Decklid and hood latches

[Shaun 69 E]

I'm plating several customers' latch sets now, some original, some horribly replated. I've had 20+ latches from cars I've parted out, owned etc. And I have one lightly used NOS front bottom catch for reference. Is there any documentation on when Porsche switched over from blue chromate zinc to yellow chromate zinc on the rear catches?

For the front, I'm doing a special process blue chromate zinc for the upper and lower latch bodies, yellow zinc bottom catch return spring and cable locking bolt. Upper latch will have a blue chromate zinc spring.

Any ideas on the rear? I have a mix of blue chromate zinc and yellow chromate zinc latches.

Any thoughts on original colors are welcome.

[edmayo]

I'm not going to try and get involved in the color discussion, but in case you don't already know, don't send the spring cups to the platers,,,,they dissappear!

[robmog]

My 72 had blue chromate build date 7/72.

[Shaun 69 E]

I'm not going to try and get involved in the color discussion, but in case you don't already know, don't send the spring cups to the platers,,,,they dissappear!

Hi Ed,

I'm guessing you must be the same Ed Mayo on the PCA Technical Committee. I asked a question a while ago on PCA.org about Porsche's timing on the changeover from cadmium to zinc plating. You must get deluged with email. Can you point me in the right direction for an answer on that subject? Someone at Porsche must know about this. And I imagine the answer to this question here as well.

Good call on the potmetal cups, I found that out years ago much to my dismay. I plan on casting new ones in 2016, many that I get in are in very bad shape.

Thank you, appreciate your help!

Shaun

[Shaun 69 E]

My 72 had blue chromate build date 7/72.

Thank you Bob, hope you are well!

[chiroracer]

Instead of casting would machining be easier for the spring cups?

[Shaun 69 E]

It would be easier but a lot more expensive, and more importantly (to me anyway), not original. Plus I get to learn how to make a mold and cast pot metal; that's got to be fun.

[edmayo]

Yep,,,guilty at both places!! I don't have the definitive information you're looking for, and I doubt anyone at Porsche A.G. would know or care! Mark Smedley on this board, and Paul Risenger have both done their own research and found that it all comes down to D.I. N. standards and when they were applied. If I remember correctly (Mark jump in here) cad was out in the late fifties early sixties. Due to D.I.N. standards again the zinc plating generally changed from silver (clear) to yellow in the mid-sixties. Generally 67 911s started having more yellow hardware. Realize there often are no definitive cut-off dates since hardware was changed over as the bins were depleted and then replenished. And the guy screwing the engine together didn't really care if both were on the same engine, they were building cars as a business,,,,not for us concour judges. As to the latches in question, I just consider them as clear zinc, as to tint, that may be more a 'batch' situation than anything that was planned.

[mshaver51]

this isn't much help, but i have SWB project, and i have asked the same question re: yellow or clear plating on latches. the best answer that i received was that SWB was all clear zinc. no one provided me with any documentation, however.

(i was also told that the yellow zinc began in '73, but i never asked for documentation.)

[smedley]

Ed has given a very good synopsis of the fastener industry standards. Porsche just used what they were supplied. By '66-'67 virtually all the fasteners on the chassis and drive train were yellow Zinc....the wierd exception is the lid latch mechanisms and hardware which were clear (silver) zinc through '73. Amongst those of us sick enough to study and catalog cars we have disassembled, inspected, and judged the remaining debate is the the plating on the springs on the latch pins, front and rear....I have maintained that most are yellow, but others say silver......I note that in the photos on this thread there are yellow and silver springs....so the debate will go on.........but!.... the latches and their fasteners were definately silver zinc. If one wants to take this even further....my experience with multiple cars from '66 through '71 has silver zinc on the bolts fastening the lids to the hinges.....those started going yellow sometime in '72. Also, one has to be careful about the "dogma" of the parts manuals.....I have a set of dog eared original '67 parts books that list the M8 bolts for the rear bumperette horns (horn to body) as hex head....I have personally inspected at least five stone original '67 cars ( and many later) with allen head bolts in that position! Porsche never specified yellow versus silver zinc. That was a DIN fastener industry thing. They DID specify zinc ("verz") versus black oxide ("bos") in certain areas. This probably won't clear up anything...we still have people using "yellow and silver cad" on this forum which exists but disappeared from the fastener industry in the mid 50s!!