I'm trying my hand at rust bluing (using a bar of 4140 for practice). I'm using Pilkington's solution and a brand new tank from Brownells.

I've followed the instructions to the letter but it appears as if the rust isn't turning black- when I card it off, I get red rust. I'm using distilled water.

Do you change your water between boilings?

Due to the humidity here, the tank has a good amount of rust inside- is this a problem?

My thought it that I need to give the tank a good scrubbing and change out the water, any other tips?

Thanks in advance for any advice.

The only things I can think of might be weak/worn out blue solution or the ferrous rusty tank. I use tap water and a stainless tank and change the water after maybe the 3rd or 4th boil.

The blue solution is brand new. I'm gonna scrub the tank and give it another shot.

Is the piece overpolished? I go to 240 grit which opens the metal surface just enough to get a good bite with the rust blue solution. Also ensure part is clean. I use a strong commerical cleaner and boil part for about 15 minutes before starting the rust blue process. 4140 should blue without issue. Sure you don't have a piece of stainless or high nickel alloy?

Polished it to 400 grit which, by most accounts, is fine.

It's definitely 4140, it was rusty from being in my shed before I polished it.

The tank is clean so we'll see.

quote:

I've followed the instructions to the letter but it appears as if the rust isn't turning black- when I card it off, I get red rust.

I to had problems with my first try, so built a blue box for next attempt. I have a health issue to take care of before I do it. Sooo I watch for this kind of thread for answers or problems that may come up. The above statement is messed up... did you mean you get red rust after the boil and then no black after carding? I'm just asking so when I start maybe it wont happen to me and someone has a good answer for you...I dont!

What are you useing to card the part off? Can a person use to much pressure against the part and remove blueing? Throwing this out for others with more experience...hell I'm learning too! I'll give it a try when health is better, but its back to hot caustic if it doesnt work.

Essentially, the red rust stays red, even after boiling. I am carding with a Brownells carding brush using very light pressure.

I feel silly saying this, but you might try different "distilled" water. I have found that our tap water here will not turn the red rust to black, so maybe there is some contaminate in the distilled water that is doing the same thing?

And I would clean the tank very well.

I may try that. I scrubbed the tank clean today and tried again- same result. The rust is also very light, I don't have a means of comparison but it sure seems like I'm not getting enough rust. I'm in Florida and working outside so I'm pretty sure it's not for a lack of humidity.

I will try a different brand of distilled water. If that doesn't work, I may try a different solution.

Try a small piece of the same steel,,small enough to boil in a pan inside on the stove top.
That'll take the new Brownells tank out of the equation for now.
More importantly,, it beats boiling all that water each time just to practice.
I use a simple aluminum bread pan on the stove to rust blue parts.

I'd suspect the water first off and try another source,,even tap water just to see if it converts color.
Even if you get uneven blue because of minerals/chemicals in the tap water,,at least if you do get the red rust to convert to black(blue) rust,,you'll know it was the water.

I've used the AC condensate for rust bluing for many years. I collect it in cleaned out plastic milk jugs and also fill a 35gal (new) plastic trash barrel with water every summer.
The barrel is on a small wooden frame on caster wheels so I can move it around if needed but I've never needed to so far!
I use the water out of the barrel after the jugs are gone. Filling carefully so as not to disturb the water too much. You'd be surprised how much debris filters out and falls to the bottom of that barrel.

It's been a good hot/humid summer so far for water collection from the AC unit. Never a problem using the water from it. I change it out every 3 or 4 cycles when doing slow rust bluing.
Just keep adding when doing quick rust bluing.

Even a light coating of rust should change over when boiled if everything is right. When doing the bluing itself, a heavy coating only accomplishes a more matted finish as it etches the steel.
A high polish isn't needed to get started. Unless you're very carefull and can manipulate the rustings and cardings correctly, you'll loose the high polish anyway.

Sometimes if the temp & humidity isn't quite there, I have to recoat the parts once again after the initial coating to get them started.

But that's in the winter with the house at 65F and the humidity way down because of it. Even then using Laurel Mtn solution, I can get it to rust OK,,but it can take about 24hrs per cycle.
Right now outside in the heat and humidity, it takes about 1 to 2 hrs.

Good Luck,,you'll get there!!

How long are you boiling it? I'd give it at least 10 minutes. Also, check your water. Some so called distilled waters have been run thru a water softener that contains carbonates. These will keep the rust red.

2152- Boiling a smaller piece in a different container is a good idea, I will give that a try. I am also just doing handgun parts at this point so I am going to have a local sheet metal shop make me a smaller tank so I'm boiling less water.

Bobster- I have boiled it anywhere from ten minutes (Pilkinton's directions) to more than thirty and it doesn't seem to matter.

