought an old '42 SMLE and am attempting to do it up. It is in pretty rough nick so wont be a small project. Most of the exposed metal is bare, the rest is rusted (not too deep). I will try to remove the rust and put a proper finish back on the metal.

I have taken it all apart and the outside of the barrel (which is covered by the wooden forestock) is in good condition. Although it seems to be blued, it does not look like the bluing that you would get on a modern rifle, it is more of a light grey. I have noticed many older guns have this greyish colouring as opposed to the deep blue/black but I had always thought it was just because the finish had worn away over the years. This barrel though should have been quite well protected.

Has the bluing process majorly changed since WW2? Did they use a different process that is now outdated? Or did they use a different process because they needed to mass produce rifles quickly for the war?

I would like to know what sort of process was used to blue these rifles (perhaps they even used different chemicals?) so that I can replicate it as close as possible to keep it "authentic". It is a Lithgow SMLE if that makes a difference.

 

[mete]

Maybe it's Parkerized rather than blued .We used that process also in WWII.

 

[sam23]

I thought that initially as well but it doesn't look like it is. Also isnt a parkerised finish meant to not wear off? It seems to me more like a bluing but I could be wrong. Does anyone know if Lithgow did parker some guns?

 

[T. O'Heir]

"...'42 SMLE..." Mine's a Brit.
Commonwealth didn't use Parkerizing. That's a commercial brand name used Stateside.
No 'bluing' either. Time consuming, expensive and didn't last well in tropical locations. Primary finish was oil blackening. Suncorite came later. That's paint.
Oil blackening is something you can easily do in your kitchen. Supposedly involves cooking, peanut or linseed oil, heating the steel in a 500F oven then dropping the steel into the oil. Lot of how-to's if you net search 'oil blackening'.
Flat black Krylon spray paint would do. Black phosphating would be better protection. Caswell plating sells kits for that.
"...this greyish colouring..." Could be just age. As daft as that sounds. Finish gets thin from years of guys playing with it and fades so the steel shows through. Or just a chemical reaction to years of storage. The green tinge on some U.S. rifles is caused by long term storage in Cosmoline.

 

[James K]

Pre-WWII SMLE rifles appear to have been rust blue, not heat blackened, but there is confusion because true oil blackening was done as part of the heat treatment process, as in the U.S. Krag. It couldn't be repeated, so rifles that had to be refinished were rust blued.

There has been a lot of discussion about the greenish color of U.S. Parkerizing, but it seems untrue that it was due to Cosmoline. In wartime, U.S. rifles were not shipped from the factory in Cosmoline; they were lightly oiled packed in wood crates. Cosmoline was used to preserve rifles for extended storage after the war.

The greenish color seems to have been the result of the Parkerizing chemicals used; near-new M1 rifles that show no evidence of ever being in contact with Cosmoline have a greenish tinge on the receivers but not on adjacent parts, like the barrel or sights.

Jim

 

[garryc]

 

[sam23]

I have always been a bit hesitant to use a finish that requires the components to be heated. My understanding is that in making a rifle, the barrel isn't heat treated but the receiver is heat treated to harden it. If I then heat the receiver in order to blue/blacken it, will I be destroying some of the heat treatment that the receiver was given to make the rifle safe? Likewise, if I heat the barrel and quench it in oil, will I be hardening that (which apparently is not good for barrels)?

 

[Slamfire]

It is a Lithgow SMLE if that makes a difference.

My Austrailian SMLE's are green parkerized. My newly parkerized parts were gray, I heard that Zinc-Nickel Phosphate Parkerizing solution will turn green after a period of time. Others claim that the green is from grease. http://www.hotflashrefinishing.com/Parkerizing.htm

If you conduct a search of gun Parkerizing services you will find lots of firms who will refinish your rifle. This is just a list of firms I saw and some appear to offer different colors of parkerization.

http://shuffsparkerizing.com/services/parkerizing/

http://www.craftguard.com/parkerizing.htm

https://dgrguns.com/0-main-page-services.htm

http://gunblack.com/gun_refinishing.html

http://www.krcrefinishing.com/id2.html

I have a 1916 Austrailian SMLE, and the little finish it has left, is bluing. It must have been a beautiful rifle before going through two World Wars. I have seen nice WW1 era British SMLE's and they appeared to be blued. WW2 British No 4's were painted black. Canadian No 4's were parkerized and blued. Have examples of both. My Savage Arms No 4 has a painted black protective finish, I have not scrapped it off to see if it is over parkerization, but it could be.

 

[James K]

From the beginning of the 20th century to about 1935, there were only three kinds of "bluing" used on firearms.

The first was rust bluing, an old system of artificial rust that differs from "browning" only in the chemicals used. It is durable, and easy; the chemicals used are not especially hazardous. The process is slow, but in mass production takes no more time than any other process, since many items are in the pipeline at the same time. It was the only method used by small shops.

The second was Carbonia blue, a process developed by the American Gas Furnace Co. It was used, AFAIK, only on handguns. It gave beautiful results but heated the work so much that it was part of the heat treatment process and could not be repeated.

The third, previously described, was oil blackening. It was the result of quenching hot work in oil and also could not be repeated. The finish was black, not blue, and was not very durable, often chipping off in spots. It was used on receivers at Springfield Armory in the Krag and early M1903 period. Receivers that had to be refinished were rust blued.

Heat bluing, or the bluing of steel by direct flame or heating was used on small parts, but mainly as a result of the tempering process; it is not durable, and was never used (AFAIK) on rifle receivers, only on small parts, mainly springs.

In the mid-1930's, hot tank bluing with chemical salts was developed. It was both easy (though it had to be carefully controlled), and fast. Collectors are familiar with the changes from rust blue to tank blue in guns like Winchesters and Lugers.

Jim

 

[sam23]

Here are a couple of photos of the barrel. Is anyone able to tell me what sort of finish it has?

Is there a way to tell what process they used by looking at the stamped markings on the barrel/receiver? Aren't they used for factory inspections?

 

[mete]

As I remember there are two Parkerizing types.One gives a green and the other a grey color ! It's a phosphate coating , zinc phosphate or manganese phosphate !

Even WIKI agrees with me ! I remembered !!!

 

[James K]

It has the appearance of old rust blue that has been cleaned and oiled many times until it is essentially patina. The markings are proof and inspection marks and don't indicate any specific finish.

FWIW, barrels are heat treated. Receivers are often not only heat treated but surface hardened for durability. Tank blue does not get the steel hot enough to affect heat treatment, nor does rust blue which never gets the work hotter than the temperature of boiling water. Carbonia blue and oil blackening do get hot enough to affect the steel, and those are almost always done at the factory as part of heat treatment.

An interesting sidelight on Carbonia blue. When Colt began magazine production for its auto pistols, it used that process. They tempered the steel, but then found out that furnace bluing took the temper out of the magazine feed lips. But they had no other rapid bluing process available, so they blued the magazines, then dipped the feed lips in molten lead to restore the temper. That took the color out of the area the lead reached, and was the reason for the "two-tone" magazines. After they got hot salt bluing in the 1930's, they tempered the magazine lips before bluing the entire magazine, and the two-tone mags vanished.

Jim