Ok. I’ll give it a try. Up in a tree stand at the moment. .
I blued a lot of guns in my smithing career, but when I retired I sold all that stuff. A couple years ago, I built a competition muzzle loading pistol and wanted to blue it. Didn't want to buy 50 pounds of bluing salts and a whole set up, and having worked as a chemist for awhile, I started looking to make some hot blue salts. A net search showed someone already had, and I modified their process a bit, but it worked as well as the expensive salts from Brownells. Getting a gun blued these days is expensive, long waits, shipping costs etc. and the people often use soft buffing wheels that round off edges, dish flats, distort lettering etc etc. and glass beads that are too coarse for my taste. A careful hobby gunsmith can prep their own pistol as well as, and probably better than some commercial outfits I've seen, with patience. The ingredients are found at hardware stores or garden centers and pretty cheap.
I just never liked the coatings some are using. A deep hot blued classic finish is a beautiful thing to me. Some of the colored coatings are nice for durability, but still look painted...
Anyway, here's the formula I use. The solution can be stored and reused, by adding salts as needed to raise temp or water to lower it. Be careful, use face shield and gloves. This stuff will eat your hide or anything organic it encounters. I use stainless steam table pans I got on ebay and a coleman 2 burner camp stove for longer parts. Be sure to suspend your parts on black non plated iron wire. You can make any size batch, just use the ratio as initially and keep an eye on the temps. I use 270-295 deg F.
The homemade salts are great for nearly anyone doing small jobs -- it is very quick and economical to heat only 1 gallon of salts, blue the parts, and shutdown in less than an hour start to finish.
Degreasing is crucial. I use tri-sodium phosphate and detergents. But some say the sodium hydroxide (lye) will degrease anyway. I never trusted that.
The depth of the blackening color increases with more time in the bath and a repeat session can be done if there are touch-ups or to add more/depth of color. I found the exact same results from the process and it matches perfectly even after sanding, filing, bead blasting, etc. I scratched a part and just filed off the scratch, did a quick bead blast, and returned to the salts and reblued the exposed steel until it matched the rest of the part. The low temperature (255 to 275 degrees is helpful as I need only about 15 to 20 minutes to bring room temperature solution up to a full boil, then perhaps 20 minutes to 30 minutes exposure of the parts in the salts for a nice black result. If I cover the heated salts and turn off the heat it stays hot for quite a while so I can bring it back up to boil in 5 to 10 minutes for rework or additional sessions post inspection/cleanup on the first run.
I prefer to watch the pot while it is going, so I never leave it unattended while doing cleanup.
(5) 16 oz or 18 oz containers of Sodium Hydroxide (lye), Recommended Brand: Lewis Red Devil Lye Drain Opener (100% Lye). It must say 100% lye. Drain openers that explicitly say 100% lye are acceptable, howeer any drain opener that does not say 100% lye will not work! Lewis Red Devil Lye is a very common item so it should be available at a local home center, hardware or grocery store. The package is an 18oz container that costs about $3.19.
(Edited to add it has been brought to my attention that Red Devil Drain opener is no longer manufufactured, below is what someone kindly emailed me.
After a bit more research I did find that tech-grade sodium hydroxide is still available for sale at a variety of places with the most common being those that supply the homemade soap and candle making hobbies. I went ahead and ordered 10 lbs and with shipping it still only came out to $3.00 a pound which is comparable to the Red Devil lye if it had still been available. I purchased it here:
(1) 4 Pound Box/Bag of Sodium Nitrate (Nitrate of Soda), Recommended Brand(s): Bonide Nitrate of Soda Fertilizer, Dragon Nitrate of Soda Fertilizer, Hoffman Nitrate of Soda Fertilizer. This item is Sodium Nitrate and comes in 4lb bags or boxes. Garden centers and hardware stores carry this or can get it. It is listed as containing 16-0-0 or 15-0-0 Nitrate Nitrogen. If you prefer, you can order online by using a search engine such as google.com, froogle.com, shopping.yahoo.com, or bizrate.com
to search for "Nitrate of Soda" and you will find merchants that sell it from $6.49 for 4lbs to $14.95 for 8lbs.
(2) 1 Gallon Containers of Distilled Water. Some people have no trouble with tap water, but I think it must be distilled so it does not contain minerals and it is available at every grocery store. I prefer to keep track of the water I add to the salts.
See part 2.
I can’t find this in the Articles, apparently only you can read it. Why can’t you just post your info in this thread for everyone to read easily rather than sending out emails, etc? If you need more room, just make multiple posts in this thread.
It is your thread, so please clog it up with information.
p in tree