Rust Bluing Problems - Spots and streaks in finish after carding

[JWalker]

Hey everybody, I've been reading articles on this forum for a while but just registered. I was planning on posting some of my recent gun refinishing projects as a first post but am having some trouble on the current project.

I am working on bluing a Winchester Mod 70 barrel using a slow rust blue method. Here's the basic method for this project:

-Removed old blue, polished barrel down to 400 grit.
-Degreased by boiling in washing soda solution, then wiping with solvent (paint thinner).
-Applied Brownells Classic Rust Blue Solution diluted with water 1:1.
-Let rust in humidity box until a uniform red coating of rust appears.
-Boiled in distilled water for 10 minutes, then card using 0000 steel wool and clean with solvent.

I am on my 14th (yes 14th!) cycle of this and cannot seem to get a uniform finish. I achieved the color I wanted after 6 or 7 cycles and since have just been trying to get a cycle that comes out without any blemishes. I am having a couple problems. Sometimes I get a uniform color except for a few spots that have streaks that are darker than the rest of the barrel. When I go another rust/boil cycle, these streaks disappear, but sometimes new ones appear in different spots. It almost looks like as if someone took a blue sharpy and drew a line on the barrel. I tried to get some pics but you can't see much of anything in them.

The second problem is that occasionally after carding the finish will be blotchy, even though it was uniform before. After another cycle it will sometimes go away but other blemishes appear. What causes this uneven finish?

This is not my first attempt at rust bluing, I have had successful attempts before, though I am by no means an expert. This method is the same as the previous project I finished, which I had some similar issues, but was able to get it to come out nicely. I don't think it is an issue with metal prep, degreasing, or cleanliness as it has worked for me in the past.
Thanks in advance for any suggestions.

[Hannibal]

The first question that comes to mind is water quality. I presume you have read the recommendations by Waksupi to use a boiling chamber and stand pipe, thereby steam alone for your rust conversion . . . ? I've not had the opportunity to try this method, but that's what I plan to do when I get 'there'.

Or have I mis-understood and this is a slow-rust brown finish?

Sometimes I wonder if we're not obsessing over details that were not even considered by 'period' rifle makers. (?)

And I'd add that by the 14th cycle, you are FAR past the treatment stage and well into the aesthetics stage. But I presume you are well aware of that. Not trying to be a smart aleck, just pointing out that this is akin to sanding a 'final finish' and re-spraying at this point. And has been for some time now.

[largom]

I would also question your water quality. Might try some distilled water.

[Hannibal]

To the OP - can you post an image or 5?

A picture is worth 1,000 words.

[JWalker]

First, thanks for the quick replies.

I am using distilled water, I use rainwater when I can get it and it seems to work ok too. I've already made the mistake of trying tap water (which is pretty bad where I live) and has seen what can happen.
Hannibal, I have read about the steaming procedure and was planning on trying it on my next project but was hoping to finish this one with the setup I have. Your right though, water quality issues would be a non-issue then.

I know I'm past the point of getting a good protective finish on it, just needs to look ok now. The last 6 or 7 boils have been trying to reach an aesthetic finish I'm happy with. I boiled again and the blotchiness has all but disappeared, but there are still a few darn streaks in it. I took some photos but you just can't really see anything in them. I will try again tomorrow to get some picture worth posting.

[JWalker]

Also, Hannibal, I wonder the same thing. Do you really think back in the day that every smith had all these strict requirements we try to follow for things like metal prep and water quality, and boiling tanks, ect. Sure maybe the factories, but the average gunsmith? Also makes me wonder because the first time I ever tried this I used tap water (in Oklahoma which isn't great either) and it came out beautifully with no problems.

[MostlyLeverGuns]

Have you de-greased the steel wool you are using before rubbing the finish? Most steel wool has protective oil on it. This oil can rub off onto your finish and cause streaking.

[Hannibal]

Ok, well, you may be expecting too much. Slow rust bluing is FANTASTIC for preserving steel, but not so good at making hearts go 'pitter-patter.' Savvy?

You might be asking too much of the process. Photographs would help to determine that.

[kens]

My first question is about the 'solvent' wipe.
Example:
if you polish it down to 400 grit, then you BOIL it in DISTILLED water (at that point you have a sterile gun): then you "solvent" wipe it;
then that concerns me that your 'solvent' has dispersed impurities from your rag, your hands, or from your bench.
My main question is about the purity of your wiping rags;
since you posted that you boiled in distilled water, then at that point you are 'sterile';
only after the boiling can you become contaminated, such as the 'solvent' wipes.

