Parkerizing

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jscarmozza
Posts: 599
Joined: Mon Mar 03, 2014 5:09 pm

Parkerizing

Post by jscarmozza »

I'm looking for a surface treatment for exposed steel parts on my locomotive and was researching Parkerizing, do any of you have experience with the process, how difficult is it and how well did the treated parts turn out? :| Thanks, John
earlgo
Posts: 1794
Joined: Sat Jan 29, 2011 11:38 am
Location: NE Ohio

Re: Parkerizing

Post by earlgo »

First, let me say that I don't know anything about parkerizing.
In John Traister's book "Professional Care and Finishing of Gun Metal", chapter 10 explains the materials and methods for parkerizing. You might check with Brownell's in Montezuma, Iowa as they list parkerizing materials on their website. https://www.brownells.com/gunsmith-tool ... /index.htm
Good luck with large locomotive parts.
--earlgo
Before you do anything, you must do something else first. - Washington's principle.
John Hasler
Posts: 1852
Joined: Tue Dec 06, 2016 4:05 pm
Location: Elmwood, Wisconsin

Re: Parkerizing

Post by John Hasler »

I've had good luck making steel and cast iron machine parts rust resistant (though not rust proof) with phosphoric acid. I clean the parts with acetone and then soak them overnight in 10% phosphoric acid (I use dairy milkstone remover). Make sure the parts are fully submersed and exposed to the solution. I then rinse with hot water, wiping off loose deposits. Don't use a stiff brush. I then dry them with hot air or sunlight and apply a drying oil such as tung oil or boiled linseed oil. Gives an "iron grey" finish that varies a bit depending on the alloy. You may need to renew the oil from time to time.
jscarmozza
Posts: 599
Joined: Mon Mar 03, 2014 5:09 pm

Re: Parkerizing

Post by jscarmozza »

John, lots of questions beings you've done it. Do you use a heated tank with your process, it looks like the commercial products require moderate heating of the solution tank? What finish do you recommend on the bare steel parts? I was thinking about getting the parts sand blasted to get a satin finish and hide some of the tool marks, do you think that would work? From what I have read, the color may vary from part to part depending on the steel alloy, has that been your experience? Earlgo's link to Brownells products looks like a good way to get started, their solution supposedly comes with lots of instructions...I need that. John I'm looking forward to your answers and insights.
Thanks guys
John Hasler
Posts: 1852
Joined: Tue Dec 06, 2016 4:05 pm
Location: Elmwood, Wisconsin

Re: Parkerizing

Post by John Hasler »

I have used a heated tank. The process goes much faster with heat and I think that the resulting coating is thicker. I don't usually bother, though. I just leave the part in for 3 or 4 hours, sometimes overnight. I'm not usually concerned about appearance (I'm doing parts for my power hacksaw now) but I've noticed that the process itself helps hide tool marks. Sandblasting could only help. The color does vary depending on the alloy, the finish, and even on the heat treatment history. It can vary slightly even with parts of identical alloy with identical histories if you don't maintain close process control. Fortunately I'm not doing display items. Cast iron always comes looking really nice, though. The finish is surprisingly durable. I did my bandsaw table several years ago and it hasn't worn through yet.

Adding manganese and/or zinc reportedly improves the corrosion resistance. I've experimented with that but haven't devleoped a process for regular use. There is also an electrochemical variation that looks interesting.

The other good reason to phosphate parts is as preparation for painting or gluing. The iron phosphate complex forming the finish is slightly porous and helps a lot with paint adhesion. You don't oil it when you intend to paint, of course.

The Brownell products use a different process. I've never used their stuff: I'm too stingy to buy it.
jscarmozza
Posts: 599
Joined: Mon Mar 03, 2014 5:09 pm

Re: Parkerizing

Post by jscarmozza »

Thank you John
jscarmozza
Posts: 599
Joined: Mon Mar 03, 2014 5:09 pm

Re: Parkerizing

Post by jscarmozza »

John Hasler, can I Parkerize an assembly or do I have to break it down to its individual parts?
Thanks, John
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