j.kenzie@sbcglobal.net

Good morning,
I live in the rust belt, and for several years I needed to drive and park my 928 outside in the Winter. I'm in the process of redoing my motor mounts after 10 years, and some of the fasteners involved look very rusty. I could of course clean and wire brush them and they would look OK for a while. I was considering just buying new grade 10.9 bolts (for the structural fasteners) with new zine plating. Maybe they'd stay rust free for a while. I no longer expose the car to salt or Winter conditions.
What do you think?
Thanks,
Dave

Mrmerlin

Call 928 INTL and buy used fasteners, better than new and costs less and they will be the right stuff
NOTE they have buckets of the fasteners that have good finishes on them, the rusty stuff they throw away

linderpat

All things considered, including the cost of your time, and the inexpensive nature of fasteners, I would replace them. Sometimes I clean up a mildly corroded fastener with a little wire brush, but usually I just get new. They do not cost much, and you get piece of mind too. Old rusty fasteners, even if cleaned up, can fail.

drooman

https://www.belmetric.com/?gclid=Cj0...UaAjenEALw_wcB

homan

yep just placed another orderwith belmetric you can get the original gold zinc, I sand blasted all my bolts primed and painted black and said F it out with the old in with the new. working on the rear part of the car now with the bigger longer bolts ended up being $125 for bolts, washers and most nuts, even found those round clips for the rear muff heat shield don't know what they look like though just ordered fri afternoon oh and they ship quickly

davek9

Once you redo them, coat all exposed (non-painted) metal with WD40 or similar rust / moisture protestant, you will find they will live longer rust & corrosion free even outside.
Metal loves to be oiled

dr bob

The original stuff was yellow cad electroplated. Yellow zinc is the cosmetic but poor functional replacement that's more readily available, after cadmium made it onto some EPA watch lists. There are a few places that still do good cad plating, associated with the aircraft industry mostly. That's why Mrmerlin proposes finding good used original fasteners from 928 International. They tend to be harvested from SoCal cars that have never seen salt or even much rain during their lives.

Wisconsin Joe

#1 - Be very careful wire brushing cad plated fasteners. The dust is toxic.

#2 - Fasteners, even the 'good ones' are cheap compared to the time and effort of getting them off when they are in rough shape.

#3 - Some situations (rod caps for example) require new fasteners every time. Some applications (airplanes are one) require new fasteners for many situations.

Short summary:
When in doubt, throw them out (or at least into the 'scrap steel' barrel).

worf928

I believed this to be true for a long long time. However, recently, conversations with folks that do plating for a living has made me doubt this. According to 'them' Porsche stopped cad plating in the early 80's and that all of the hardware that we say is 'cad' plating is actually just really-good yellow-choromated zinc. I've also now seen with my own eyes, the outcome of 'standard' cad plating, different zinc processes, and 'carefully-prepared' cad plating. I also spent non-trivial time on teh int3rw3bs trying to separate truth from fiction.

I don't know what the truth is. However, I'm not willing to bet anything important anymore that our bits-and-pieces were cad plated. Certainly the processes for plating have changed due to The Environment and today's yellow-zinc may not be nearly as good as Last Century's yellow-zinc.

On the OP's subject:
Some number of the fasteners are pretty-unique to Porsche(*) (or the time period) and can't be replaced by those you find at the hardware store (or belmetric.) If you need to replace those you have the following choices: used from 928 International, used from some other source, or new from Porsche. In any case, new fasteners from Porsche may not be even yellow-zinc. They may be 'plain' zinc or even unplated. In some cases they will not be anything like the fastener originally installed (flange nuts instead of conical locking nuts come to mind.)

New Porsches have a lot of fasteners on them that rust almost instantly. Kinda sucks that.

*
Bolts, screws with captive washers
Thin/Shallow-head Alan bolts
Some of the extra-thick or extra-large washers.
(And probably lots of others that slip my mind right now.)

Also, there are a bunch of places where it is more cost- and time-effective to replace cruddy OE fasteners with functionally-identical non-OE fasteners. For example, many of the bolts you touch when you do a timing belt are originally the captive washer type. You can replace these with new yellow zinc bolts and loose washers for a couple of bucks every 6-ish years when you do your belt. The yellow zinc in those locations will last fine for 6 years (no salt!) and replacing them every six years will be cheaper than getting OE bolts re-plated that will last through 2 or more timing belt cycles. It all depends upon how 'cheap' you are or how ****-retentive you are.

NoVector

Quote:

Originally Posted by davek9

Once you redo them, coat all exposed (non-painted) metal with WD40 or similar rust / moisture protestant...

+1 Someone mentioned Fluid Film here on Rennlist a couple years ago and I decided to give it a try. So far, I'm very happy with the result. I did the top end refresh 2 years ago and re-zinc'd everything and this is how it still looks today. Keep in mind this was in Germany with high humidity/rain all year long. There were times in the winter when the car was stored in the garage that the engine would be covered in dew. The "zincing" was with a home zinc plating kit; so, I attribute the yellow (and zinc) longevity to fluid film.

The Forgotten On

I would stick with cad plating. It lasts an eternity here in SoCal. Most of the original fasteners on my 81 don't have any rust or corrosion on them and are still yellow.

I'm going to have many replated when I get farther along in my "euro hybrid" build. But many I can just clean off and they look new all these years later.

Mark Anderson

We do offer used hardware at $2 per pound. No guarantees what you will get but if you are local you can pick it out.

BrianG

We have a local industrial plater who is a motorcycle restoration enthusiast will do both cad and zinc plating. He recommends cad as tougher for fasteners and other wear considerations. As stated above, either can be "clear" (silver) or "yellow". I'm going to send in a few bits to see how it turns out.

KenRudd

I realize its may not be a popular option, but on hardware that is not strength or torque critical, I often replace with stainless where appropriate. For example, all my hose clamps are NORMA stainless. Yes, they don't have that cool OE yellow look now, but they WILL look just as good in a few years, no rust, no pitting.

KenRudd