[LAGS]

I saw something in your post.
you said you wiped it down with Paint Thinner ?
Paint thinner does have some sort of oil in it, same as steel wool.
I strictly use Acetone for the final Degreasing /Drying and wipe down.
I also use it to clean the steel wool with Acetone before it ever touches the metal on my Gloves.
Also De-grease your carding brush.
Most of my Slow rust bluing is done with Pilkingtons straight out of the bottle.
It has been a while since I have used the Brownell's, and don't remember having to dilute it.
Water Quality is way at the bottom of my list of suspects with your situation, especially since you are using Distilled water.
I suspect some kind of contamination like Oil on your gloves or improper cleaning.
I also always Bead blast or sand blast my metal before I try to do the slow rust bluing.
Slow rust bluing does not like Slick Polished finishes.
It ends up like putting water on Glass
Also, are you Wiping the Bluing on with a Wrung out clean cotton Ball, one pass, and one direction.
Damp, Not Wet
The rust bluing should almost dry on the metal Instantly.
If you wipe it on with too much Liquid on the cotton, and wipe it in with several strokes, you are removing the bluing you already put on from a previous cycle.
Rust Bluing, removes Bluing.
I only had one rifle that started streaking and spotting.
I called the instructor from my Bluing Class from years before, and he asked if I had Bead blasted the metal.
I told him No, I Polished out the metal really nice to try to get a shinier finish.
It was like a Mirror.
After I bead blasted the receiver, problem was solved.
But a 400 grit sandpaper polish where it still is a little rough works too.
90% of my rifles only get 6 cycles of rusting to get a really nice finish.

[Hannibal]

An over-polished finish is most definitely not good. However, the OP said they stopped at 400 grit, which -should- be OK so long as the OP didn't sand on it excessively, resulting in a significantly finer grit abrasive.

The prospect of oil contamination via the solvent is a good one. I've seen people brag about using lighter fluid to degrease before applying Loctite.
Tony Boyer recommends using lighter fluid as a lubricant. Jewell triggers on benchrest rifles. You wanna tell that guy he's full of ****? Go ahead. I'll take his advice.
So. The point being, let's assume petroleum based solvents will leave an oil residue and move forward from there, shall we?

And I suspect Mineral Spirits, AKA paint thinner, is going to leave MUCH more oil contamination than lighter fluid.

Just a thought, OP.

[LAGS]

One thing I learned in the slow rust bluing class but I seem to be the only one who mentions doing it.
On my Last Rusting and Boiling, I do not Dry Card off the metal.
I take light machine oil like 3 in one, and a clean rag, and wipe down all surfaces and leave it WET.
I let it Cure overnight, then the next day, wipe off all the Black Muck with a soft cotton rag.
My finish comes out a little darker, and the oil really protects the finish.
Hay, it works for me.

[waksupi]

A big mistake people make in rust bluing, is in the initial rust process. If you are using a sweat box, and see any signs of condensation or beading on the metal, you are going to get a lousy looking barrel. Too much moisture. Those water beads and streaks will show up in the final product.
Don't wait for a heavy consistent rust over all of the barrel. When I do them, the rust is barely apparent before steaming. It seems counterproductive, but it works. You get a much higher quality smooth bluing job doing it that way. I can run metal through the process around a half dozen times for an excellent blue.

And don't polish past 320 grit.

Boil out times required are 25 minutes. Steaming time, 20 minutes.

This Trapdoor was done with six cycles, steam method.

http://castboolits.gunloads.com/show...-rebirth/page2

[JWalker]

I do not degrease the steel wool. I do use a new piece every time though. This is the reason I wipe with solvent after carding. My reasoning is that cleaning after carding will get rid of contamination from the steel wool, as well as any from gloves, workbench, anything else after boiling. It has worked for me in the past. The streaks are there before degreasing so it is possible the steel wool is leaving something, but it would be odd that it would not then wipe off with solvent, as well as how few streaks are actually left. Your right though, it is worth a try to rule out the steel wool as a problem.

[JWalker]

New piece of fresh cotton every time, for solvent and bluing application.

