Black Phosphate Experiment

[Gerard F.]

And it works on zinc plated bolts too:


Here's what they looked like before:

ttp://i40.photobucket.com/albums/e244/gjfeng/ZPbolts3-before.jpg

Thes are store bought plated bolts. The third one from the left was pickled in Jasco Metal Etch (2 to 1 spray on). The others were just degreased with hot Simple Green (1), Hot TSP (2) and diluted Metal Etch (4). The 3rd one came out the best.

Here's the setup:


Same setup as the Gray Phosphate I used for the 67 Alternator pulley. Zinc phosphate solution, cook for 20 minutes in a crockpot, or until the desired darkness of gray. This time I added OEM Black (Quick Black) on the left (at 1/2 oz per quart) to the 1 oz per quart zinc phosphate. But you have to hit them with WD-40 or Tri-Flo as soon as they are initially dried.

And I even tried it on original bolts. These are 67 seat track bolts:


Trick is to get them down to bare metal. Unfortunately I could not get the pits out of these ones. What do you think?

I certify that I did not use my wife's crockpot on this project. After the first episode, I now have a collection of crockpots from the dump (recycling store) and have never paid more then $5 for the fanciest one.

Jerry Fuccillo
#42179

[Gerard F.]

Re: Here's the before

picture #2

[Rob M.]

Re: Here's the before

Cool pictures and experiment. Keep us posted. I have a blackning kit in my cupboard in my workshop but didn't had the guts to give it a shot...

greetings,
Rob.

[Charles P.]

Re: Black Phosphate Experiment

Jerry,
For flat washers, lock washers and hex nuts I will most likely be starting with zinc plated off the rack also. I think the bolt that you used the Jasco metal etch came out the best also. Where did you obtain the jasco from and how did you use it (hot, cold, diluted and how)? The pickling seemed to open up the pores of the metal and allow for a more uniform coverage of the zinc phosphate. I can't tell from my computer but do these show any crystalline sparkle like black phosphate??

[Gerard F.]

Re: Black Phosphate Experiment

Charles,

You can get Jasco Metal Etch at most hardware stores. It's a metal paint prep.
I cut it 2 water to 1 metal etch, and put it in a spray bottle, garage cold. I spray the parts in a poly freezer container, when the bottom fills up, I then just let them sit in the solution for about 2O minutes until the bright bolts are dull looking. Metal Etch is mainly Phosphoric Acid and seems to work well with the zinc phosphate, in fact if you leave the zinc bolts in the etch solution too long they will start turning black.

Be sure to where gloves, and eye protection, and don't breath in the vapors, very irritating. Have plenty of ventilation in the area you are working, and also where you are cooking the phosphate.

Here's a some other zinc plated bolts I did the same way, and a bare spade bit:


The spade bit was very rusty so I soaked it in muriatic for a few hours and then polished it to bare metal with a nylok brush.

The finish on the bolts and the bit are about the same. It is like a satin finish. If you take them out in sunlight you'll see the fine speckles and the color is more a dark charcoal gray rather than true black.

Guess what the mesh in the pic is. It's poly roof gutter screen, great for holding the bolts when you are dipping them in the hot phosphate mix.

Having fun,

Jerry Fuccillo
#42179

[dick foehringer]

Re: Black Phosphate Experiment

i use a product from palmetto enterprises. called zinc parkerizing solution. you first media blast the bolts, hinges, whatever then you dilute the solution at 4oz to gallon of water i think. directions are on the bottle. then you bring the mixture up to near boiling (i use my gas grill) and drop in the parts. the longer you cook them the darker they get. to stop the process you spray the parts down with WD40. you can get it in quarts or gallons. works great.fyi, dick