doublegunshop.com - home Forums General Discussion DIY Gunsmithing @ doublegunshop.com Speaking of Rust Bluing....

Getting back into the shop after a too long hiatus (Partly while building the shop ...)

I'm prepping barrels for rust blueing, and I've got a few questions about managing the water exposure:

Primarily, I'm wondering how to keep water out of the rib space? The front bead hole and a weep hole (not sure what it's actually called) both seem to communicate with the space between the barrels. (Pics)

I'm also interested in what you all think about plugging the barrels vs leaving the open for the boiling?

Leave them open.
That's the only way that any water that may get inside the ribs will be able to get out.
Though it may seem strange to poke holes in the ribs to purposely allow water in in the first place, it's a fact that most all bbl assemblys have at least a small area
of leakage along the feet of soldered seam of rib and bbl.
It's a rarity that there is absolutely no break in the soldered joint anywhere.

If the drain/weep holes are not there, that water that does get in there by those small voids, and it will,, will not smoothly exit the assembly as you are bluing.

It will start to seep out of one of those small cracks or voids as the water builds up inside and you handle the assembly after taking it out of the water.
Then that crappy water from inside the ribs leaks over the new blue and spoils the finish.

With the drain holes, you can hold and tip the bbl assembly as you pull it from the tank and let the water drain out w/o running all over the new finish.

Plus after the last cycle, put the bbls on a stout peg in one of the chambers and mount the assembly nearly upright.
Let the muzzle tip forward a little and the bottom of the bbls where the rear drain hole is will be in position to allow any water still inside to drain out and down the hole that the extractor shaft
sits in.
At this point take a propane torch and carefully warm the entire assembly to dry up any trapped water.
You will see the steam start to chug out the front and rear drain holes as well as extra water 'spit' from the rear/lower one.
Keep a paper towel handy to clean up any that comes out.
Keep the heat up untill you are satisfied that it's dry inside there.

Do not over heat as you can melt the soft solder. But you have to get to 400F+/- to do that.
If you are getting close to that you will hear the bbls start to make a creaking noise. That's the metal expanding.
You only need 212F to boil out the water.

Let it cool on it's own when done.

That's what I do anyway.
Others have different ways and it's the final results that count.
The worst thing is to have a completed, finished & assembled gun in hand and have some water leak out from betw the ribs.
I've seen that many times.

I know there must be many who appreciate your thoughtful and detailed responses, Jim.

Thank you again. Stan

Count me in the list of ones who very much appreciate the sharing of knowledge that has been gained through years of experience

And me as well. I've not blued double yet, but I have one to do.

kutter, would a heat gun work as well or better than a torch? Might it be easier to control heat perhaps, at least for those of us with less practice?

As cutter said, others do it a different way, and some make an effort to repair the solder joints. When the water is allowed to come out, it will also go in during use. The main reason for ribs coming loose is rust at the inside of the joint and allowing water to enter only makes it worse. Where leakage was only discovered late in the process or was minor, I have seen a string "worried" between the ribs (with a scribe and compressed air) and "Ballistol" added to prevent or at least slow rust forming. I have been informed that in the old days the entire (or most) barrel blank was "tinned" before soldering the ribs on to avoid rust under them. Cleaning the barrels for bluing after extensive "tinning" was difficult and this process was slowly eliminated. When repairing small leaks, I noted the use of an electric soldering iron to place the heat directly at the joint, but with additional heat applied to tip with a torch and the ribs wired down on both ends of the leak to prevent more leaks.
Mike

In days past when I did Instant Rust Bluing having a 3 day turn round, on the final clean water boiling I would hang he barrels up to steam dry to keep the heat up in the barrels I used a gas torch but as mentioned a heat gun today would work very well. When the barrels stopped steaming I would put them in a final tank completely submerged in Water displacement oil. This would guarantee as far as possible no water in the rib cavities or anywhere for that matter on a set of barrels. Over time I was never able to find anything better where I could give a guarantee on no water under the ribs.

