doublegunshop.com - home Forums Thread Like Summary - Winchester Mod 21 Question re: Barrel Bluing

This relates to a nice 20 Ga Model 21 that I restocked a few years back. The stock came out great and I had the receiver blued (hot) and it came out great. I was thinking at that time that I should rust blue the barrels, which I did. They looked pretty good for a while, then not so much. I did them again with the same result. So I did it one more time with a few extra iterations of the rust blue; same story, now the conclusion: Winchester steel needs to be hot blued. I suppose the construction of the Winchester 21 barrels--dovetailing of the barrels and rib--at least the top rib (not sure about the bottom rib) was engineered into the design to enable them to be Hot Blued.
So I think I am finally of the opinion they SHOULD be hot blued. Now--who to send them to? I'm not set up to do it. Thanks, Gil

Winchester 21 barrels are rust blued. Don’t hot blue them unless you want more problems, e.g., the Keel rib and bottom rib might fall off. Send them to someone who knows rust bluing.

21's always blued the best when using the older formulas which contained the Mercury Bi-chloride or other such chems that will send us all to an early grave.

I've had problems doing 21 bbl's with MarkLee Express. The bluing develops a reddish coloration on some edges after a while and is not all that wear resistant as you'd expect from a rust blue.
Laurel Mtn Slow Rust has worked better as far as the above issues. But the need to allow it to rust longer (cycles) is hard to end up with a shiny surface. The LCS Field Grade look isn't my first choice on a 21 thought it is Blue and wears well.
Less rusting/shorter cycles and more of them doesn't seem to give the desired result. Only a weaker finish that wears easily.

I've got some of the Brownell's Orig Belgian Blue formula , the new issue stuff that is supposed to be the same as the original formula. That orig had Merc Bi Chloride in it.
I tested it back when I got iy by swiping some onto some warmed up clean brass surface. It plated out what appeared to be Mercury onto the brass just the orig formulas would do (Like Herters).
Smelled like it too.
So I never used it. I figured at that point I had inhaled and eaten enough silvery metal after 35yrs (at that point) of rust bluing.
Mark Lee's Express and L/Mtn for slow Rust.
I have a feeling that New/Old Belgian Blue formula may work pretty good on 21's but have never tried it.

Now I don't take on any rust blue projects anymore. I just do some of my own accumulated projects,,,and if I never see a Winchester 21 again it'll be way too soon.

FWIW, L/Mtn is known to afterrust quite easily and I had problems with it doing that as did/do a lot of people.
A couple things I found to easily avoid it..
1..after the last boiling and carding cycle of the L/Mtn,,go right after the surface and apply a coating of Mark Lee' Expree Rust Blue.
Just as if you had been Express Rust Bluing the piece all along.
Warm the metal if needed, thin coating, etc, etc,
Back into the still boiling water tank.
10 to 15 min pull it out and card it off.
Use your standard after blue oil procedure from there.
The Mark Lee single Express Blue coating for what ever reason kills the L/Mtn from after rusting.

#2,,and easier yet... After boiling and carding the last cycle of L/Mtn
Hang and let the parts cool a bit till just warm.
Then coat the parts all over with 'Refined Linseed Oil' I use some labled Winsor & Newton brand. It's an Artists supply thing.
Here's a link to some
https://www.dickblick.com/products/winsor-newton-refined-linseed-oil/
The warm metal will help to spread and cover the parts.
Let them hang and sit for a day at least. 2 is better.
The oil will be hardened or nearly so when you go to handle the parts and assemble but the coating will wipe off with a cloth dampened with your fav gun oil.

The best part of this is that the Refined Linseed Oil prevents any After Rust.
No blackened cloth or towels when rubbing down the parts afterwards or the next day or week.

Boiled Linseed Oil doesn't seem to do the same magic.
'Refined Linseed' does it.

Heat.

When rust bluing anything Winchester I don't use the slow process.
Below is a quick write up. Not getting into polishing, tools, rust solutions, etc. If you're familiar with the process, this will make sense. (Have a dinner date with my wife.)

Have water boiling, place barrels in boiling water after final prep.
Remove from water, blow crevices dry with compressed air.
Apply rust solution. If barrels are hot enough it should rust/evaporate almost instantly.
Boil barrels and then card.

Repeat as may times as needed. (Move quickly!)
I also keep a propane torch handy to keep things warm/hot but this requires CARE.
When done blacking and carding, coat heavily in non-detergent motor oil for at least 24 hours. Many oils have additives that will loosen rust blacking. As me how I know.

The use of a heat source is VERY common. You can even find YouTube videos from inside Turnbull's shop showing his guys using this method.
That said, stick to the cold rust method if you are not comfortable with the process.

I had some great mentors who gave me hints & tips, but my process is not exactly the same as theirs, so this is just a guideline to be adjusted to your shop, tools and conditions.
More than one way to skin a cat.

In my experience, using the method that UTSG described will work, but…and this is just my opinion….will only result in a low sheen, satin blacking that doesn’t look like original Winchester high sheen blacking. Even Mark Lee recommends blasting the barrels or parts with a fine abrasive before applying solution. It’s hard to get a high sheen black when you have to do that.
In order to both polish the barrels to “chrome” and then subsequently get the slow rust solution to gently bite into the polished steel, you need to develop a method that allows that to happen. That’s a trick I’m not quite ready to part with quite yet.
I have not had good luck getting Mark Lee solution to bite into highly polished steel. It doesn’t work very well for me on anything polished to 320 or higher.

I purchased a solution recipe from a friend in Montana (he’s out of the blacking business) and I’ve seen Winchester model 21’s and model 12’s he’s blacked and they look amazing, correct sheen, etc. This solution has both Mecuric Chloride and nitric acid in it, albeit in very very small quantities. The solution gives a beautiful deep, high sheen black on highly polished steel. It usually takes about 10 to 12 cycles to get the correct color, on high chrome steel and nickel steel, a few more cycles to get there. He got the solution recipe and method from a long gone Montana gunsmith who also restored Winchesters. I personally have not used the solution yet on a set of barrels, only on test coupons of steel.

I’m thinking you’re stopping a little too early on your cycles. Have you tried going 10 to 15 cycles and seeing if the black holds longer? Also, maybe try letting the barrels cure in oil (like utsg said, non detergent type, I use non detergent 30wt compressor oil) a bit longer than 24 hours. I sometimes let the oiled barrels sit for a few days. Get a clean paper towel to wipe the barrels down and if you see dark stuff on it, let them sit longer.
Ensure you’re also using a saturated solution of baking soda and water to neutralize and let them sit in that for at least an hour or two. That was a great and very helpful tip from an old time barrel blacker that I got a while back. It makes a difference.