Linseed oil bluing?

[commygun]

I was reading an old gunsmithing book and one of the contributers related how metal parts could be blued/blacked
by heating and then rubbing with linseed oil. Does any one
have any experience with, or comments about, this method?
I don't have any project guns going right now or I'd give it
a try just out of curiosity.

 

[MarineTech]

I have only ever heard of linseed oil being used on stocks. I have never heard of it being used as a blueing agent.

 

[dfariswheel]

There are a number of old bluing methods that use various oils.

The original Colt black powder revolvers were blued by heating the parts and rubbing with rags soaked in fish oil. Apparently this wasn't a very high-tec operation, just a couple of guys with a heating pit, a bunch of old rags and a barrel of fish oil.

Since Colt polished the parts to an extremely fine finish, these old guns have some of the best blue jobs ever put on a firearm.

A number of these old time methods are detailed in the book "Firearm Bluing and Browning".

I think Brownell's still carry it.

 

[DeBee]

This was a very old method of protecting the blued finish. After the gun was blued, the oil was applied- I don't think it was used in the bluing process.

Nowdays, we have better oils... I guess you could have your gun blued and slap on a coat of poly- it would last longer than the linseed...

 

[BigG]

As DeBee said, I remember reading about linseed oil being applied to the finish and making it look like glass in an old time book about browning, IIRC.

The fish oil story is new to me. I understood Colt heated their parts to a certain temp where it turned blue indicating the temper of the metal. In other words, the blue was a product of the heat treating process.

 

[dfariswheel]

The later Colt process used a heat bluing method, in which the parts were packed into small steel drums with a secret mixture of bone meal, charred leather, and other ingredients.
The drums were put into a temperature controlled oven and the parts came out that gorgeous Colt pre-war blue.

In the book "Colt Firearms, 1836 To 1940" by Haven and Belden, they give a chapter on a tour of the Colt plant in which they give a fair description of how a Colt revolver was made then. This includes a discussion of the pre-war bluing process.

Astoundingly, they describe Colt using HOT BOILING GASOLINE as a pre-cleaner.

Per an old book on the early Colt factory in the pre-Civil War era, the guns were polished to possible the finest quality finish ever done on a production revolver, then the parts were blued with the hot metal/fish oil rags technique.

Included was an early 19th Century-type pen and ink drawing of the bluing room.
Shown are two or three men gathered around what appears to be a low brick charcoal pit, rubbing parts with rags.

I'm not sure at what point Colt went to the oven blue system.
After WWII Colt changed over to the modern hot salts process.

I'm not sure linseed oil was used as an actual bluing method, but it was used as a protective coating for muzzle loading rifles and shotguns.
After the parts were browned, they would continue to rust and would quickly become rough and pitted.
So, boiled linseed oil was applied and allowed to dry into a varnish-like coating. This made the metal shine and protected the metal from further rust action

 

[GooseGestapo]

Sounds like a lot of dis-information to protect proprietary knowledge/information. Hot boiling gasoline is a sure -"fire" one shot deal !!!

 

[Shooter Solutions]

I can't believe anyone would say "boiling gasoline" .

Maybe the confusion is with boiling linseed oil.

If they used raw gasoline as the cleaner, after a few explosions, I would hope they learned to use something a lot less flammable, like kerosene.

That stuff is so explosive: you only want to put that into a gas tank. The tiniest spark with the right mixture of vapor and air: Flash fire.

Maybe it is an "old wives tale".

 

[dfariswheel]

I've wondered about that for many years.
The book has been reprinted a number of times, but was written in the 40's. The book is a famous "standard reference" for Colt collectors.

The author's took a special Colt tour, where Colt actually built them a Colt Official Police so they could see exactly how it was done.
They described the bluing process, and specifically said "boiling gasoline".

I always wondered if they just made a mistake or ?????????

 

[BigG]

I read the Colt book with the boiling gasoline, too. Who knows? They use cyanide and sulfuric acid in different processes, too.

 

[stevelyn]

I've heard of a "browning" method by coating polished and preped metal with beef tallow and baking it at about 200-250 F. Sort of like seasoning a piece of cast-iron cookware. It's supposedly very durable and the browned parts won't rust.