original bolt finish

For those who obsess about exactly how their 356 left the factory!
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Chris Cullin
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original bolt finish

#1 Post by Chris Cullin »

Hi all, I am returning member after 20 yrs absence. Earlier I had a T5 coupe and an SC cab and rebuilt and finished the engines to original spec. now I have a C coupe that been sitting for 20 years and Im working on the brakes and suspension. I want to re-plate nuts and bolts to original finish but cannot find any lists of finishes. Does anyone know if there is such a list or if all nuts & bolts were finished in either cad/zinc or blackended or were some unfinished?
356 T5 coupe (gone)
356 SC cab (gone)
356 C coupe
VW T3/Vanagon camper
VW T3 transporter
MG TF1500

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Vic Skirmants
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Re: original bolt finish

#2 Post by Vic Skirmants »

Welcome aboard, Chris. I'm sure someone will answer your question shortly.

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Dennis Vogel
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Re: original bolt finish

#3 Post by Dennis Vogel »

Chris Cullin wrote: Tue Sep 27, 2022 6:47 am Hi all, I am returning member after 20 yrs absence. Earlier I had a T5 coupe and an SC cab and rebuilt and finished the engines to original spec. now I have a C coupe that been sitting for 20 years and Im working on the brakes and suspension. I want to re-plate nuts and bolts to original finish but cannot find any lists of finishes. Does anyone know if there is such a list or if all nuts & bolts were finished in either cad/zinc or blackended or were some unfinished?
I went through this exercise a couple years ago. Long story short, be prepared for some ambiguity. The older parts catalog will tell you the finish of some things. Others you will have to discern based on the year. With a C, I think you may be getting into the 912 era where some things started being produced with a yellow / gold finish?

As a general rule of thumb for our T5, right or wrong, I landed on zinc (clear / silver) is probably closest to original for most things. If you prefer, you can still get cad done by folks like Van Nuys Plating. Cad Type I (clear) Class II (0.0003 inch) plating

There is a thread on the Early 911S Registry forum that sounds pretty convincing and applicable to all Porsche’s regardless of model.
  • Sometime in 1966 the transition from clear (silver) to yellow was made
  • Zinc was used rather than cadmium plating
  • Chromate or phosphate was used (giving it a yellow tint) in order to improve resistance to ‘white rust’
  • These were driven by DIN standards, not unique to Porsche
There are people on this forum that have forgotten more than I will ever know, but this is what I can offer from my own research.
1960 356 S90 Sunroof Coupe
2014 Carrera S

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Mike Wilson
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Re: original bolt finish

#4 Post by Mike Wilson »

Welcome back, Chris. I just checked the C parts manual in the brake section, 3/8 C. It shows the different hardware. Some are marked galvanized zinc, some phr (phosphate) and others in nomenclature I am not aware of. Bostik is one and verz the other. When I did my brake, steering and suspension hardware, I went with black zinc.

Mike
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Lomita, CA
'63 B coupe

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Doug McDonnell
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Re: original bolt finish

#5 Post by Doug McDonnell »

Nice old argument about the brake calipers: viewtopic.php?f=1&t=6722 My take is calipers gold either cad or zinc as I have never seen a chemical analysis. Caliper through bolts a black phosphate. Today yellow zinc would be easier and much cheaper. The bracket on the rear axel that holds the brake lines are yellow CAD the only place on a C/SC that I know of that was yellow Cad. Concensus on most other fasteners and linkages is Industrial clear zinc coating. See Joris's comment here: viewtopic.php?f=1&t=6722
Last edited by Doug McDonnell on Sun Oct 02, 2022 2:00 am, edited 2 times in total.
1965 356C 2000 BMW 740i Sport 1967 Honda CL77 There is never enough time to do it right, but always enough time to do it over.

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Doug McDonnell
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Re: original bolt finish

#6 Post by Doug McDonnell »

For a nice article go to Registry Magazine 38-5 and read Bruce Smith's "Plating at Home" article To find the article from the home page hoover on technical click on dropdown menu and click on document search. Then click on Magazine and Magazine article then click on Magazine article-pdf then on V30-39 then click on V38 and on the right will be all the articles. Bruce's article is the 26th I think. Another possibly easier way is to hoover over Media Center then click on Magazines and on the right side you will see magazine archive and click on Volume 46-31 then scroll down to volume 38-5 click on it and scroll down to the article on page 76. Oh and I forgot Welcome to the Registry !!!
1965 356C 2000 BMW 740i Sport 1967 Honda CL77 There is never enough time to do it right, but always enough time to do it over.

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Chris Cullin
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Re: original bolt finish

#7 Post by Chris Cullin »

thanks all for you guidance. I'll follow these leads through. The parts catalog I have has 'remarks' but no index what they mean, for example the calipers have remarks of /V/R and /V/L?
356 T5 coupe (gone)
356 SC cab (gone)
356 C coupe
VW T3/Vanagon camper
VW T3 transporter
MG TF1500

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Chris Cullin
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Re: original bolt finish

#8 Post by Chris Cullin »

oh - I just discovered the parts catalog on the 356registry site - nice! This gives me something to work through as a guide :)
356 T5 coupe (gone)
356 SC cab (gone)
356 C coupe
VW T3/Vanagon camper
VW T3 transporter
MG TF1500

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Dennis Vogel
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Re: original bolt finish

#9 Post by Dennis Vogel »

Chris Cullin wrote: Sun Oct 02, 2022 3:17 am thanks all for you guidance. I'll follow these leads through. The parts catalog I have has 'remarks' but no index what they mean, for example the calipers have remarks of /V/R and /V/L?
The first few pages of the catalog should include a legend:
  • /V = front
  • /H = Rear
  • /L = Left
  • /R = Right
Other letters are sometimes country codes (e.g. CH is Switzerland)
1960 356 S90 Sunroof Coupe
2014 Carrera S

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John Hearn
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Re: original bolt finish

#10 Post by John Hearn »

V = Vorderseite / Front
R = Rückseite / Rear
L = Links / Left
R = Rechts / Right
KTF
John

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Re: original bolt finish

#11 Post by DaveErickson »

This topic has come up several times in the past. I have an Excel spreadsheet copied in 2016 from another thread that is quite extensive. I've attached it below.
Porsche%20Nuts%20and%20Bolts%20%282%29.xls
(47.5 KiB) Downloaded 59 times

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Chris Cullin
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Re: original bolt finish

#12 Post by Chris Cullin »

the legend and spreadsheet are very helpful. I started creating a spreadsheet from the parts catalog and this will save me some trouble - although I will cross-check as I can't help myself.
356 T5 coupe (gone)
356 SC cab (gone)
356 C coupe
VW T3/Vanagon camper
VW T3 transporter
MG TF1500

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