Parkerizing formula, process and Q&A's

A. Hi cousin Dighe. The problem with such questions is that people must reply "what do you want to test about the parkerizing, and what values from those tests should indicate passing vs. failing?"  :-)

But the resolution to the problem is actually simple: you need to parkerize/phosphatize in accordance with some particular specification. Then the specification will tell you what you need to test, and how, and what constitutes compliance. So look through some star washer and/or phosphatizing specifications and pick one. You could look at MIL-DTL-16232 [from DLA] as a starting point because access is free.

Luck & Regards,

A. Hi Vadim. We added your question to a thread which already has a lot of information about formulation of Mn Phosphatizing processes. Thread 31345 also addresses this topic. Thread 14221 offers good info on activation chemistry.

You are certainly welcome to precede down this path if you wish. But just in case you didn't know, virtually no one formulates their own phosphatizing and activation solutions these days; rather, they buy proprietary processes from suppliers to the industry.

But what is your current formulation and what problems is it causing that you feel an improve formulation will resolve?

Luck & Regards,

A. "Parkerizing" is the trade name for a phosphating process by Parker. They are now Parker+Amchem whose parent company is Germany based Henkel.

I'm not sure that it is a phosphating process. It could be a Gun "bluing" process.This is a controlled oxide formation process. There are various companies offering these products. They should be able to provide you with the information you are looking for, and would process some samples for you as well.

Good luck

A. For my opinion your process is heavy coating Zinc Phosphating and then you have to oil the gun.

The Process Sequence is :

1. Alkaline Cleaning
2. Rinse
3. Oxide removal with Inhibited HCL
4. Rinse
5. Grain Refining
6. Heavy Zinc Phosphate
7. Rinse
8. Chromate Sealing
9. Rinse
10. Oiling

For my opinion you have to release hydrogen by entering the gun into oven at 200° C for 3 hr before oiling.

A. Parkerizing or Phosphating is a very well known process in the firearm industry. Parkerizing has been used by the U.S. military since the early 1900's. The Patents for Parkerizing are or were (my references are rather outdated) held by the Parker Rust Proof Company, Detroit, Michigan.

The basic formula consists of;

Phosphoric Acid

iron filings [affil links]or Manganese Dioxide

Distilled Water

Parts may be sand or bead blasted before finishing but good results may also be produced on highly polished parts. The Parkerizing process should only be used on on exterior surfaces to protect close tolerance parts. Parts are neutralized immediately after removal from Parkerizing solution by boiling in plain water.

! Hello all! Just a note to anyone interested in the history of The Parker Process. Clark W. Parker was my great-great grandfather, the one who invented the Parker Process. I was surfing through the net and found this site. Sincerely,

---

Hi Sharon. Happy to meet you. We wish you as much success in your endeavors as your great-great-grandfather :-)

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

A. Look at Metal Finishing, (1979, May) Vol 77, No. 5, page 99. Phosphating of Steel Using trisodium phosphate ⇦ this on eBay or Amazon [affil links] , or see Rajagopalan et al., Central Electrochemical Research Institute, Karaikudi, India. Good Luck!

A. As previously mentioned, Parkerize is a Trade name which may consist of either Iron (Gray) Zinc (Green) or Manganese (Black) phosphate finishes. They have evolved through the year. There are other companies which make similar type products and some better than the Parker Brands.

To be applied properly, they need to be sent to a professional who has the equipment to maintain the temperatures, and the bath consistencies. To achieve maximum corrosion protection, other processes need to be applied to the phosphate finishes and the metals baked. Forget about Parkerize, it is an old obsolete method of corrosion protection, no mater what method is used.

A lot of gun smiths Parkerize guns but are not using the industrial methods of application and will not hold up. After the phosphate coatings, you need to apply another dry film lubricant and corrosion barrier coating. The results is a flat black durable finish which is more corrosion resistant than Stainless Steel. Phosphate finishing is only the first step of a good gun finish.

Parkerizing Solution at Brownells


(affil links)

I would like to contact Geoff Schecht with regard to his offer. We shoot and restore old Military Firearms. Any help you can give me with formulas and processes would be greatly appreciated. Regards

I recently purchased an old military surplus handgun that needs to be refinished. I wish to Parkerize the gun and have gathered a lot of useful info on this site. However, If Mr. Geoff Schecht would contact me to share his info it would be VERY helpful for a beginner to Parkerizing.

WD-40 in bulk

on eBay or

Amazon

(affil links)

A I build guns for a living . I also Parkerize on a daily basis. I use a mixture of 1 gallon technical grade Phosphoric acid to 8 ounces manganese dioxide . The Phosphoric acid is mixed with 9 gallons water in a stainless trough and brought to a rolling boil.

The Manganese Dioxide is then slowly mixed in the solution and boiled for 10 minutes. When the parts are ready to Parkerize after blasting with coarse ground glass I reheat the solution to 190 °F and immerse the part in the solution until foaming stops.

Then I remove the part from the solution, rinse with cold water, oil with a mixture of 1 gallon WD-40 ⇦ this on eBay or Amazon [affil links] and 1 quart chainsaw oil, dry and re-oil. I have built over 300 guns this year alone using this method. The finished guns are near black and retain oil very well.

A. After reading all the comments above, I took to the kitchen.

My wife has not left me yet over the experiment but I don't think I will get away with a big project. I attempted to coat a steal punch. I did not do too good a job of cleaning the punch so the finish is a bit splotchy.

I used 2 cups of tap water, one cup of white vinegar ⇦in bulk on eBay or Amazon [affil links] , and one heaping table spoon of epsom salt. The water and vinegar was brought to a boil. Then I added the epsom salt. After boiling this for a about 10 minutes, I added my somewhat clean tool steel punch. After simmering this stew for 20 minutes, I removed the punch and rinsed in lots of hot water. Dried the punch and applied lots of oil.

The darn thing looks fairly good. I think with a Parkerizing kit anyone should be able to follow the direction and do a good job. Good luck to all of us who dream of Parkerizing that old piece of junk .22 or .410.

A. Found this after my own search for Parkerizing finishes.

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!

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 ⇦ this on eBay or Amazon [affil links] ) 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 00 steel wool ⇦ this on eBay or Amazon [affil links] (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 "machinists 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 Brownells [ Brownells home page (affil link) ] .

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 ñ 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 voila 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 [ Brownells home page (affil link) ] if you are adventurous!

The original formula called for iron filings vs. 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! ñ 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 ñ 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! Reheating 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 ñ you've gotta brew up a new solution and start from scratch.

6. Do not name me in any divorce proceedings!

Good luck!