Topic: 1968 San Jose GT 390 Fastback Zinc & Cad finishes

[bullitt68]

Just checking to confirm the correct finish on the front turn signal buckets. I had them Silver zinc plated, but was told that they should be gold cad after I platted them

[ruppstang]

They should be zinc dichromate.

[bullitt68]

They should be zinc dichromate.

Great thanks. I don't think these are Zinc dichromate. My that that there is a difference understanding from dichromate and regular silver zinc plating

[Coralsnake]

zinc dichromate is the translucent gold 🌈 rainbow

Cad and zinc are often used interchangeably, however think of cad as a hard plate and zinc as a wash

[bullitt68]

zinc dichromate is the translucent gold 🌈 rainbow

Cad and zinc are often used interchangeably, however think of cad as a hard plate and zinc as a wash

Oh great thanks. Co zinc can have a gold color to it. For some reason I thought zinc referred to the color as in zinc phosphate being the lighter color and manganese being the darker of the two. As far as I know there are not many parts that get the zinc dichromate on my car other that the front lower turn signal buckets and the seat belt hold down bolts. Am I missing anything.

[Bob Gaines]

FYI the part has to be plated the Zinc silver first prior to going into the zinc dichromate wash/dip . The Zinc dichromate needs the base of zinc for it to stick to . No zinc no stick. If you wear off or wash off the zinc dichromate with acid etc it will be silver underneath.

[jwc66k]

In the hi-tech environment, following the philosophy of "make it simple enough for an engineer to understand, and you'll have no problem", plating was referred to by its color, silver (or clear) zinc, gold zinc, black zinc. The same applied to cad plating, although cad plating was not commonly used in the aerospace world This terminology was used by almost all the companies in Silicon Valley during the 60's on.
If you download the "Mustang Hardware Spreadsheet 67-68", and scan down the FIN column (you can sort by that column as well), finish code "-S36", is for gold zinc. This will give you the hardware items. As to parts, Ford used the gold zinc finish in many electrical applications (red colored plating was for special torquing). Electrical items you encounted would be the basis for questions. Exceptions are normal.
Jim

[bullitt68]

FYI the part has to be plated the Zinc silver first prior to going into the zinc dichromate wash/dip . The Zinc dichromate needs the base of zinc for it to stick to . No zinc no stick. If you wear off or wash off the zinc dichromate with acid etc it will be silver underneath.

Great. Thanks Bob. I guess my platter missed a step!

[bullitt68]

In the hi-tech environment, following the philosophy of "make it simple enough for an engineer to understand, and you'll have no problem", plating was referred to by its color, silver (or clear) zinc, gold zinc, black zinc. The same applied to cad plating, although cad plating was not commonly used in the aerospace world This terminology was used by almost all the companies in Silicon Valley during the 60's on.
If you download the "Mustang Hardware Spreadsheet 67-68", and scan down the FIN column (you can sort by that column as well), finish code "-S36", is for gold zinc. This will give you the hardware items. As to parts, Ford used the gold zinc finish in many electrical applications (red colored plating was for special torquing). Electrical items you encounted would be the basis for questions. Exceptions are normal.
Jim

Great thanks Jim. Will do that

[bullitt68]

In the hi-tech environment, following the philosophy of "make it simple enough for an engineer to understand, and you'll have no problem", plating was referred to by its color, silver (or clear) zinc, gold zinc, black zinc. The same applied to cad plating, although cad plating was not commonly used in the aerospace world This terminology was used by almost all the companies in Silicon Valley during the 60's on.
If you download the "Mustang Hardware Spreadsheet 67-68", and scan down the FIN column (you can sort by that column as well), finish code "-S36", is for gold zinc. This will give you the hardware items. As to parts, Ford used the gold zinc finish in many electrical applications (red colored plating was for special torquing). Electrical items you encounted would be the basis for questions. Exceptions are normal.
Jim

I downloaded the spread sheet. Very comprehensive indeed a great reference tool. So I take it that the only actual parts other than electrical and fasteners that get the zinc dichromate are the lower front signal buckets. I didn't see any other parts that came off my car that were finished that way. Actually the signal buckets looked clear/silver zinc when removed. Most likely the gold faded with time

[J_Speegle]

............. As far as I know there are not many parts that get the zinc dichromate on my car other that the front lower turn signal buckets and the seat belt hold down bolts. Am I missing anything.

Off he top of my head - and surely there are more - believe you can add

- Some of the carb linkage and hardware
- Door latch parts
- Door latch post spacers
- Smaller screws used for mounting and grounding electrical items
- Interior latch of the trunk latch and other interior parts of the latch
- Door handle mechanism's ?
- Mounting bracket for the rear brake line junction to rearend housing
- Drum brake shoe anchors
- Interior drum brake hardware
- Brake bleeders
- Mounting bracket for the front brake junction/routing block
- Front marker light retainers?
- Some of the Thermactor clamps and you can use it as a base for recoloring the T

Its a quick start

[Bob Gaines]

I downloaded the spread sheet. Very comprehensive indeed a great reference tool. So I take it that the only actual parts other than electrical and fasteners that get the zinc dichromate are the lower front signal buckets. I didn't see any other parts that came off my car that were finished that way. Actually the signal buckets looked clear/silver zinc when removed. Most likely the gold faded with time

Like I mentioned before ,when the gold wears off the underlying surface is silver in appearance regardless of if a nut,bolt or exterior surface of a part. The remaining color in many instances can fool one into thinking it was originally one finish when in fact it was another. Thousands of parts on these cars each with it's own story.

[bullitt68]

Off he top of my head - and surely there are more - believe you can add

- Some of the carb linkage and hardware
- Door latch parts
- Door latch post spacers
- Smaller screws used for mounting and grounding electrical items
- Interior latch of the trunk latch and other interior parts of the latch
- Door handle mechanism's ?
- Mounting bracket for the rear brake line junction to rearend housing
- Drum brake shoe anchors
- Interior drum brake hardware
- Brake bleeders
- Mounting bracket for the front brake junction/routing block
- Front marker light retainers?
- Some of the Thermactor clamps and you can use it as a base for recoloring the T

Its a quick start

Great thanks Jeff appreciate it. That is a great start

[bullitt68]

Like I mentioned before ,when the gold wears off the underlying surface is silver in appearance regardless of if a nut,bolt or exterior surface of a part. The remaining color in many instances can fool one into thinking it was originally one finish when in fact it was another. Thousands of parts on these cars each with it's own story.

Very true Bob great point. Glad I asked as I had the buckets zinc'd to how they looked not how they should be. Will get them done correctly now. I wanted to be sure if there was anything else I could send out as a batch at the same time. There is a local place that does what they call yellow zinc, which is ok for very small parts, but for larger parts I send them out to get done properly and the more stuff I send the better to save on shipping

[Bob Gaines]

Very true Bob great point. Glad I asked as I had the buckets zinc'd to how they looked not how they should be. Will get them done correctly now. I wanted to be sure if there was anything else I could send out as a batch at the same time. There is a local place that does what they call yellow zinc, which is ok for very small parts, but for larger parts I send them out to get done properly and the more stuff I send the better to save on shipping

yellow zinc is typically zinc dichromate. You don’t want to do yellow cad /cad gold gold or expect a non factory finish.