Topic: Wiper motor ground screw to cowl question - 69 Dearborn

[bjf1992]

What finish should the ground screw for the wiper motor be?

April 2nd 1969 Dearborn car.

[Bob Gaines]

What finish should the ground screw for the wiper motor be?

April 2nd 1969 Dearborn car.

Typically S36 (zinc dichromate gold ). Many times ground fasteners were the zinc dichromate more so in the later years 68-70 then the earlier years 65-67 . It is common to see things have to do with electrical  the zinc dichromate. I can't comment on other years which are outside my field of study.

[J_Speegle]

Sorry for the blurry picture. Allot of the exposed screws after all these years have lost the goldish tint they originally had

[jwc66k]

Typically S36 (zinc dichromate gold ). Many times ground fasteners were the zinc dichromate more so in the later years 68-70 then the earlier years 65-67 . It is common to see things have to do with electrical  the zinc dichromate. I can't comment on other years which are outside my field of study.

One train of thought is the gold zinc is for better conductivity. Another train is to identify a ground point. Also the difference in Ford specification between -S8 clear zinc and -S36 gold zinc is the gold must withstand a 72 hour salt spray test vs. 24 for clear zinc.
Kim

[Bob Gaines]

To add to the discussion the zinc dichromate goes over the zinc silver . If you rub off the zinc dichromate it is silver underneath. It is interesting to note that the zinc dichromate will not plate over bare steel . It has to have a zinc base to stick or plate. That is where the Zinc silver comes in . In the case of a carburetor ,the casting has a lot of zinc in it which allows the zinc dichromate to plate although in a slightly different way which gives a slightly different appearance. The Zinc silver with a top layer of zinc dichromate no doubt adds corrosion resistance although not much I suspect.

[J_Speegle]

Not sure if I would refer to Dichromate as a "plating" but rather a dye

In any case not sure if we need to understand what the plating or dye does if we're restoring cars but some like to understand every detail and find their enjoyment there

[Bob Gaines]

Not sure if I would refer to Dichromate as a "plating" but rather a dye

In any case not sure if we need to understand what the plating or dye does if we're restoring cars but some like to understand every detail and find their enjoyment there

I believe that is the typical referred to term for the process even though it is a non electricity applied dye like process. It is electrically conductive however. I guess a dye much like a paint isn't typically considered to be electrically conductive.

[bjf1992]

Thanks for the help! I was surprised this piece wasn't included
In the AMK wiper kit. I ordered 8 of them. Now I can do my car and 7 others