Jump to content

Collected listing of finishes for fasteners, brackets, and ?


Go to solution Solved by Mike A,

Recommended Posts

I'm pretty sure that if this exists here on the FAQ I'd have found it - maybe there's a reason why it doesn't that hasn't occurred to me. Or maybe it's just something that could be started?

 

I'm cleaning up under the hood, and I find myself repeatedly asking myself - I wonder if these bolts were painted body color from the factory, what the finish on the throttle linkage was originally (I've seen LOTS of parts yellow cadmium plated that really make me wonder if they were that way to start).

 

It's not that I have any illusions of having a car for Amelia Island - but if I'm going to refinish something, why not do it the way it was originally? Are there any really well documented cars that are original that can be used as reference? Or does anyone have any suggestions as to a format where this information could be archived in a logical fashion here?

 

Since that doesn't exist yet (AFAIK) any input on the finish for the "V" and "I" brackets that hold up the tii intake plenum? (I'm betting it's not the fire engine red the used spare parts came as. How about throttle linkage and the bracket it swivels on that bolts to the block?

 

Barrett

Link to post
Share on other sites
  • Solution

Under the hood, Yellow zinc for fasteners and very small steel parts, black chassis paint for large steel parts and be done with it. Can’t imagine anyone giving you a hard time about being “incorrect”. You don’t want “yellow cad”.

  • Like 2
Link to post
Share on other sites
10 hours ago, Mike A said:

Under the hood, Yellow zinc for fasteners and very small steel parts, black chassis paint for large steel parts and be done with it. Can’t imagine anyone giving you a hard time about being “incorrect”. You don’t want “yellow cad”.


+1

 

Following Mike’s plan, you’d probably have the appearance 97% correct. If you’re really nutty — that compliment has previously been tossed my way — many parts reveal the original finish in more protected areas: under bolt heads, washers, any area not exposed to 50 years of un-filtered engine compartment environment. The first photo shows the “jogged end” of my ‘76’s hood hold-down: note the yellow cadmium on the formerly protected end of the jogged end.

 

Originally, yellow cadmium was the most common. We now replace that with yellow zinc. But a few pieces, e.g., the “sheet metal” components of the headlight buckets, were originally silver cadmium, which we now routinely replace with clear zinc. The second photo shows headlight buckets re-plated to reproduce the original evidence: clear zinc sheet metal components and yellow zinc hardware.

 

But, be forewarned: replacement parts frequently had different finishes from the the original factory-installed parts. And the factory finishes were by no means carved in stone. Those hood hold-down ends I’ve shown below? Others have them in silver cadmium. Change in supplier? Maybe a change in finish. I don’t believe BMW sweated these details.

 

Painted screw and bolt heads, from the factory? Very, very rare!

 

The last photo is my ‘76, where virtually all of this stuff has been re-plated by now. 100% accurate of this car on the assembly line? I seriously doubt it. And this is a car that’s had a single owner and has four full volumes of receipts...

 

Best regards,

 

Steve

 

 

38925029-EEF0-4D00-B494-5A664A8FA640.jpeg

5928F90B-E1D2-4195-9B55-3114801905D2.jpeg

AF004C43-E7C8-4CF6-A25A-5A4940D95DCD.jpeg

  • Like 3
Link to post
Share on other sites

Steve....

I don’t know what the research revealed here on the O2 forum , but over on the 911S registry plated parts  underwent exhaustive scrutiny resulting in dispelling the myth of yellow cad for the original classic Porsche (chemical analysis). I wouldn’t be surprised if the same was found in these cars’ original fasteners. Awful hard to tell the difference visually. Nonetheless, to electroplate using cad is significantly more expensive than zinc around here.

....and that^^^, is a beautiful engine compartment

Edited by Mike A
  • Like 1
Link to post
Share on other sites
4 hours ago, Mike A said:

Steve....

I don’t know what the research revealed here on the O2 forum , but over on the 911S registry plated parts  underwent exhaustive scrutiny resulting in dispelling the myth of yellow cad for the original classic Porsche (chemical analysis). I wouldn’t be surprised if the same was found in these cars’ original fasteners. Awful hard to tell the difference visually. Nonetheless, to electroplate using cad is significantly more expensive than zinc around here.


Mike,

 

Research? 😯🤫 Uhh... yes, of course, the research!
 

I’d guess that well-heeled 911S guys have devoted far more attention and resources to metal finishes than blue-collar ‘02 guys. 😉 So that’s in favor of the conclusions published on the 911S Registry. Just to be clear, their conclusion is yellow zinc and not yellow cadmium?

 

The “analysis” here, best I can tell, relies on: (1.) a bunch of old guys, such as myself, referring to most of the “yellow-ish” plating in the sixties and seventies as “cadmium plating” — and before the Internet, misinformation was unheard of 😉; (2.) early 1960’s factory parts books, such as I have for my ‘61 Ford F-350, sometimes note the plating on parts — lots of yellow and silver cadmium were used by Ford, ca. 1961, but I have no evidence that BMW, ten years and a continent away, used cadmium to the same extent; and (3.) re-platers, such as the one I used in Atlanta for 9 years, saying, in a non-committal way “Yeah, that’s probably cadmium: it’s hard to tell.” I’d be just as happy if BMW, in the ‘60’s and ‘70’s, used zinc in lieu of cadmium. And I’d guess that BMW and Porsche used consistent methods.

 

Discussions here suggest that zinc plating is less durable than cadmium plating. I have no idea if that’s proven, or simply an opinion.

 

Best regards,

 

Steve

 

Link to post
Share on other sites

From what I have been told by reliable industrial experts , cad is superior to Zinc in a marine environment (heavy salt ) and zinc has the upper hand in atmospheric and in industrial applications. The extent to which they prevent corrosion has much to do with the thickness which is dependent on the surface roughness of the base metal. Flat is easy to measure using various methods, fastener threads nearly impossible so I am told. Other issues like galvanic action, lubricity, etc. between the two also determines which one is specified. As to what was used in the early Porsche you would think it would be cad given the atrocious German winter and heavy salt use but according to the folks over there zinc/yellow chromate was the choice. Maybe the accountants had the final say.

  • Thanks 1
Link to post
Share on other sites
58 minutes ago, Son of Marty said:

The only hardware that I can recall being painted is the hood and trunk hinge bolts and the torsion bar/strut leg bolts to make them work.

 

...And the fender washers are painted.  I strongly dislike painted fasteners and have therefor opted to run yellow zinc on those parts as well.

 

7 hours ago, Conserv said:


Those hood hold-down ends I’ve shown below? Others have them in silver cadmium. Change in supplier? Maybe a change in finish. I don’t believe BMW sweated these details.

 

38925029-EEF0-4D00-B494-5A664A8FA640.jpeg

 

 

 

I know you've heard me mention it before, but for the sake of the intent of this thread.  Peter Sliskovich (one of the old guard) swears that these little end pieces were nickle plated.  Again, change of finish were fairly frequent throughout the 02 production,  so who knows for how long this was the case.  I agree there isn't a magic formula on these cars.

  • Like 3
Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.



×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.