Slow Rust Blue process ?

[CedarGrove357]

Hi folks-
I searched the forums attempting to answer a process question on rust bluing. I didn't find what I needed, although I am sure its been posted before.

What do you use to seal your bluing jobs when complete?

My process list is below.

I have been doing several re blue jobs, and I've noticed that after a few days, the bluing creates a new layer of black rust on the barrels; very light and finer than dust. I believe I am not getting the bluing sealed at the end of the process like I should be. A wipe down with gun oil [specifically, Lucas Gun Oil] removes the layer and the part looks good again. Here's a pic of an UltraSlug I recently did:

https://www.dropbox.com/s/v7ohrvelnk...0x520.png?dl=0

My process is as follows:

1. disassemble firearm
2. boil parts in water to convert rust and loosen any hard rust
3. card parts to remove loosened rust, wipe down.
4. apply rust solution [Brownells Classic Rust Blue is currently in use]
5. let dry an hour, reapply second coat, allow to dry
6. wait 24 hours to allow parts to rust [50+% humidity], longer if not quite rusted enough. [Speed isn't a factor with this method for me, although I can accelerate the process if needed/ too low ambient humidity.]
7. Steam parts to convert new rust
8. card parts and wipe down with a clean blue shop towel.
9. hang and allow to rust again naturally [nope, no more salts]
10. Rinse and repeat for 7 days minimum
11. After final carding, dry heat parts to 115 degrees [just the temp my heater blows into the box] in a heat box and soak in kerosene for an hour. Remove, wipe down and blow off any excess
12. coat with gun oil/liquid wax mix and wrap in paper and rest for 24 hours before assembly.

Thanks for the advice.

[Scorch]

One of the first steps in refinishing any gun is to remove old finish and polish the metal surface to remove surface damage and corrosion. You didn't do that, it shows. Then you start rusting, boiling, carding, rusting, boiling, carding. At the end, seal with oil or grease. The rust blued surface will absorb the oil and hold onto it, keeping the metal from rusting.

[Nodak1858]

I have rust blued a number of long guns and hand guns. I striped the old finish, degreased the daylights out of the parts. Joints are tough where the barrel meets the receiver, or sights attached ect, have to work to get all the grease/oil off. Then I coat with Mark Lee Express solution, faster and has good results with it. I used to use the slow stuff but I haven't used it after the Mark Lee stuff. Then it's just like Scorch said, rust, boil card over and over. When I'm happy with the color I boil and extra long time at the end, then blow off the water and hose it down with WD40. Usually it ends up sitting overnight, I clean up tank and supplies and what not. Then I oil and clean it thoroughly, until the metal doesn't leave any color on the rag and then I'm done.

[CedarGrove357]

Thanks for the reply Scorch -

I didn't include the minutia for the prep because the process wasn't the focus; however, a little background with this gun - it was left in a barn for a couple of years, lost. It had major rust and corrosion over the entire length of the barrel and receiver.

I completely disassembled the firearm, boiled the barrel and receiver to stop the rust and preserve any original bluing left on the gun.

Cleaned with non-chlorinated brake cleaner inside and out including patching the bore.

Draw filed off the major rust spots.

Mounted the barrel in a "turning lathe" [basically, a chuck and tail stock driven by a motor and belt, used only for polishing barrels] and polished the barrel.

The imperfections seen are the pits and leftover damage caused by the rusting [it will never be "new" again].

The customer knows they will not come out. After that, I did the carding, rusting, boiling, carding a cycle of 7 to 10 times.
Then I heated the barrel and immersed in kerosene for an hour to displace any moisture. After that I liberally coated in Lucas gun oil/liquid wax mix and wrapped in clean paper for 24 hours.

This should have sealed the bluing as you said.

When this barrel is wiped down and the "black debris" is removed, its like glass. the image was to show the issue at hand.

Not sure what "You didn't do that, it shows" I didn't do. Any helpful suggestions would be appreciated.

Best of 2021 to all!

[CedarGrove357]

Originally Posted by Nodak1858

I have rust blued a number of long guns and hand guns. I striped the old finish, degreased the daylights out of the parts. Joints are tough where the barrel meets the receiver, or sights attached ect, have to work to get all the grease/oil off. Then I coat with Mark Lee Express solution, faster and has good results with it. I used to use the slow stuff but I haven't used it after the Mark Lee stuff. Then it's just like Scorch said, rust, boil card over and over. When I'm happy with the color I boil and extra long time at the end, then blow off the water and hose it down with WD40. Usually it ends up sitting overnight, I clean up tank and supplies and what not. Then I oil and clean it thoroughly, until the metal doesn't leave any color on the rag and then I'm done.