I agree with everything Kutter said. A set of 28" barrels will have at least 116" of solder joints along both barrels for the top and bottom ribs. I learned long ago that it is common to have one or more areas that either were not perfectly soldered during manufacture, or became separated at some point. So the problem of contaminants getting into the voids between the ribs and barrels may have been going on for decades. It is possible or even likely that gun oils, barrel cleaning solvents, grime, and rain has gotten in there over time. Getting any of that garbage sufficiently cleaned out and neutralized before starting the rusting cycles is just part of the job. And despite your best efforts, it is possible that something will leak or creep out after one of the boiling cycles. So after you have done the best you can, making sure that hidden void is totally dry is important before doing the next application of rusting solution. Kutter uses a propane torch. I use the same burner that is used for my boiling tank. I pass them back and forth over a low burner flame to heat them as evenly as possible (to avoid differential heating and expansion). Just getting them hot enough that they are uncomfortable to hold is hot enough to vaporize and dry out any moisture in there. There is no need to get them anywhere near hot enough to worry about melting the rib solder joints. Some instructions advise drilling weep holes where none are present to facilitate this, but I haven't needed to do so. I have to wonder if Kutter is shaking his head over the Professor's question of whether a heat gun could be used instead of a propane torch!!!But both will contribute to Global Warming, so that might keep some folks awake at night.

It is important to look for any areas that may have leaks during the cleaning process done after old blue removal and prep. There may even be existing weep holes, and there will be a hole present if the front bead is removed. My first cleanings are done with Dawn Dish soap, and then I immerse the barrels in a hot lye solution to remove any traces of oil or grease. Then they are thoroughly rinsed and dried. While in the hot water, I look carefully for any small stream of air bubbles that would indicate leaks that may cause problems later. In the event that anything does creep out during the rusting cycles, I can usually control it by spot cleaning the area with degreased 0000 steel wool and denatured alcohol. This prevents spotting, streaking, or uneven areas.

When all rusting, boiling, carding, and/or etching cycles are finished. Everything needs to be cleaned, neutralized, and rinsed again, which means more moisture in this void has to be dried out. After the blue is well cured, it won't hurt to get some thin oil, Ballistol, or corrosion inhibitor in there to prevent future rusting. An existing weep hole makes this easy to do with a syringe. Of course, all excess oil must be drained out so it doesn't leak later and oil the stock wood. I've also read that some barrel joiners tinned the entire tube assembly before soldering, but it's hard to believe anyone in their right mind would do it more than once. It would just waste tin and flux, and create a lot of extra work removing the excess tin before bluing. The area between the barrels may have been sufficiently tinned to prevent corrosion, but it isn't possible to know for sure. Attempting to repair a small area of lifted or imperfect rib solder joint can be problematic. Soldering is very easy when you have a perfectly cleaned and tinned joint, the correct solder, temperature, and flux. The only rib repair I have done was fairly easy because it was loose at the muzzles, and I was able to get some very thin abrasive paper in there to clean the joint without removing the original tinning. I then flushed it with electrical contact cleaner to remove any contaminants. Trying to clean and repair a contaminated and imperfect joint can cause a frustrating mess of things, with much swearing and gobs of solder rolling off and onto the shop floor.

damascus,
The procedure I was talking about was the slow rust process and would only use oil to "cure"(darken) the color, as the very last step and that would not be water displacing oil (WD40), for fear of removing some of the rust. After curing, water displacing oil wouldn't hurt.
Mike

Mike-- sorry I'm a little slow on the uptake here, but would you clarify what you are so describing? Are you saying that you look for water or steam leaks along the ribs and then re-solder any spots that aren't water tight? And then would you try to seal up the weep hole and front bead hole before rust Bluing?

Ernie-- Do you worry about how much wd-40 (or equivalent) would remain between the barrels after the soak?

Thanks all for the input. As with many things, it seems there were multiple ways to skin the proverbial cat.

Here's a follow-up / add on question: when polishing the barrels in preparation, what do you all do about the 'hard to reach" areas, like the nooks and crannies along the lumps, ribs, etc? It seems inevitable that some areas will remain less polished or even untouched.

