I can rust blue!!!

[Stophel]

Hot dog!  I can rust blue!

I tried an experiment today to see if I could do it.  I tried once before some years ago, and got a nice blue-black color, but a muddy brown underneath it when in the sunlight.  Well, I tried it again.

I did this triggerguard.  Just the bow and grip rail section.  Wasn't worried about the rest.  I polished it about as close to mirror bright as I cared to.  Brought out the old bottle of Herter's Belgian Blue.  I got a pot boiling with some pure water.  I would heat the part with a torch, hot enough so that when I applied the stuff, it evaporated off real quick.  I put the stuff on, rubbing it on quite a bit, then I put it in the boiling water for a few minutes.  Took it out, rubbed off what little rust was on it with steel wool, and repeated.  Over, and over, and over.  I don't know how many times I did the cycle.  Several.  Probably more than was necessary, but I wanted to be sure.  I was actually worried that the more I got on, the harder it would be to get rid of the brown color, but actually, the more I put on, the better it looked, and the more the brown went away.

What I ended up with is this deep, satin dark blue-gray, which is exactly the finish I have been told that rust blueing is supposed to produce.  I'm not sure, but I don't think it's possible to make a mirror bright blue like a modern hot blue.  The stuff etches the surface of the metal, and you have a satin, "micro-crystalline" surface.  And, best of all, I have ZERO brown color left! None whatsoever.  Not in any kind of light.  No muddy brown.  I'm happy.

I think this will make a durable  finish, which it is widely reported to be.  I was scrubbing it down with steel wool, and it wasn't wearing the blue off the corners or anything, so it seems pretty tough.





My first real project with this is going to be my S&W M22-4.  It has been "delocked" (if you are familiar with the current infernal lock system, you know what I mean) and the holes filled, the slot beside the hammer has a slip of steel soldered in place.  Supposedly, they MIGHT melt off the solder if someone tries to hot-blue it, so rust blueing is the "safe" alternative. (I can't imagine that they get it hot enough to melt tin, but that's what they say...)

I am convinced that rust blueing was done in the 18th century, but am unable to prove it.  I've seen 18th century locks and mounts that SEEM to be rust blued, but can't say for sure.

I have a barrel blueing tank (48" long) that I can do barrels in.  I guess the best way for me to heat it is to build a long wood fire under it.

I'm ready, I'm ready, I'm ready....

[Evil Monkey]

Great results Chris. I have a 48"x6"x6" blueing tank and I just put it on a two burner propane camp stove for rust blueing. I only put enough water in it to cover the barrel, maybe 2". The stove won't quite get it to a boil but it gets hot enough to turn the rust blue.

[sydney]

Hi Chris--I made a long propane burner using 3/4" sq tubing
               It made have taken 1 hour or so to build but boils water very fast
               I don t know if it is needed but i like to boil the parts for 10 to 15 min
                in a good rolling boil
               If you want info on the burner let me know
                   Sydney

[Stophel]

I intend to blue a smoothbore barrel soon that is going in my own personal gun (yes! I'm making one for myself!).

Anybody have any photos of their finished rust-blued barrels?

Oh, and do you get the same type of results doing a "slow rust blue", rather than the "fast rust blue" Belgian blue that I am using?

[FG1]

Chris , it isnt that the hot blue melts the lead solder but the sodium hydroxide in the salts eats it . Many a fine double barrel were ruined over the years by those not knowing .

[Stophel]

Chris , it isnt that the hot blue melts the lead solder but the sodium hydroxide in the salts eats it . Many a fine double barrel were ruined over the years by those not knowing .

Gotcha.  Thanks!

[Dphariss]

I intend to blue a smoothbore barrel soon that is going in my own personal gun (yes! I'm making one for myself!).

Anybody have any photos of their finished rust-blued barrels?

Oh, and do you get the same type of results doing a "slow rust blue", rather than the "fast rust blue" Belgian blue that I am using?

