Sciencemadness Discussion Board

Phosphating and bluing chemistry ?

RonPaul2012 - 1-7-2012 at 07:50

I am interested in the chemistry of phosphating (parkerizing) and bluing.

I have researched a lot lately and I cannot find a concise scientific explaination for what goes on in either of these processes , only a bunch of vague explainations that don't seem to compliment each other at all.

I realize that this is a broad subject and I don't expext to have all of my questions answered at the same time , so take your time.

Any help would be appreciated.

Thank you :)

Maya - 1-7-2012 at 08:34

maybe some of the gun forums would have more practical applications and procedures.

basically as I understand it you are just etching the metal parts with a phosphoric acid solution to form a thin layer of the inert metal phosphate

RonPaul2012 - 1-7-2012 at 08:44

Quote: Originally posted by Maya  
maybe some of the gun forums would have more practical applications and procedures.

basically as I understand it you are just etching the metal parts with a phosphoric acid solution to form a thin layer of the inert metal phosphate
I generally understand the procedure but a gun forum will be of no use to me since I have no practical application for these processes , I am just interested in the chemistry of it.

inspector071 - 1-7-2012 at 10:07

Being an avid firearms enthusiast as well as a chemistry major has always made me very interested in the chemistry of firearms, whether it be the different types of conversion coatings used to protect the steel or the energetics that go into the primers and smokeless powder. I, too, wish to learn more about the different finishes of firearms and how they are applied. Recently I've been doing some reading about the various methods of bluing steel. The traditional hot bluing method involves placing the steel parts into a near boiling solution of a nitrate (such as potassium or sodium) and sodium hydroxide. The oxidizing solution preferentially forms iron(II, III) oxide. This layer is not as smooth as polished steel, and can soak a coat of oil to add some water resistance.

In the next week I'm going to try my hand at hot bluing various steel pieces and see how they turn out. I'll post some results here if you'd like to see them.