Nitre Bluing

[no4mk1t]

Really enjoyed these two Rust/niter threads. Thank you for posting. What type of pot are you using to melt the salts in? I presume it re-solidified as it cooled. Does the solution become weaker as it is reused?

Thanks!
I would encourage those who want to try these 19th Century bluing techniques to do so. Both processes are low tech and simple to do. All the work is in the metal prep.
The pot used in the Nitre thread is a simple cast iron pot. You can use anything that will withstand the 850* temp. I first tried a bread pan. My only mistake was the one I bought was painted black. I assumed the paint was high temp and would be OK. Wrong. If you are going to use a bread pan, get one that is bare steel.

The salts are granulated when you buy them. After you melt them and they cool down, they solidify, but are easily melted again for subsequent uses. There is no solution to weaken as with parkerizing or hot caustic bluing methods. The salts are simply a medium to heat the parts to the required temperature. The heat itself does the bluing. Small parts like pins and screws can be blued in the flame of a propane torch.

[bigduke6]

An interesting thread no4 mk1 t, looking forward to the finished article.

The black stuff inside an alkaline battery is manganese dioxide. Just crush it into powder before you used it.

After crushing several batteries to get the Manganese dioxide out, for parkerizing I decided to buy a container of the stuff from ebay, never give it much thought regarding the stuff itself, but there is a few warnings on the tub, don't inhale and avoid contact with eyes........ breaking up one battery in particular I was covered in the stuff. Whilst ordering the dioxide got myself some Phosphoric acid also.

[Vincent]

What is your DIY Parkerizing solution recipe?

[no4mk1t]

What is your DIY Parkerizing solution recipe?

What parkerizing I've done, I've bought the solution, but here's a recipe I found and intend to try if the chemicals can be found.

Dick Culver is a former Mustang Major in the USMC.




Kitchen Stove Parkerizing

By Dick Culver

NOTE: I originally gave this formula to an interested individual when we were posting on the Ohio site, but it was lost in the transfer. I publish it again here with the disclaimer that I don’t wanna’ be responsible for anyone ruining a $1000 part or becoming a vegetable from inhaling the fumes from some noxious brew. I’ve done it on numerous occasions with no ill effect (some will differ in their opinion of my mental state of course) but if you choose to play around with chemical formulas, you are strictly on your own!

ROC

INSTRUCTIONS FOR "HOME-BREW" PARKERIZING:

You need a number of things to do a "home-brew" "Parker-job", but only 4 ingredients.

1. Phosphoric Acid (the active ingredient in Naval Jelly) usually procured at a chemical supply house.

2. Powdered Manganese Dioxide (a very dense and heavy dark gray to black powder) also available at any chemical supply house.

3. Distilled water (I’ve used tap water, but the distilled stuff gives more consistent results.

4. A biscuit of steel wool (don’t use soap pads or Brillo pads!)

I used to do this on the kitchen stove (I wasn’t married in those days) in a one gallon Pyrex beaker (these little beasts are expensive, so be careful with them). Metal pots don’t work as well (if at all) I understand, but then I never used anything else but Pyrex.



Proceed as follows:

1. Use one whiskey jigger (yeah, this is really scientific, right?) of phosphoric acid added to the water. Remember your high school chemistry, ALWAYS add the acid to the water, and it is best done by pouring it down a glass rod!

2. Use one whiskey jigger of the (powdered) Manganese Dioxide in the solution.

3. Bring the solution to an extremely slooowwww rolling boil .

4. Now add your biscuit of steel wool.

I used wooden sticks placed across the top of the beaker and suspended the parts in the solution using steel or iron "machinist’s wire or some such. DON’T use painted coat hangers or any wire with grease on it! You can usually get this stuff from a machine shop or from Brownell’s.

The parts should be totally immersed in the solution, being careful that anywhere the wire touches the part won’t show on the finished part (usually easy to do – like in the firing pin hole of a bolt). The part(s) to be Parkerized should be totally "de-greased" and sand or bead blasted prior to finishing (depending on the texture you desire on the finished part). Once you have bead blasted the part, you should handle the part with gloves (never greasy hands) and store them wrapped in clean paper towels awaiting the Parker Bath. Any grease on the parts or wire will cause what can only be politely called a variation in color (the parts come out streaked and spotted like a "paint horse").