The only things that gets blued that I do not polish is rib mating, I use a fine wire wheel for that. Everything else gets polished in line with the bore using backers of various types, I usually stop at 400 grit, I will go higher if I want a high luster blue.

These are great: https://www.amazon.com/Polishing-Woodworkers-Automotive-Sandpaper-Woodworking/dp/B086YXR9RH?th=1

Also hobby polishing sticks from Steve's Hobby(I'm in no way affiliated )


Tongue depressors with abrasive paper stuck to them are handy as well.

As a final step to my polish I run the barrels over a carding wheel(I card by hand) and the wheel homogenizes the finish nicely removing any trace your polish paper has left behind. When Nitre bluing I use a similar process but buff on a felt wheel with fine compound right before heating the part you are going to color.

Thanks Steve. That makes sense, and those contoured sanding blocks look like they will be a great help.

(you also answered another question I had-- many things I've read say stop at 320 grit, but I have had the impression that a finer grit polish would (take more time and) produce finer results, assuming you like a relatively high luster).

Yes, but high luster rust blue is very tricky and requires more than a higher degree of polish. You cannot let the acid work on the metal too aggressively. Environment is very important. I find a rust box too intense if I want a high luster blue. Strength of the solution, humidity, temp, and time all come into play and there is very little margin for error. More input from our British friends would be greatly welcome. I had it worked out nicely with Pilkinton's in my last shop and my current one, it is no longer produced and I am working towards similar results with a batch of Brownell's that I have. I really need to make my own, I do making my own browning solutions.

Woodreaux,
As noted above, I believe damascus and I use different processes to blue the barrels. I use the slow rust or cold rust process with a German solution. I clean the polished barrels with acetone and after cleaning am careful to avoid touching the barrels with my skin. I apply the solution with fine steel wool (also cleaned with acetone) dipped into a small amount in the cap of the bottle. After evenly covering the barrel, pour any leftover solution out of the cap, but not back into the bottle. Then put the barrels aside to rust. The amount of time for rust to form depends on the temperature, humidity, type steel, and degree of polishing. Since you can't time it, just watch it. The first application will take a while and will be pretty light in color. After a layer of rust forms boil it in plain water to kill the rust, and card the rust off with steel wool cleaned with acetone. I learned to card the rust with a wire wheel in Germany, but I wasn't able to find one here that was fine enough to card without damaging the surface, consequently the steel wool substitute. Boil the barrels long enough to heat the steel so it will dry when removed from the tank and gently shaken. The rust will stop quickly but I usually let the barrels cook 15 minutes. If I don't have time for another cycle, I don't card them until the next day. Never let the barrels rust overnight. They will be ok overnight if boiled but will pit overnight if not boiled. I leave the bead in and if there is a weep hole, I leave it plugged. If water leaks, it will be obvious without looking closely. Rust boil and card as many cycles as necessary until you are satisfied. I polish with worn out 320 grit cloth after 180 and 220 backed with files (mostly Barret or Pilar files or old files ground to fit into close places). The solution I use will work on small areas that couldn't be polished and the color will still be even, and partial areas can be rusted and carded to even out missed areas. When you are satisfied, oil the barrels with regular oil and clean the bores. To finish, polish the barrel flats and side of the locking lugs, the extractor and rear barrel face, as well as the end of the muzzle bright, with worn 320 grit cloth.
I learned to use cleaned steel wool to apply the solution because it may remove any contaminates in the air (oil droplets) that find their way to the surface. This process leaves microscopic pits in the surface and color inside the pits, so it takes extreme wear to remove the color, also extremely fine polishing is not necessary and depending on the hardness of the steel the solution may not "bite" and the part may have to be re-polished with a coarser grit. I don't have experience with the process damascus uses, so I can't answer to it.
Mike

I have done many, many rib repairs. I do not seem to have near the problems you have Karen. Less gobs of solder, more time prepping and the proper heat envelope and the vast majority of time a rib repair can be performed cleanly and successfully.

As always, what a pleasure for you to share the depth of your experience with us.

