doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Discusion on Slow Rust Bluing

I know this subject has been beaten like a dead horse.Covered time and time again.But some of us that are hobbiest need the input.Its hard to find anything on the net or in books that covers all the angles.I know most of the pros here have learned from years of doing,but i am a hobbiest .I might only blue three or four guns a year.I only want to work on my guns,but i want them to be the best that i can do.Its not that i am cheap and don't want to pay to have it done.I really love the the work.I get real pleasure from spending time in my shop working on the rifles and shotguns that chose to rework.Its a labor of love.The pay off is when i finish ,and the gun looks as good or better then the day it left the factory.I know there is no substitution for time and practice .I just want to try to not make as many mistakes as i can. Anyway i don't mean to rant.
Lets talk rust bluing.below are a list of questions and comments that i put together.
1.polishing,what grit is best,and when you get to that grit should it be shined to a mirror.(what i mean is what you get when you keep polishing with that paper until its wore out.a shinny look.)
2.solution.What is the best to use.This is a really hard subject.many like to make there own ,and some like what they can buy.Also on this subject.should you cut the solution for better results.
3.Should you use a hot box.If so what temp and humidity is best.Also what amount of time is best in the box.(i have had some problems in the box with it sweating,and leaving small drop marks)
4.application.what is the best way to apply the rust solution.as well as the amount.I have had problems with this in the past with putting to much on and having it bite to deep into my surface.(pitting it to much)
5. boiling time.I have read anywhere from 10 to 30 minutes.Some have said no less than 30 minutes.One manufactures said ten minutes will work.
6.Carding.I use a carding wheel.Some say to only us steel wool,or scotchbrite.what is the best.
7.Number of coats.What are you looking for.how do you know you have done applied the rite number.
8.oiling.after the last boiling and carding.should the part be aloud to rest.(one smith lets his parts rest for 24 hours)How long before oil is applied.What is the best oil to uses.I have read some uses grease.Can it be used.

This is a list of things that came to mind.I know a lot of this is open to interpretation.What i would like is to find a system that works and gives the best results time and time again.

Just had this discussion with Ken Hurst a few nights ago. Maybe he will bestow his pearls of wisdom again here for you. I learned a lot that night.

Your starting statement is mine except I only work on sxs that are mine, and like you I like doing it. Found out the rust bluing is not hard, the prep is the hardest.
For your first question, I start out with 220 grit emery cloth, if there was a lot of pitting maybe I would use 180 grit. Work my way down to 320 and on the last phase I only go in one direction and do not stop until end. I've also heard that you should use a block of wood. Next time I will. If there are any dents they should be taken care of first. I made up various tapered steel plugs 1 1/2" long and at other end it is bore size (.001 under) with a 1/4-20 threaded hole to hold plug. Lightly heat barrel with propane Bernzomatic and on plug you could use some high temperature grease. I lightly tap area with a small brass or plastic mallet until I can slide plug past area. On some Damascus barels with small dings you can sometimes tap plug and it will come out.
2. I use Laurel Mountain Forge Browner & Degresser. I find it works very well. On the Damascus barrels I use Radio Shacks printed circuit board etchant.
3. I made a plywood steam box to fit barrels up to 32" long and with wooden plugs in each end to hold them up during rusting. I put a small container of hot water (microwave) and let them sit for 3-4 hrs.(summer, haven't tried any in winter)
4. Follow the instruction on the bottle from Laurel Mountain Forge.
5. I boil for 5 minutes.
6. They (LMP) recommends to use demium or burlap. I use 0000 steel wool. Some use 0 steel wool,I think that is to harsh and you will scratch barrels in my opinion. I have never used a wire wheel but the experts do.
7. The amount of coats is up to you. I have done a few barrels wilth 5 coats and I think they look good.
8. They should rest for a while, a day, and then I heat the barrels with a torch and liberally apply motor oil, barrels shuld be warm to the touch but not burn you. Let sit and thoroughly wipe off, sit back and admire your work.

Most of the information here was from members that shared their knowledge.

1897 Grade 3 L.C. Smith. before and after.


Iver Johnson Hercules 16 ga.


Good luck and let us know how you make out.

