Corerct finish for a 70 wiper arms and blades

[Steve D.]

The guide says that they should be a flat black finish. I have read several places where this flat finish was originally produced by a black phosphate. Not the type that has green and red specs but the formulation that is used to treat various bolts especially on the firewall. Can anybody shed some light on this?
Mine are clearly painted flat black. But I suspect that was the previous owners restoration method.
If they are phosphate blackened, does anybody know who would refinish them. Mine are in A-1 shape except for the paint being scratched here and there.
Would a flat black paint be acceptable?

[Edward J.]

Re: Corerct finish for a 70 wiper arms and blades

Steve, thats a interesting question, my 72 has the original finish on them and it almost appears to be a very dark greenish color along with the washer nozzle piping. and not at all flat black, mine have a shiney appearance, maybe it was cleaned or waxed before?and the surface seems to be of a plating not painting.

[Terry M.]

Re: Corerct finish for a 70 wiper arms and blades

It is not black phosphate. It is some weird plating I suppose because parts of them are stainless steel and that material does not like to take most coatings. If you really really want to know, I will look it up, but trust me -- it won't do you any good. It is not a common commercially available plating.

[Steve D.]

Re: Corerct finish for a 70 wiper arms and blades

Terry,
Are the arms plated as well? Do you know anybody that does refurbish them?

[Mark D.]

Re: Corerct finish for a 70 wiper arms and blades

It is a funky finish but, I thought it was just on the stainless parts such as the insert holder pictured below. These are NOS I purchased from Pete Lindahl.

I'm not sure how one would duplicate it. Kind of like the finish on original tie rod tubes.

[Terry M.]

Re: Corerct finish for a 70 wiper arms and blades

I was speaking of the arms -- and yes they are plated. I know nothing about the holders. I am sorry I didn't make that clear.

Some parts of the arms (marked with a symbol) to be black chromium to meet GM 6033-M
Other parts (marked with a different symbol) to be black sodium dichromate.

Lots of luck. Aren't you glad you asked?

Oh I almost forgot. Do you want to know how long they have to withstand the salt spray, and what the standards are for that test?
There are also standards for the reflectivity of the coating. Those are even more difficult for us non-lighting engineers to understand. It winds up as WTMI (way too much information).
Edit add: There are also specifications for how much fluid should come out of the washers at a defined pressure. You can read that int he new revised PV Manual.

Unless I miss my guess the blades are made of rubber.