All my best,
Steve

Der Ami. Rust bluing is exactly what it says. Slow rust bluing is only slow because it takes time for the rust to form. There are rust blue formulas that will rust the metal in seconds or minutes, these mixtures where instant or rapid rust bluing solutions. You do not see these rusting solutions today because of there high toxicity and high cost due to difficulty in obtaining all the constituents. This method of rust bluing had major advantages as far as the gun trade was concerned having extremely fast turnaround and the mixtures could be used to instantly touch up worn blue sections in barrels. I do still have a pint of this rapid solution for my own personal use. I do think that if people are interested in the art of bluing and browning the best investment people can make is purchase a copy of "Firearm Bluing and
Browning " by R,H. Angier an old book but thankfully always being re printed.

damascus,
I understand, but I use the slow process because that is what I learned and cannot address the other processes (Belgian or others). I don't call myself a gunsmith and don't do outside work so turnaround time doesn't mean much to me, anyway I don't stand around waiting for the rusting, I can do something else while waiting. Also, in my opinion (I know what opinions are like) slow rust results in a better finish, if you have a different opinion, I respect it.
Mike

I use both Slow Rust (Cold Rust) bluing and Express Rust (Quick Rust) bluing.
I used to use the Belgian Blue formula (Quick/Express Rust) and some others in that same catagory. They worked great. Mostly due to the mercury compound(s) in them (merc bi-chloride(?).
The old formula Birchwood Casey muzzle loader Bbl Brown was another that worked very well. Also contained Merc BiChloride.
(Their improved formula does not)

After many years of feeling bullet proof from such things as merc poisoning/damage to the nerves, old age finaly rings a bell and tells you maybe there's a different way to go,,just to be safe.
Yes we all played with liquid merc in school 'plating' copper pennys and such and none of us died from it AFAIK.
But the constant exposure and more so the thought of the merc in the carded dust,,on the tools, the floor, all over the shop and myself and clothes told me it's likely not a very good plan for the future. Even if I don't care about just me, how about others around me.

So I went with Mark Lee's Express Blue maybe 25+ yrs ago and am entirely satisfied with that for the Express Rust process.
I admit that I rarely use the Express Rust Blue anymore except on some touch up and hurry up jobs. But it certainly has it's place. Lots of kitchen stove top small jobs, it's great for that.
No merc in it so I am fine with the stuff.

Brownells brought back the old Herter's Belgian Blue a some yrs back and said it was the same orig formula. That old stuff had the mercury bi-chloride in it.
I wondered if the new Browneels formula maybe substituted something for the Mercury.
I bought a small bottle of it and tried the test for merc (swab some on warmed Brass, see if the mercury 'plates' out onto the surface).
It did,,I was surprised. I would have thought that selling a mercury compound soln would be off the table at this point in PC/Greeny time.

For Slow Rust Blue I use Laurel Mtn Forge rust soln. It has bit of nitric acid in it as well as copper sulfate.
I've used a lot of other solns as well,,this one works well and I've stuck with it overcoming it's tendency to after-rust and to
'plate-out' the copper at times when applying.
I used to use Sal-Ammoniac water soln way back. Some chips of the soft solder flux disolved in pain water
Most anything that will cause a fine rust will work.

I try not to let the Slow Rusting cycle build up very much,,just a very faint brown/red color on the surface. No heavy rust coating
I lightly drag my finger tips down the side of the bbls, if I can feel a very slight roughness,,they are ready for the boiling water tank.
You will get a fine layer of color with just a faint rust coating.
No need for the rust coating that looks like an old piece of farm equip left out in a field for a few years.
That just pits the metal and muddys up the water tank.

