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Ted Mooney, P.E. RET
Pine Beach, NJ
The authoritative public forum
for Metal Finishing since 1989
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To Blue or not to blue a gun
Q. My Question is... Does anyone out there have a better way of reblueing a gun. I have included all of the attempts (successful and not so successful) I have made, but I know there must be a yet easier and better way to re-blue a gun that doesn't require me to go buy a can of #5 Black Enamel Paint.
I have been blueing for about 9 months and have tried everything short of using black paint. (Just kidding)
I have read everything there is to read on parkerizing and blueing, and basically it's expensive. If you want to do it right it is anyway..... or if you want to pay someone to do it for you.
My first try was the hand rub method... using Birchwood Casey products. First I degreased the parts, then the rust and blue remover [adv: bluing remover on eBay or Amazon [affil links] finally a good final cleaning on the bench grinder with the steel brush. Then I hand rubbed the Perma-blue Perma Blue [affil links] on and let it cure in gun oil [affil links].
Final product okay (At the time beyond my wildest expectations) by todays standards.. acceptable at best.
Next I tried the dunk method. I still clean the parts the same way, but I actually bought enough blueing solution to fill a little bath and dunk the parts in there and let them sit until the were blued. After which I once again cured them in gun oil.
Final product: better, a tad darker but still not Factory.
Next: The Boil and dunk method. Once again, cleaning the parts, as mentioned above but next I boiled them in a bath of water, epsom salt [affil links] and baking soda [in bulk on eBay or Amazon [affil links] . (This will remove whatever you thought you had removed but was still sticking on it . The Epson salt/Baking soda sets the boiling point a little higher : approx. 225 degrees) Then the same dunk and cure method.
Final result: Nice Dark and deep blueing. When curing the pieces black residue did come off, but I was told this is normal. I am very happy with this blueing, but I am about to try the Copper sulphate/Iron Chloride/Hydrochloric acid/Nitric acid in Water solution. and per the advice of the Local Curio and Relic Gunshop I will cure in WD-40 ⇦this on eBay or Amazon [affil links] this time.
I want you to know I did have to build a couple of baths in PVC to accommodate all this, but I haven't spend the 125 $ I would have if I was to have a gun blued.
One last word of advice.... You will have to look high and low to find Nitric Acid. I actually had a Neighbor (Aspiring Chemist) distill me a 90% pure batch of Nitric Acid.
I will keep you all up to date on how this last blueing turns out but please if anyone has a better way... let me know.
Thanks.
Michel M. Thiran- Tarpon Springs, Florida
A. The reason your blueing isn't looking "factory" is because gun manufacturers use a different type of finishing process. What you are doing is creating a depository coating commonly called "room temp black oxide". Gun manufacturers use "hot black oxide" to finish their products. Hot black oxide involves using boiling caustic (it boils at about 285 °F) and actually turns the steel black. Room temp blackening can be removed with a pencil eraser, whereas hot black is as durable as the steel because it is the steel. The blue color you see is because of the light refraction from the oil finish. My recommendation is to find a plating shop that offers hot black oxide finishing. Most shops have a minimum charge that should be pretty reasonable for a single firearm. Good Luck.
Dan Brewerchemical process supplier - Gurnee, Illinois
A. I've yet to find a good cold blue - i.e., durable - and I've tried a lot of them. Brownells' supposedly has a good cold blue (Oxpho-Blue ⇦this on Brownells or eBay or Amazon [affil links] ) that I've not tried myself. You may want to check their website.
Brownell's also has a line of hot blue compounds that most good gunsmiths use, but again, I have not used them personally, so I can't recommend these. Problem is that hot blue is expensive for a single gun, and you need heated tanks. I'd recommend being happy with whatever cold blue seems to work best, or else bite the bullet and go to a gunsmith that does bluing.
Dennis Kirsch- San Antonio, Texas
A. Michel,
I have used Brownells Oxpho-Blue ⇦this on Brownells or eBay or Amazon [affil links] and although it is good, it is still a cold blue. I do hot bluing and I don't think you will be happy with any cold blue process. It sounds like you have spent a lot of time on this but I think you will do best and be most pleased by finding a good gunsmith in your area who does hot bluing. Make sure you explain if you want a mirror finish when done as this depends on the finish of the metal before it is blued.
Good luck.
Ed Kay- St. Louis, Missouri, USA
A. Bluing success or failure is determined by a number of factors. (1)Metal preparation: the surface quality, shine, polish or lack thereof will determine how your finished job looks. (2)Degreasing is important, yet so is removing any and all degreasing agents and (3) stop wasting time on cold blues unless you are going to do a "classic rust blue" and this is very time consuming to accomplish.
Brownells' products are very good, however I personally do not like Oxyaffnate 7.
as it is too temperamental, yet gives a quality blue. The Oxpho Blue
⇦this on
Brownells or
eBay or
Amazon [affil links]
is good and is great for touch up work.
You have invested a lot of time and money according to your info on an inferior product when it is more economical to set up to do a hot nitrate blue that will produce a superior and durable finish.
I've been at this for 30 years and have just a bit of experience.
Bruce Thompson- Jefferson, Oregon
A. My Dad's 1939 Chemical Rubber Handbook has a formula that I've used successfully on Steel parts. I think it contained Ammonium Poly Sulfide and is pretty foolproof for a transparent blue color. Sulfur displaces Oxygen so it prevents Rust and doesn't etch the surface. Basically a monolayer of Iron Pyrite (FeS2), so won't protect against acid.
Stephen Jacks- Mount Vernon, Washington, USA
July 24, 2011
Q. I had a custom gun built ($5000.00). After break-in and scope, I took it on a hunt in snow; it rusted after 7 days of hunting. The gunsmith wants me to pay to have it re-blued. It looks way better now, heavier blue. Is that a warranty issue? I had the gun for 10 days. He is charging me for labor and bluing. I feel that it was a "light" blue in the first place because it looks so much thicker now.
gordon pulsifer- pueblo colorado usa
April 28, 2012
A. Hi Gordon.
After spending that much for a custom gun, I can certainly understand how you would expect it to last more than 10 days, or at least to get a free re-work if it failed that soon. So I am not advising you against leaning on the gunsmith for a little compromise in view of your large expenditure with him, but I am telling you that bluing/black oxide has no corrosion resistance at all and it is only the wax or oil that you keep on it that resists rust. It must be lovingly waxed, oiled, or at least wiped with WD-40 ⇦this on eBay or Amazon [affil links] , very frequently, since it will rust as soon as the oil is gone. Good luck.
Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
April 30, 2012
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