I'm certainly no professional rust bluer, just a serious hobbyist, but my method seems to work pretty well on the few guns I have done. There is a lot of BS and exaggeration circulating among hobbyists and gunsmiths. I tried to approach it from a scientific viewpoint. Because it is a simple process with simple components, there is not too much you can do to screw it up as long as you observe a few basic requirenents.

1. I never go beyond 320 grit (silicon carbide) used dry and as it wears, it will produce a higher gloss.

2. I have always used Laurel Mtn Forge Barrel Brown and Degreaser. The only gun of the 7 or 8 I have blued that it didn't work well on was the frame of a Nazi P-38. On the same gun, the barrel and slide were perfect. I use it because it was formulated by a pro and it contains a detergent which allows bare-handing the gun parts during coating, boiling and carding. No gloves, tongs or worries about skin oil contamination.

3. I use a damp box based on the one shown in Gunsmithing Tips and Projects ( Wolfe Publishing, out of print) because I have an air-conditioned shop and live in a dry climate as well. I usually run it about 80% humidity and 90°F. The solution is not too sensitive to the conditions as long as the humidity is at least 70%. Rusting time varies somewhat with the steel alloy. Mild steel like a shotgun barrel usually takes about 4 hours to look right while a 4140 rifle receiver might take 6 hrs. After a while you get a feel for the time needed.

4. I apply the solution sparingly with a dampened cloth pad. Too little is not a problem. Too much can cause pitting. 100% coverage is important.

5. I boil for about 10 min. I experimented early on with longer times up to 30 min. and could see no benefit.

6. I card with a 6" DIA. carding wheel running about 500 RPM where possible. Brownells sells some small brushes on wire shanks that can be run inside trigger guards and the like. 4/0 steel wool and SS tooth brushes(used gently) work in tight spots.

7. Number of coats varies with the steel alloy. Shotgun barrels usually start looking good after 4 coats. Modern rifle receivers and barrels might take 6. More rarely does any good and if you don't like the look, repolish and start over. The natural tendency is to run one more coat just to be sure.

8. I could never see any benefit to delaying the oiling after the last carding. Iron oxide is a stable compound and I don't believe in the "let it cure overnight" cautions I have read. I always use whatever gun oil I have handy which is usually Breakfree CLP. Oil is pretty much oil and I doubt it matters at all. I have heard of grease and even linseed oil being used. I suspect the main benefit is the temporary higher gloss they provide.



OB

JDW and OB are right on. I am also a hobbyist and do my own barrels. They look good and professional:Below are my comments:
1.polishing,what grit is best- I use 220 if the bbls are slightly rough and then finish with 320.

2.solution. I use Baker's Modified per the Baker Gunsmithing book

3.Should you use a hot box.No- I get good rusting without it.
4.application. Small foam brush

6.Carding.Fine steel Wool
7.Number of coats.8-10 Usually
8.oiling. Neutralize with Baking soda in water and then I use G96, or something similar

I'm about like all the rest so far as experience goes. I'll throw in my two bits because I do things a little different.

1. I polish to at least 600 grit. 800-1000 if it makes me feel better. I have done two barrels to less than that, and I am very very unhappy with them and will probably do them over one day. I like a shinier barrel, though they, in no way, shine like a hot-dip blue.

2. I will sometimes dilute my rust solution. I do not use Laurel Mt but I hear it is very agressive. I like something slow to match my schedule.

3. My schedule is such that I can usually do a boil in the morning before work and in the evening around dinner. Roughly 12 hrs apart. Because I don't want to risk pitting and because I like a better shine to my barrels than the "matte" look that some love and I hate, I do NOT use a hot box or raise the humidity. This works just fine in the dead of winter when humidity is unmeasurable, and in the summer when it is quite high. My basement or shop are both quite cool, which also slows the process.

4. I apply with a small BARELY DAMP cotton pad. The BARELY DAMP part is important for etching that very well polished barrel.

5. I plug my barrels with expandable neoprene plugs from the hardware store.

This works for me.