Kutter,
I was told the German solution I use can also be used to brown barrels by carding without boiling and after the color is satisfactory stop the rusting with oil. I haven't tried it though and don't know the formula. I hope it is not as bad as Agent Orange.
Mike

A good quote from Angier:

"Apart from a few exceptions -- mentioned hereafter -- the appearance of the finished parts corresponds to that of the un- browned surface: highly-polished surface thus retain a brilliant finish, dull ones a correspondingly non-reflecting coating. The mechanical preparation (polishing, etc.) of the pieces thus postulates the necessary attention: the greater the care taken in this respect the better the final result." p. 4-5

Der Ami;

Willi Barthold (Von Ingenieur und Buchsenmachermeister) in his German text book on gunsmithing JAGDWAFFENKUNDE on page 144 quotes his blacking solution in 1 liter of distilled water as:

30 g Eisen (II)-sulfat FeSO4--7 H20
15 g Eisen (II)-chlorid FeCl2-- 4 H2O
12 g Kupfersulfat CuSO4--5 H2O
50 g Alkolhol (absolut)

He says that smaller amounts of the solution can be made by reducing such as 10 percent.

Barthold's blacking solution is the practically the same solution as Angiers quote on page 88 (C.17. Swiss black (Beutel. Is your German solution similar?

I have used Barthold's solution in the past with success. It was also a favorite solution of the late Jack Rowe.

Stephen Howell

bushveld,
Thanks for the information. The solution I use is a commercial product that I brought back from Germany when I moved back. As a commercial product the specific formula would be a trade secret. The next time I go downstairs to my shop I will check the bottle to see if general contents are listed.
Mike

I looked through this entire Thread Stevie, and did not see anyone named Karen who mentioned having the kinds of problems doing rib repairs that you mention. It looks very much like you are once again doing all you can to Troll and to disrupt Woodreaux's thread. Nothing new there. Or maybe you were just hitting the bong a little early today, and didn't comprehend what you were reading.

I did say that I had no problem doing the only loose rib repair I have needed to do so far. Kutter did say that it was a rarity to find barrels with perfect soldering joints, and not have leaks to contend with during bluing. Mike obviously recognized that fluxing and tinning is a necessary part of soldering. I did accurately note that attempting to solder a contaminated joint would result in having solder roll off and not stick. I think most of us have probably seen old guns that had rib or forend lug repairs that looked like gobs of gray bubblegum.

I did have problems with soldering a couple times while doing solder repairs on old dirty truck and tractor radiators. Poor cleaning or fluxing will cause leaks and other problems when soldering pipes and tubing, or anything else. But as anyone who has actually done any amount of soldering knows, once I got the area clean enough and used the right flux, the solder flowed like magic. I tried four different brands of flux before I struck gold when repairing a hole punched in the radiator of my old Ford tractor.

As far as your comment about sharing depth of experience goes, you showed me that you probably don't have much actual experience when you posted that you were doing a 45 second Damascus etching dunk in a 14.5% ferric chloride solution at mid 60's temperature. Those who have actually blued or browned Damascus will immediately be amused by your comment. Others were "surprised" by it and commented on that insane etch dwell time. You later said you were dropping your etch time to under 10 seconds, and cutting the concentration considerably. You revealed a lot about actual "depth of experience" there. Here's your post #76837, and a link to the whole Thread where you changed your story. Too funny, but a lot of people seem to have some pathetic need to act like experts on the internet:


https://www.doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=77129&page=1

I'm still always open to learning more about things like rust bluing, etc. But I also learn a lot about people here. Some just can't be trusted.

Karen,
I found there to be a learning curve when I developed my browning and etching process, what has your experience been?

These days I do not etch much, very little really, and rarely finish damascus as it just does not fit into my shop schedule. On the rare occasion that I do brown barrels, I use a modified browning formula out of Angier's and a 29% Ferric Chloride solution reduced 9:1, not dipped but applied with a brush and washed off immediately.

How do you etch your barrels Peaches?

Did the process you tried the first time end up becoming your final one?

In 2008 I had an apprentice in my shop, great guy, no secret there. Manito Lara was his name and he did outstanding barrel browning, he no longer works for me so after 2014 I had to work out the process on my own. It took a bit to figure out, I can do it but it is usually not worth my time to offer browning services.

One point of correction though Karen, Manito Lara did all of the browning in my shop while he was employed with me, I did and always have done my own rust blue. You are lying in the other thread about me asking Doug to blue for me, never happened, I did not like Doug.

Here is a gun I completely restored, including the browning. That was a great rifle....







