Topic: Phosphating 101 -

[rtate]

Thanks Jim, I appreciate the help and your patience   

[jwc66k]

I went back to the initial post to see if I missed something. (I did clean up some of the "alternate special characters".) Literally every question you asked, or every situation you posed, was addressed by me or by other members of this forum that had "alternatives" to materials or processes.
I now ask you - please read the entire thread again - please.
Jim

[rtate]

The zinc phosphate solution that I am going to use says to put some "coarse steel wool" in the solution before phosphating and parts.
Has anyone done this ?
Waht is the purpose of the steel wool ?

[Bossbill]

If you put the part in some muriatic acid it will bubble wildly as long as the zinc or cad are on it . After the the zinc or cad is dissolved by the acid (typically less then 5 minutes) the bubbles will slow dramatically which means the zinc or cad is gone. I use this process when ever I have a plating issue like that and it soles the problem the quickest.

Rereading this thread.

I have two plastic coffee containers. One contains muriatic acid and the other baking soda in water.
I either place the acid outside and use an acid mask or in my vent hood (and still use a mask). The fumes coming off are nasty.
I have a roll of 18 gauge copper wire and snip off 6 inches or so to suspend the part in the acid. After all the bubbles from the part in the acid are gone I dip the part into the baking soda mix until those neutralizing  bubbles disappear.

If I'm plating I suspend the part in 5% my rustic acid if I can't get to it immediately since the part can surface rust quickly.

 I keep the shop under 60% humidity running a large dehumidifier. I live amongst trees and streams  which tends to raise humidity levels compared to the subdivisions.

[jwc66k]

The zinc phosphate solution that I am going to use says to put some "coarse steel wool" in the solution before phosphating and parts.
Has anyone done this ?
Waht is the purpose of the steel wool ?

Beats me. I've used Parkerizing liquids on "barrels" and on hardware but never read anything about "steel wool" in the solution.
I guess don't bother.
Jim

[CharlesTurner]

Found this info on the steel wool posted by a chemist:





In my day , and maybe still, in Industry , it was called "Aging" the Bath-,??-of Chemicals.


It's purpose is to introduce Iron, which with use, would happen anyway.   With low Iron levels, thin , patchy coatings would be evident. As the Iron content increased with use, the coatings would become denser and exhibit the sought after appearance.   Doing it this way would produce a lot of scrap parts, but would increase the Iron levels (Titratable !) using KmNo4??Potassium Permanganate.   Iron in solution is also an Oxidising agent, as is Sodium Nitrite (an accelerator) and as such the Titration method is the same.


Typically, again, in well formulated Compounds, there is no need to add steel wool, nuts and bolts etc to add Iron.


Immersion Class 1 phosphates can Run "on the Iron side"??Higher temp.  or "on the Nitrite side", ZINC only.   Nitrite keeps the Iron out of solution, allows faster coatiing times and smoother denser crystal formation, preferred for pre Paint applications.


To much iron will cause thin coarse coatings and eventually no coating if really high.


What you're doing in adding some old to new is Borderline brilliant !!? obviously the old will have Fe which can only help with a new mix.

[bullitt68]

The zinc phosphate solution that I am going to use says to put some "coarse steel wool" in the solution before phosphating and parts.
Has anyone done this ?
Waht is the purpose of the steel wool ?

I am not familiar with that product, but I use hot phosphate (parkerizing solution) all the time. Is your product a cold or hot phosphating process? I use steel wool to apply cold phosphate gel and it works great .I apply the gel to the steel wool and then burnish the part. It works great for certain applications. However the end result is dramatically different between the two processes. For a light coating that looks like natural metal I recommend cold gel phosphate. For fasteners and other parts that need a dark consistent finish I suggest the Manganese hot phosphate solution. FYI you can also get zinc hot phosphate solution as well.