Brent

1. 320 to 400 grit for most applications. Higher polish with rusting times and carding material adjusted to keep higher polish in tact. A final quick polish with fine scotch brite (maroon or white) will put a nice look on the barrels and remove the grit lines from the paper.
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2.Laurel Mountain for slow rust. No damp box used. Winter time I still just let them hang and rust naturally, though they will take about 24hr to rust. I recoat the first layer with a second with no boiling/carding to the first after about 12hr to get it going. After that, no second coating.
For hot rust blueing I use Mark Lee solution. I used to use all the older ones but they contained mecury (and worked wonderfully by the way!). Even the old formula Birchwood Casey Quick Barrel Brown was a fantastic hot rust blue because of it's mercury bichloride. It's been reformulated too. The 'new' old Herters Belgian Blue formula from Brownells suprisingly to me seems to have the merc still in it, doing a test on warm brass, so I've stayed away from that also. I shake enough already.
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3.No rusting box
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4. Application slow rust soln with a small pad of old T-shirt material. Just enough to wet the surface. It should be dry or starting to dry at one end of the barrel by the time you are at the other end of an application stroke. Never try to touch up a spot that is already gone over. If there is a small sliver of space that is missed, it will be coated in the next pass. To try and catch it by recoating now will result in a spot in the blue in most cases. Hot rust blueing I apply to first couple of coats with a small pad of degreased steel wool. Seems to get it to bite into the surface better and get a more even coat started. Tough on the fingers!!, it gets hot and your fingers look like a chain smoker when finished, but gloves don't make it for me when doing this. The last few coats of hot rust soln I use a small 'acid brush'.
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5.Boiling time for slow rust is about 10 minutes. For hot rust depending on how many parts I'm juggleing at one time through the process perhaps a bit more.
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6. Carding wheel run at approx 500rpm I think! Keep it clean! and straighten out the wires once in a while by combing a stiff wire brush through it. Light steady even pressure. Avoid 'going after' a spot and using some heavier pressure to remove the coating if it is stubborn or in a spot that is hard to reach. Even a .003/.005" wire wheel can mark up the surface through the new blueing. They don't call them 'scratch' wheels for nothing. I do use some steel wool for small spots but really do dislike the stuff. Degrease it with dishwashing soap while still in pad form first, rinse well, then unfold and lay out on the tank cover while the water heats up to dry it out.
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7. # of coats depends on the steel. Older guns require less to get the color you may want. Newer steel don't often blue well with hot rust blueing, or sometimes with certain slow rust solutions either. Sometimes you have to experiment a bit to find one that works well. A light acid etch to the surface to start can help a problem barrel or a case hardened part (03 Sprfld action) at the expense of loosing some gloss. 4 or 5 coats of blue on most older barrels seems normal. 8+ on some of the newer stuff that says I don't like to be rust blued. Very dilute circut board etchant works good instead of acid for an preblueing etch too. Don't overdue and plug the bores for the etching part. I never plug the bore while blueing and have never had a problem.
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8. I heat the double bbl sets back up with a torch carefully to get any water out from between the ribs. Once cooled down to just warm to the touch I coat with linseed oil. Other parts dry of their own heat and get linseed also. I've always used linseed. Just seemed to be a good thing instead of gun oil that was made to loosen and remove rust which is what I just spent so much time producing and applying. I don't always use the 'let it set for a day' thing, but I used to do that and still do on occasion. Sure doesn't seem to hurt anything. Afterrust can be a problem with some solutions. Laurel Mountain is one in my experience. It does have Ferric chloride in it I'm told so that may be why it wants to continue to rust. A room temp bath in a bakingsoda soln followed again by a rinse helps. A light carding with 0000 steel wool lubed with linseed oil a couple of days after the blueing is completed also helps and also brings up a nice gloss on the blue. I think it removes a top layer of after rust and evens out the surface nicely.
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40+ years of rust blueing

If one were to dilute the Laurel Mountain, by how much would you dilute it.

1) 320
2) black brown (sheffield formula)
some other potions better left not discussed!
3) i sometimes use a sweat box in winter
4) i cut up foam brushes in small pieces - because the whole brush soaks up too much soultion.
5) 10 min.
6) fine wool and sometimes scotch brite
7) whatever it takes to get a good finish
8) any gun oil

kutter,you said you use linseed oil.as in what we do stocks in.wouldnt that harden on you,like it does the stocks