View Full Version : Parkerizing - can anyone talk about the chemical process?

February 06, 2009, 23:14
I need to know what is the gaseous product of the zinc phosphating process typically referred to as Parkerizing.

Also, if anyone knows what the chemical makeup of Shooter's Choice zinc phosphate solution is that would be helpful.

I'm trying to convince the wife that, unlike a bake-on finish that gives off VOCs phosphate finishing isn't dangerous.

Thanks in advance...

February 06, 2009, 23:47
The gas given off is hydrogen. At the amounts generated, it won't be a problem.

I don't know what's in the shooter's choice phospate solution. They don't list an MSDS for it on their website.

Some trace metals, like copper, nickel, and cadmium are sometimes added to zinc or manganese parkerizing solutions to help in activation or color. Nothing toxic. The most dangerous part is the phosphoric acid and once you've made up your solution from the concentrate, it's less concentrated than the phosphoric acid in a soft drink.

I wouldn't go around drinking the stuff, but you can tell your wife there's nothing to be deeply concerned about.

February 07, 2009, 10:47
Phosphoric acid is used in the FOOD INDUSTRY as a safe/no toxic way to STERLIZE containers and equipment...

February 09, 2009, 00:16
Gents, thanks for confirming what I suspected. I'll have to continue to show the wife that this isn't a process that's going to require a HAZMAT cleanup and contaminate the garage and its contents.

Hmm, I'm really hoping I can start using the tanks I picked up.

February 09, 2009, 09:53
It is an acid and the fumes can etch metal in high concentrations for long periods. If you don't do a good cleanup, you will get scale buildup - imagine high mineral concentration water for years. If you spill on sensitive skin, the acid is strong enough to burn either in concentrate or in diluted. In diluted, it is mild enough to put your hands in. On the other hand, ammonia cleaning solution will burn you, as will drain cleaner, so I don't put it any worse than household cleaners. Safe as long as you don't get cocky with it.

V guy
February 09, 2009, 10:03
Parkerizing is an acid process....bluing is an acid process....once in a while I need one or two small parts parkerized and discovered a crude but effective way to do them.....I get some phosphoric acid product like spray on"rust away" or somthing similar..I pour it all into the cut off bottom of a plastic gallon jug....put in some rusty soft metal bolts and pieces of rusty sheet metal..the rustier the better....make sure you little parts are clean and pop them in....the electrolytic action converts and tranfers the iron oxide --"rust" to the clean part in the form of a dark grey/black iron oxide based coating......crude parkerizing. takes between an hour and a few more depending onthe hardness of the part... Make sure you wash the part really well in hot water for to neutralize the acid and oil it for it will be dry and really soak up the oil....small Garand parts are what I end up doing and have even managed to get some color on the hard gas cyl locks and gas cylinders and plugs.....does smell..eventually the left over crud in the plastic jug gets kind of rancid after a few weeks of is toxic and will kill millions if not properly disposed of.....

February 09, 2009, 22:50
I think I'm just going to go ahead and try to find some small commercial space in the local area. It would make things a bit easier at home.

February 09, 2009, 23:44
Or just do it outside. Get a small propane stove, set the tank up on bricks with the burner underneath, heat up the solution, park, rinse and done.

Or, do it in the house when the wife isn't home. That's what I do. I can park quite a lot of parts when I'm on a deadline. Sort of like "The Bonnie Situation" in Pulp Fiction. Without a dead body, of course.

February 10, 2009, 05:44
The back deck makes an excellent parking area. (weather permitting)

February 10, 2009, 10:27
Originally posted by V guy
Parkerizing is an acid process....bluing is an acid process....

Minor detail, but bluing is not an acid process, it is a super-saturated basic sollution and much further from 0 on the pH than park. Also, with a 120 degree higher operating temp, and the propensity for caustic salts to spit when contacted with water makes is more hazardous by far.

Then there is peacock bluing which is really dangerous.

Ron Walker
February 10, 2009, 13:32
It's amazing what you can do with household items such as V guy suggests. I once experimented with a knife blade I wanted a non shiny rust resistant finish on. I used a pint of regular distilled vinegar in a jar, and added 1 tablespoon of salt. I then set up a 12v battery with a cathode and attached the blade to the negative as an anode, and suspended it in the solution overnight. What I got was a dull gray finish very resistant to wear and has never rusted in the 30 years since I built the knife. Ron

V guy
February 10, 2009, 14:13
I more or less was referring to the cold blue solutions that you can get from brownells like oxpho blue... will eat metal up is you are not careful, as I believe that those solutions are full of iron oxide in a phosphoric acid type solution...I was doing an old gun and the stuff ate up some of the markings and made them much more faint as they metal got eaten up...

The hot salts blueing is an entirely different animal for sure as is the rust blueing and the old dulite process ..Bill Adairs website discusses some of the old types of coloring like the dulite and oil types....for sure many ways to color metal. I heard that Adair just died last weekend by the way....

February 11, 2009, 18:34
so you guys are saying that if I used a kitchen pot for post park boiling and grain refiner all they need is just a clean up and they are good to use in the kitchen again? I seem to have this white dust like film in the pots even after cleaning 3X's

February 11, 2009, 20:15
I do not use anything from the wife's kitchen. I found a used electric range for $ 40 and put it into the garage. Put an outlet in the wall by the electric box.
You can fine used stainless pots at the yard sales or flea market.

Hope this helps.