[J_Speegle]

I've seen where people have been using or suggesting the steel wool usage for decades though never choose to go that direction. As Bill suggests there are so many different products and processes to recreate all sorts of tones and tints when using multiple products and methods. All a conclusion of experimenting

SO glad we don't have to deal with the humidity out here normally. Just something else for some of us to contend with and another thing to worry about

[rtate]

@bullitt68 , It is a hot solution that I will be using.
I think I will go without the steel wool...

[Bossbill]

I would suggest you go to the member restoration area and look at what members have used to see if the color and tone are what you are after. We talk about our favorites but both bullitt68 and I tend toward the Palmetto phosphorizing solution and the Brownells Oxpho-Blue.
But whatever the product or user, compare other's work  and make your own call.

But, don't expect things to work the first time. I've been experimenting for years and still have to redo things.

Oh, on edit I should add -- get a stainless thermometer. You need to watch your temps. Bring the water up to at least 180 def F and add the compound to the water. General rule is add acid to water so do that with the parkerizing solution as well.
Unlike some I use a single "5th" burner -- a single electric. It is real easy to keep the temp and I'm not a fan of open flame in that area of my workshop.

[rtate]

Thanks Bossbill,great tips !
I also plan to preheat the parts in the oven as well, so that the temp drop will be very small...

[rockhouse66]

I replate distributor hold down clips and have had issues with them not turning out well and/or starting to rust later.  I now do this for these particular parts;
blast clean
muriatic acid dip
water rinse
zinc phosphate using Palmetto product around 190-200 degrees
dip in WD 40 to neutralize
blow them relatively dry and then bake in a toaster oven at 225 or so to completely dry (they look bad/crusty when I take them out of the oven)
soak in 30W motor oil for 24 hrs or more
leave on paper towels for a day or two until relatively free of oil droplets and store in this condition
wipe dry when installing


Not sure why these are fighting me - must be a metallurgy thing - but this works now so this is what I do.  And people ask me how long it takes to restore something; how do you account for the time spent prepping component parts?

[CharlesTurner]

Jim:  Is your media clean that is used to blast the pieces?  The muriatic acid ought to prevent any issues.  I normally just blow dry after rinsing off in water and soak everything in motor oil for 24 hours.

[jwc66k]

This picture was taken on 7/18/22 around 8:05PM PDT. The distributor clip was phosphated at least 10 years ago.

muriatic acid dip
water rinse

Why? Muriatic acid is primarlily use to remove zinc or cad plating.

zinc phosphate using Palmetto product around 190-200 degrees

Yes. Product and temperature are good. Experiment to get the phosphoric acid-water bath percentages to give you the finish shade you want.

dip in WD 40 to neutralize

You have just mixed residual phosphoric acid and WD-40. Rinse in tap water to: stop the phosphoric process; cool the item to handle.

blow them relatively dry and then bake in a toaster oven at 225 or so to completely dry (they look bad/crusty when I take them out of the oven)

I "air dry". Of course the summer daytime humidity "here" is in the 30-40 percent range, but every attempt by me to blow air on parts results in excessive rust. And a "toaster oven"? Afternoon temperatures here do the trick. In an hour after the water rinse/cooling step, I spray WD-40.

soak in 30W motor oil for 24 hrs or more

Never have. (OK, once.) The WD-40 does it for me. (I also use WD-40 to flush out tight spaces and joints, like hood hinges - second pic.)

leave on paper towels for a day or two until relatively free of oil droplets and store in this condition
wipe dry when installing

I leave the WD-40 on. I don't know if it gets absorbed into the metal, or evaporates. For storage, leave it.

Not sure why these are fighting me - must be a metallurgy thing - but this works now so this is what I do.  And people ask me how long it takes to restore something; how do you account for the time spent prepping component parts?

When re-inventing the wheel  make sure it does what you want, and don't speed excessive time on it.
Jim
PS: Go back and re-read the procedure from the start.

[Bob Gaines]

I get flash rust issues when blow drying also. I typically pat dry with a rag ,towel etc. before letting air dry or baking.