I try to use well aerated water, shoot it into a bucket at high velocity with a hose to mix air well.
I always boil parts for at least 20 minutes starting with water boiling when the part is put in.
Grey blue means you need another coat or two when doing the "long method", unless thats what you want.
This finish is VERY tough and hard. This barrel is darker in real life than the photos indicate about as dark as the typical "blueing salts" blue.
This takes about 5 days to a week+- using homemade nitric acid solution. Note that NA will give better blue IMO than most rust solutions. I have used Wahkon Bay Brown and Wahkon Bay Aquafortis stain mixed about 50-50 with great results even on 4140/4150. The pistol barrel is a GM. Browning solutions without nitric will sometimes stop rusting at the grey blue phase and this is too light for me.
I have a tank made from a piece of 4" square steel tubing with the top cut out and plates welded at the ends. But i need a new one the one have have is a little short. About 44". Need 50" really. I use a two propane camp stove and a single burner hot plate for heat (hot plate is a recent addition).  Card with degreased 0000 steel wool.
Dan

[keweenaw]

I've done a ton of slow rust bluing over the years, using various homemade and commercial formulas.  What I like best is Pilkington's slow rust blue sold by Brownell's.  I've never found it necessary to boil pieces for more than 5 minutes and have never, ever gotten a brown background color.  The slow rust blue will give a slightly more satin finish than the express type blues and of course takes about a week to do depending on the humidity - on good humid days one can do two coats a day, on dry days only one coat.  I usually go for about 8 boils.  The trick on any of these blues is to have the piece of metal absolutely degreased, never touch it with your fingers, apply the bluing agent to the metal when the metal is warm, and don't put on too heavy of a coat of the bluing agent.  When you're using the agent on a barrel, squeeze most of the stuff out of your cotton ball or swab such that when you make a pass the entire length of the barrel, the end you started on will be about dry by the time you reach the other end of the barrel.

Tom

[Stophel]

Well, when I'm in the sunlight, it's a very dark blue-gray.  When I'm in the shade or in the house, it's black as the ace of spades.

I did a rifle barrel years ago, and got a nice black, but when I took it outside, it had a horrible muddy brown color showing through.  No amount of boiling would get rid of it.  I was using hard water, and have been told that that could have been the culprit.  Or just the fact that I didn't know what I was doing...

[keweenaw]

If you don't turn the oxide black from each coat of the blue you can get that brownish background.  Another thing that will give off colors is if the surface of the metal isn't absolutely clean when you start.  Traces of oil will give yellowish areas.  Different steel alloys will also color differently.  I express blued a Rigby rifle that had one type of steel in the barrel, another type in the rear sight base that was affixed to the barrel, still another in the barrel band and a fourth type in the banded front ramp.  No amount of work would make all those take the same color despite the fact that they were identically hand polished, degreased, etc.  Some current investment casting have alloys in them that I have trouble coloring with an express blue but not with a slow rust. 

The ideal rust blue is the accumulation of many thin coats which uniformly blacken the surface.  None of the rust bluing techniques will give the deep blue black of a hot caustic salts blue or a superb high gloss charcoal blue.  Almost any water will work for the boiling as long as it's not hard.  My dad who probably rust blued 400 doubles routinely used rain water.  My fairly soft well water seems to work fine too.

Tom

[Dphariss]

Well, when I'm in the sunlight, it's a very dark blue-gray.  When I'm in the shade or in the house, it's black as the ace of spades.

I did a rifle barrel years ago, and got a nice black, but when I took it outside, it had a horrible muddy brown color showing through.  No amount of boiling would get rid of it.  I was using hard water, and have been told that that could have been the culprit.  Or just the fact that I didn't know what I was doing...

Our city water comes out of the Boulder River and while not super hard can't be "soft" either coming out of the Mountains.
I boil 20 minutes because I boil 20 minutes. The oxide will turn black pretty quick but I am a creature of habit. May have gotten it from Angier's book.
I have used distilled water with no change in the result.
I think this is the best finish for barrels far tougher than any brown and no scale/rust etc in the bore.

Dan