A close up of the browning and a bench made front sight, all done in house by me except Charles Lee inlaid the Gold bead.



A set of shotgun barrels that I browned.




If you ever get the courage, I'm sure I'm not the only one who would enjoy seeing the work of an expert such as yourself. Maybe you could take the time and offer us some advice from your extensive experience. Stockbending maybe?

All my best to the biggest princess on the board.
Steve

A handy tool for rib work, tight fitting copper plugs, heat them with acetylene and then insert in the bores. It allows you to put the heat where you want it and keep the flame away from your rosin flux which is flammable.

Back to the OP's original question. After boiling I take a syringe and squirt alcohol in the weep holes, alcohol absorbs water, I do that a few times then squirt LPS 3 in there.

It's a technique.

That makes sense to me. I had wondered about flooding the space with alcohol or acetone or another evaporative solution like that.

I have never used LPS 3, but I guess that is along the lines of the water displacement bath that was mentioned earlier.

Thanks for the input.

I'm not a big fan of WD 40 for metal protection, Its great for machining aluminum, and will cut through dried oil/ grease crud. I suspect It's mostly kerosene with some light oil and stuff to make it smell pretty.

LPS3 is a very light oil (water thin) that is designed for corrosion protection.

On double barrels, I spray carb cleaner in the weep holes, get all that old crap out, followed by boiling in a TSP solution. Barrels then cleaned with greased lightning and Dawn soap.

After that double barrels are boiled in clean water to see how much oil comes off of them, if nothing comes out
Start your rust bluing process, if oil keeps weaping out..start over with TSP boil.

Very informative thread, thanks to all that added to it.
As I stated in the General Discussion, I learned mostly from what Dr. Gaddy had posted many years ago and have used his technique. What I haven't read on here was when leaving the barrels in for rusting and then when ready for etching, what do you put in your barrels for protection? For rusting, I use rubber plugs with 1/4" copper tubing bent 90 degrees so the ends are out of the water, for etching I just use rubber plugs. I tried one time using a shellac coat on the inside of the barrels but too much time getting it out. Like Kutter stated, a weep hole is indispensable and most if not all L.C. Smith's have a weep hole near the loop for drainage.
As for bottom ribs not fully soldered, I don't think I have seen one that was soldered fully. I have taken a .001 narrow feeler gage along the bottom ribs and have had it go under the ribs on both sides in a few places. Rust blueing them doesn't hurt anything but when you etch Damascus barrels I always take them out of the solution the bottom rib is facing up when I rinse them under running water. Learned that the hard way.
I hang them to dry and use a propane torch and get it warm to the touch and then spray Kroil oil in the weep hole and hang the breech end up.

Like I stated in the General Discussion, I only do this for myself, no one to answer to except me.

The one thing that I have to say is that I have seen L.C. Smith's refurbished along with refinished barrels and even some of the top notch people doing the work put a high finish on the barrels, From Field Grade to Deluxe they all had a matte finish. So beware of someone selling one that way that states 90% condition as it is not.

bushveld,
Sorry it took so long to get back to you. The rust bluing solution( Streichbruenierbeize) I use doesn't have any of the chemicals listed. The solution is DEWE BRUENOFIX, 8540Rednitzhembach, Industrgebiet, Telefon (09122) 3760 + 4383. The address and telephone number are from 1981, so they may not be current.
Mike

Do you all remove old bluing with a chemical remover (e.g Brownells steel white) or just with the abrasives used for polishing?

Abrasives myself, I polish with the finest grit I can to get the job done efficiently. I use quite a bit of 240 grit Norton emery cloth to remove bluing and find the 1&1/2" wide to be about right for my needs. Good deals on Ebay at times.

Jim,
I don't remove the old bluing with chemical remover prior to polishing but toyed with the idea of using brick cleaner to do it. However, I decided it would save time to clean it with acetone to remove the oil before polishing as oil residue clogs the abrasive cloth. This is in addition to my post polishing acetone cleaning. I am interested others experience, especially if only "spot polishing" might be enough before bluing.
Mike