Thanks NODAK1858-
I just received a bottle of Mark Lee's solution but haven't tried it yet. You and SCORCH have substantiated my process isn't in left field somewhere. I have found that an initial boiling of the parts will squeeze out oils that I wasn't able to get to by hand cleaning as well as stop the corrosion even in places I don't cover with solution such as inside receivers.

I've done several of these types of issues - mostly turned down by other "smiths" who are too busy or don't want to mess with a useless gun. If a customer's willing to pay for the work, and understands they aren't getting a new gun back, but one that will work and will look better than a rusted tucker, then so be it. This ultraslug is one that has shown this "re-rusting" issue after wiping down and considering complete. I don't want to assemble the firearm and hand it back if they get black hands from touching it.

I was questioning the solution, thinking maybe it had expired, and including myself as a possible variable.

Best of 2021 to all!

[4V50 Gary]

I've done the same process with browning.

Know your environment. In San Francisograd, you don't need a sweat box. I made one with a lighbulb and a tuna can of water. Thing overrusted and required me to remove the rust. Next time I started, it was w/out the bulb or the tuna can of water. Thing browned nicely b/c of the humidity in the area.

Now I live in the high desert and probably use the light bulb and can of water.

[Tom-R2]

I did a 1911 frame and slide, after I reached the level of bluing I wanted I just kind of buffed it a little with a micro fiber cloth and put the parts in a ziplock bag with some clean new motor oil (Mobil 1). Let it set for a couple of days, then wiped it down well. I've not had any issues.

[CedarGrove357]

I agree with knowing your environment. My basement is much more manageable, and I have a dehumidifier to regulate the humidity. I have a heat box as well with a heater and a travel ultrasonic humidifier to manage better. However, as you experienced, an overnight rusting produced excellent results, and I could use a steam tower to convert the rust instead of the heat box method. Now I only use the heat box for dry heat before soaking in Kerosene to lock the blueing.

So far it seems what I may not be doing is wiping the final product down enough until I get all of the loose black rust off.

Thanks guys for the input.

Best of 2021 to all!

[Scorch]

Now I live in the high desert and probably use the light bulb and can of water

I went through my apprenticeship in Reno, NV. High desert to say the least, and I couldn't get anything to rust blue decently. So one of the guys in the shop built a cabinet. That helped a little. Then we put a small dish of ammonia in the cabinet. Instant rust! Too aggressive if you didn't watch it closely, but it worked. Using rusting agents helps, but you need to have some moisture in the cabinet.

[Unclenick]

CedarGrove357,

The thing that stood out for me as odd in your step list is using steam rather than boiling water for the rust conversion. The old process I am familiar with is as Scorch described, using the steam to cause the rusting, and boiling water for conversion (I always used DI water, but today would use RO water as it is cheaper to obtain). The only difference is, I used a watch glass or Pyrex custard dish with a few drops of nitric acid in it rather than ammonia. Both have nitrogen and hydrogen. The nitric fumes add oxygen, though the air can supply that, too, so they may work equally well.

Using steam for the conversion is interesting. It will be hot enough and it will certainly avoid minerals in the water spotting the work. But I don't know if it affects the blue bonding in any way without experimenting with it.

[CedarGrove357]

The steam idea came as my process of bluing when I was learning about rust bluing from the makers of RustBlue. Since then I've seen other variations on the theme, but what I've found worked best for me so far is the steam method. basically I took a 4' piece of 4" PVC Sch40 pipe, a toilet flange and a steel cook pot and built the steam pipe. It works good, but its a onesie fit so not much production can be done at once.

Interesting about the nitric acid in the hot box. My hotbox is a wooden box with a lid that I made with a door at the bottom. I can hang multiple items in it for more production, I use a personal heater and a humidifier in there to cause the rusting. The chemicals are already wiped on the parts to blue, therefore it minimizes the amount of acidity in the air.

I collect the condensate from my humidifier into a cleaned and covered bin, then I pump that into one gallon containers for storage. Its basically rehydrated water vapor, and my testing has it <30ppm total dissolved solids and the ph is about 6. Perfect water, in fact its better than the city water around here.

I received a donation of caustic bluing tanks from a departed gunsmith, so this year I plan on making a building outside to fire them up. We will be going over the process in detail in school this semester so it will be really neat to take that home and be able to expand on my experience.

[Unclenick]

I just reread Howe's process (p. 211 (formula 4, 10-day process) in Howe's Modern Gunsmithing, volume II) and he carded before conversion. Again, no idea whether that affects adhesion or surface sealing or not.