[JWalker]

LAGS: Contamination from the thinner is something I have not thought about. I used it because when I was first learning this process money was tight and that is what I had for other things and that seemed to work. Maybe I was just lucky that first time. I will go get some acetone for my next cycle and degrease the steel wool as well. The streaks appear after carding before wiping with the thinner, but it may impart something that then messes with the subsequent rust and boil. Letting the last cycle "cure" overnight is interesting and something I will have to try.

waksupi: I try to boil as soon as I get a fine red fuzz, however due to time this doesn't always happen. Building a steamer instead of boiling is also on my to do list for the next project.

[LAGS]

@ Jwalker.
You may have got lucky with the Paint thinner on the first ones.
See, Paint thinner has solvents in it that evaporate when left exposed to air.
Those solvents evaporate as you leave the can open.
Then near the end of that can of thinner there will be more of the less volatile solvents , ( The oil Base )
A simple test.
Pour equal amounts in three clean containers say one ounce each of, Paint thinner, Lacquer thinner and Acetone.
Let them sit for a day or two and see which one evaporates first, and which one leaves a residue in the container.

Now, my Steam Cabinet is the Spare Shower .
I am single ,so I can hang my parts in the spare bathroom and turn on the shower till the room gets steamy, then shut down the shower.
That may be changing since my Girlfriend moved in.
Then just let the parts rust overnight.
But don't forget and leave the shower running, or you will get condensation on the metal, and runs in your rust.
Also,
Using Un - Degreased steel wool, you are working that oil on the steel wool INTO your Bluing.
Wiping it off even with solvent like acetone will not get it totally clean.
When I teach someone how to do Slow rust bluing, the first thing I teach them is.
Before you put on your Nitrate or Latex gloves, Scratch Your Nose.
Because every time you put on your gloves, your nose will itch for some reason.
No one thinks about then scratching their nose with their Clean Gloved Hand.
But then you just put Skin Oil on your clean glove.
Same with picking up anything with your gloved hand during your handling of the metal.
I keep a towel dampened with clean Acetone on hand to wipe off my gloves or to set or rest the metal parts against on the bench.

[Stockcarver]

1. No paint solvent. Use acetone.

2. DeOil your steel wool, it is full of oil.

3. Distilled water.

4. Don't touch the metal with your fingers!

5. Why are you diluting the solution with water?

6. Put on a light even coat, do not go back and re apply. Work in one direction, i,e., right to left.

7. Buy the Brownells fine stainless steel wire carding wheel and run it slow. One of my grinders is variable speed, the carding wheel goes on this one. I do not use steel wool for carding, too many problems.

8. Only use the cotton swab once, do not re dip it in the solution. Dip, apply a light coat of solution, throw the swab in the trash, grab another new one.

I live in the damp Pacific Northwest, 2 miles from salt water, and a "rain forest". I just hang the parts on the carport, the atmosphere is perfect for rust bluing.

9. Read and re read the Brownells instructions. Pay attention!

10. Washing soda has oils and fat in it. Buy proper cleaner from Brownells.

11. I pour a small amount of solution in a watch glass or custard cup. Never pour it back in the bottle! Toss the unused amount.

[pietro]

I will go get some acetone for my next cycle and degrease the steel wool as well.

Welcome aboard !

With all due respect, FORGET about a "next" cycle.......... IMO you'll be adding insult to injury with additional applications.

Whatever's wrong is already in the steel, and all the previous bluing needs be removed with vinegar (?) and the bluing started over from scratch (I would go, using LAGS & stockcarver's tips, above).



In any event, I hope all here have a very HAPPY NEW YEAR ! !



.

[JWalker]

1. Got some acetone this morning. Will use that from now on.
2. Just deoiled some steel wool.
3 and 4 I have been doing.
5. I read a few people say that to achieve a higher polish finish with rust blue you can dilute the solution on subsequent cycles so that you get less aggressive rusting. Its something I have been experimenting with.
6. Done
7. On my list but the only grinder I have is a homemade one and not variable speed. This will have top wait but hopefully will have it before too much longer.
8. Done
9. Done. Done. and Will do again.
10. Some older texts I have read on bluing suggested washing soda. It is possible that washing soda back in the day was more pure or "clean". I will look into this.
11. Done.

Most of this I try to follow already. I'm in dry West Texas so a rusting cabinet is necessary. This is a good list of reminders though.