I usually let the part remain in the solution for a total of 20 minutes (less MAY work, but I was told 20 minutes so that’s what I used and it worked marvelously). When you withdraw the part, immediately rinse it in hot running water to get the solution off of it. Use extremely hot water, and the part will dry itself. Let it dry (and get cool enough to touch) on some clean paper towels, spray on some lubricant and viola’ you are done!

Rumor control said that if you immersed the freshly rinsed and still hot part in cosmoline, it would give the sometimes sought after "gray-green" tint to it. I have never tried it. Cosmoline is still available from Brownells if you are adventurous!

The original formula called for iron filings vice steel wool, but since I didn’t have any floating around, and didn’t want to file on the cast iron stove, I found that the steel wool worked just fine. What you get is a chemical reaction that causes an iron phosphate to form on the metal (steel phosphate I suppose, using steel wool). I have found that the resultant finish is just as durable as the Arsenal finishes and has exactly the same appearance! – an attractive dark gray, almost black. Some say that adding more manganese dioxide causes a darker finish, but I’ve never tried it, as I was happy with what I got!

We often used this technique when finishing .45s built on early Essex frames that needed a lot of fitting, thus often requiring the removal of offending metal. I used to checker the front straps (also violating the finish in a rather spectacular fashion) and the resultant finish worked great and showed little or no wear even with extensive use – much like the official GI finish. I’m still using a wadcutter gun I performed the magic on back in the ‘70s and it still looks new.

A couple of cautions:

1. Always be careful of any sort of acid, even such an innocuous acid as phosphoric. I certainly would never deliberately inhale the fumes (although there is no great odor to the process that I could tell, but then I smoke cigars). I started doing this back in the early to mid ‘70s and still have no "twitch" that I can directly attribute to Parkerizing on the kitchen stove. Just use common sense, WEAR GLOVES AND EYE PROTECTION ANYTIME YOU ARE PLAYING AROUND WITH BOILING SOLUTIONS (with or without acids being involved).

2. Be very careful not to cause any splashes with the boiling solution (of course the same can be said of boiling corn).

3. Prepare your area and your parts before hand, don’t try to do this on the spur of the moment.

4. Send your wife to see "Gone With the Wind" or "Titanic" or some other movie that whiles away a number of hours. If you ever want to do this again, make sure the kitchen is spiffy when she returns! In Gloria’s case, she would be attaching the parts, but then I’m just lucky in that respect...

5. Once you have allowed the solution to cool, you are DONE! Re-heating it don’t cut it, It simply doesn’t work (I’ve tried it on several occasions). Have everything that you want to Parkerize ready to go when you fire up the solution. You can keep Parkerizing as long as the solution is hot, but allowing it to get cold kills it – you’ve gotta’ brew up a new solution and start from scratch.

6. Do not name me in any divorce proceedings!

Good luck!

[Topfmine]

Just been reading up on your nitre blue, would this finish turn black if the metal was sand or bead blasted to give a Matt finish. Does the nitre solution spit and bubble like blueing hot salts or does it simmer gently away and how do you deal with evaporation of the solution.
Looking at the formulas for phosphating any one know the formular of the pre dip black parkerizing solution?

[no4mk1t]

Just been reading up on your nitre blue, would this finish turn black if the metal was sand or bead blasted to give a Matt finish. Does the nitre solution spit and bubble like blueing hot salts or does it simmer gently away and how do you deal with evaporation of the solution.
Looking at the formulas for phosphating any one know the formular of the pre dip black parkerizing solution?

With a bead blast prep, the resultant finish would likely be a matte blue/black similar to the pics of the Krag parts earlier in this thread, just without the gloss.
The Nitre process involves molten salt as a medium to heat the parts to the temp where the heat turns them blue. There is no solution to evaporate

[Trap4570]

Potassium nitrate melts at about the same temperature as lead. The amount of time the part is submerged determines the finish. I have used it on parts to bring out a straw color. I usually buy a 5 or 10 pound bag from Duda Diesel. It's used in making bio diesel. They have other useful chemicals as well for cleaning and what-not. I make sure that I get the 99 percent pure as they offer different grades.