Black Phosphate Treatment?

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dusterdemon

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I’ve got some front suspension hardware that I would like to treat with black phosphate. Has anyone done this at home? Where did you get the solution? Thanks Warren
 
I’ve got some front suspension hardware that I would like to treat with black phosphate. Has anyone done this at home? Where did you get the solution? Thanks Warren
Are you sure that you want to put black phosphate coating on suspension parts.
Black phosphate is a coating used on automotive bolts. It’s primarily purpose there is to act as a ‘sponge’ on the surface of the threads and bolt body to hold oil. The oil is there to act as a rust inhibitor while the bolts are in boxed storage prior to use and as a lubricant when the bolts are installed.
The oil retention - rust preservation of black phosphate and oil is ok for new bolts stored inside in boxes, it would not hold up well under a car in actual use.
Probably the best no rust coating would be to have the parts powder coated.
If you don’t want to pay for that,
1) John Deere Blitz Black is a spray paint color available at John Deere Tractor stores that gives a nice soft flat black that looks very much like OE. Probably as good as any other spray bomb paint for rust protection.
2) Tractor Supply Inplement Black + Hardner additive is a do it yourself paint that can be thinned and sprayed. A little flatter than the JD paint mentioned above, but is a really tough paint that would give superior rust and abrasion resistance. Once the hardner is put in this paint will cure in a sealed container.
It is really tough.
 
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Stuff that was originally black phosphate will be all rust now. K member bolts are a good example. You can wax them and it will hold up well. Just throw some more wax on them when you do an oil change.
I have a commercial guy I send my stuff too but caswell sells DIY kits and they work well.
https://caswellplating.com/black-oxide-kits.html
 
Stuff that was originally black phosphate will be all rust now. K member bolts are a good example. You can wax them and it will hold up well. Just throw some more wax on them when you do an oil change.
I have a commercial guy I send my stuff too but caswell sells DIY kits and they work well.
https://caswellplating.com/black-oxide-kits.html
Is your commercial guy pretty reasonable? Thanks Warren
 
Hard to judge. I usually send him big boxes of bolts at a time. I also degrease and glass bead them which saves money.
I can dig up his info if you want it. He also does clear zinc and yellow zinc.
 
Actually I posted his info on here back in 2018
PLATING Cad -clear or yellow. Zinc in clear,yellow and black. Black zinc phosphate.
Eric Manuel
1058 N. Pasadena Ave.
Elyria, Ohio 44035
3404@oh.rr.com
 
Phosphate is an easy DIY, just read some articles and ensure you run a few fistful of nails or steel wool in the bath before parts.

Also, since it's an acid process, you need to do a hydrogen embrittlement relief by baking the parts at about 350F for an hour or two. Otherwise you can sometimes get brittle fractures. Uncommon, but it's so cheap and easy to do the relief that you might as well.

Lps3 is a great long term rust inhibitor and can work well on underbody hardware.
 
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