My next steps will be:

-Same water, different container

and, if that doesn't do the trick;

-new water, different container.

I only want to change one variable at a time so I can diagnose the problem.

Thanks for all of the replies.

I'd bet a Big Mac it's the water. Use "steam distilled" It must say steam distilled. There is a "pressure distilled" and is pure enough to injet into your veins, but not good enough for rust bluing

Thanks, Duane!

It has to be the water- I tried a different container with no change. The steel came straight from Speedy metals so I have confidence that it's 4140.

Going to regroup, order my new container, and look around town for steam-distilled water. I may even switch to the Laurel Mountain Forge product as it's allegedly more forgiving.

One final question, since rust is such a problem here- does anyone know if using galvanized steel for my new containter will pose a problem?

Better yet, steam the parts instead of boiling. Steaming eliminates water problems. You can do small parts in a 4 qt pot with a lid, suspended in a basket or collander. Barrels can be done inside a piece of 3 in pvc set over a pot of boiling water.

R/O water works too. I get mine for 20 cents a gallon at one of those drive-up kiosks.

I bought a r/o unit for the shop, a great investment! We have as much as we need and no issues with it what so ever. I do enough rust blue that between the cost of the water and the time it takes going to get it, the r/o unit paid for itself in no time.
Steve

Well, it was absolutely the water. I boiled some of the A/C condensation water as recommended above and the red oxide turned jet black almost instantly.

This site is such a great resource for information. Thanks to everyone for the help, once I try it on something more interesting than bar stock I'll post some photos.

Don't you just love it! 20 years ago you would have been SOL! The internet does have it's advantages.

I'm glad to hear that you found the solution. I have found that with our tap water the rust will not turn black no matter the time. With the "correct" water the rust turns dark the instant the part is submerged.

Knowing that the "PCBs"(?) are supposed to leach out of plastic I would think that some distilled water is not totally pure.

quote:

This site is such a great resource for information. Thanks to everyone for the help, once I try it on something more interesting than bar stock I'll post some photos.

Thank you for the question...see, I learned something today. I figured plastic jug water would have been good enough!

Never tried distilled water. I've used "drinking water" from gallon jugs with success. It's just R/O'd tap water in expensive packaging. I bought a 6 gallon plastic water cooler bottle for my trips to the kiosk 6-8 years ago and no problemo.

AC water? Let's see I bet I could get a gallon or two per summer here in Colorado.

quote:

Originally posted by ramrod340:
AC water? Let's see I bet I could get a gallon or two per summer here in Colorado.

The good news is that I can probbaly "make" a gallon per hour where I live.

Change your water
I Don't used distilled.

Glad that you've solved your problem, which can get awfully frustrating trying to chase down at times.
Here's a tip which may be of help to a few. I've had problems in the past with rust-bluing the BRNO ZP-47 & 49 shotgun receivers. The problem is that you sometimes get three different colours, one on the receiver, a different shade on the lockplates, and a much blacker shade on the trigger plate, top lever, etc. I'm in the process of building myself another double rifle on a 16 gauge BRNO and just finished bluing about a week ago. After thouroughly de-greasing, I etched all of the parts in ferric chloride solution for about 5 minutes, then scrubbed everything well in Formula 409 cleaner and HOT water. Then I went straight to bluing. Every piece came out the very same dark black hue, no colour variations at all. Thought this might help somebody out.

On the ferric chloride, full strength or diluted? I've used the Radio shack version when doing Damascus and twist shotgun barrels, but always diluted it.

Straight out of the bottle.

Great thread & thanks! I plan to start doing some rust bluing. I even made up some of my own solution with HCL, steel wool & Nitric Acid. But I am told that the solution is not stable for long. So I may need to make up more.

I have a de-humidifyer at home and we get more than a gallon of water each day. Good to know that it works!

I had problems before I had the tank nickle plated.
We used distilled water by the 5 gallon jugs.

Your solution is effective but short lived. You are making "aqua regia" and ferric chloride. It has to be used fresh. React the steel wool with the HCL first, adding steel wool until the acid is exhausted. You should then have a pretty good solution of ferric chloride. Strain through a coffee filter. Then add a fluid ounce to 2 ounces of 10% nitric acid and distilled water. Throw in a shot of 180 proof spirits to top off to 4 oz. and go rust blue.

quote:

Originally posted by Nakihunter:
Great thread & thanks! I plan to start doing some rust bluing. I even made up some of my own solution with HCL, steel wool & Nitric Acid. But I am told that the solution is not stable for long. So I may need to make up more.

I have a de-humidifyer at home and we get more than a gallon of water each day. Good to know that it works!