Copper "grease" on bolts

[gudjeon]

When I made my own wiring system, I grounded every panel and made one large common ground to eliminate any potential electrical problems. A larger main ground is seen, as mentioned on composite construction such as planes and boats. Will this help with galvanitic corrosion? I'll let you know in another 50 years.

[printjunky]

and galvanize everything!

http://www.freepatentsonline.com/6165630.html

[kevkon]

And in doing so it becomes obvious that galvanic corrosion between dissimilar metals is the least of the concerns with a Series truck. The big killer is corrosion of the metal frame and bulkhead. Keep those protected and call it a day.

[thixon]

Time line.....Look at your tuck. Look at other peoples trucks.

There is already 60 or so years worth of observational data that can be used to predict how long it will take for things to start coming apart.

If anyone here is that worried about it, then coat the fasteners, parkerize, or maybe plate with gold? You could always use nylon fasteners.

[jac04]

... does anyone have a timeline for galvanic corrosion on any of these parts? ...

Check out PeterK's post above. Looks like several years. Maybe he can provide a little more feedback on the exact timeline.

[amcordo]

Sorry, Tony. I never said the aluminum was going to turn to dust. In response to someone pointing out that galvanic corrosion will still occurr with stainless fasteners on aluminum, you stated "Already accounted for. That's why I use nylon washers on either side of my normal washers." You seemed to be stating that you were using the nylon washers because you knew about galvanic corrosion and were actually trying to do something to stop it. I was simply pointing out a key flaw in your reasoning.

Now, all the Rovers I have restored have utilized a lot of stainless hardware with no attempt to isolate it from the aluminum. I actually drove one of the vehicles I mechanically restored (a 69 SWB) through a few Maine winters with absolutely no signs of galvanic corrosion issues. The vehicle even had very thin original paint, so the aluminum wasn't well protected. However, the vehicle had a galvanized chassis which was left bare. Because zinc is more active than aluminum, the zinc on the chassis becomes the sacrificial anode.

I know you are "rust proofing" your vehicle by galvanizing a bunch of stuff, which is great. I know you are not galvanizing the chassis. Have you thought about installing sacrificial zinc anodes on the chassis?

Well eventually I'll upgrade to a galvanized chasis - but it's a ways off for a number of reasons. Let me take a step back and ask this: does anyone have a timeline for galvanic corrosion on any of these parts? Do I really need to worry about sacrificial anodes? Keep in mind my primary enemy no matter what has to be your run-of-the-mill salty roads in the winter corrosion.

It's starting to sound like, at least for me, the tradeoff I need to make is either resisting salt spray or resisting galv... blah blah corrosion.

I demand both.

Now I just need to find more plastic/fiberglass parts and just turn the whole car into a modern vehicle...

[SafeAirOne]

Mark, Not to put too fine a point on it, but the only difference between 304 and 316 is Moly(bdenum) and they both have the same physical properties (Yield, UTS, E2" and RA) and will gall equally.

I think I may have got the types of stainless wrong in my example--Trying to do it from memory, as I'm not at the shop. My experience with the galling problem is that I was putting a bunch of 1/4-20 SS nyloc nuts on 1/4-20 SS bolts and was having many of them jam halfway tight. I went back to Fastenal and asked them what was going on, and they explained the galling issue and gave me their other stainless alloy nuts--Probably 18-8. Either way, I've used hundreds of these nuts in combination with the different alloy bolts and haven't even had a hint of galling since. Galling problem solved.

[JackIIA]

here's a neat little website that i think helps to put the different anodic/cathodic stuff in relative perspective. i leave it to the engineers to understand the details (seems like every rover owner on the site with the exception of me is either an EE or an ME - seriously. no poets out there?).

but what's kind of cool is the hierarchy of sacrificial metals relative to one another.

http://www.eaa1000.av.org/technicl/corrosion/galvanic.htm

[PeterK]

Joining in late,

I went all out on a 109 I built several years back.
Absoloutly every steel part was galvanized.
Axles POR-15
Every fastener practical was stainless
Every connection loaded with copper grease
Tub, seatbox, floors, footwells Rhino Lined
Loads of aluminium rivet nuts, with SS machine screws
All body rivits replaced with SS machine screws and SS nylocks.

What I learned.

Any connection where a galvanized part was present, there was no corrosion whatsoever with SS.

A connection between two aluminium parts with a SS fastener started to show signs of corrosian after several years, paint blistering, white dust.

There are very few such connections but it was universal.

Envioronment is daily driven work truck in coastal Nova Scotia, LOTS of salt year round.

Now I use cheap hot dipped galvanized nuts and bolts in many locations.
SS where it seems appropriate.
Genuine aluminium rivets

Cheers

Peter Knowles

[jac04]

... but I feel like maybe you haven't tried it much on your rover(s)... You can tell me it'll turn to dust all you want...

Sorry, Tony. I never said the aluminum was going to turn to dust. In response to someone pointing out that galvanic corrosion will still occurr with stainless fasteners on aluminum, you stated "Already accounted for. That's why I use nylon washers on either side of my normal washers." You seemed to be stating that you were using the nylon washers because you knew about galvanic corrosion and were actually trying to do something to stop it. I was simply pointing out a key flaw in your reasoning.

Now, all the Rovers I have restored have utilized a lot of stainless hardware with no attempt to isolate it from the aluminum. I actually drove one of the vehicles I mechanically restored (a 69 SWB) through a few Maine winters with absolutely no signs of galvanic corrosion issues. The vehicle even had very thin original paint, so the aluminum wasn't well protected. However, the vehicle had a galvanized chassis which was left bare. Because zinc is more active than aluminum, the zinc on the chassis becomes the sacrificial anode.

I know you are "rust proofing" your vehicle by galvanizing a bunch of stuff, which is great. I know you are not galvanizing the chassis. Have you thought about installing sacrificial zinc anodes on the chassis?

[printjunky]

(In the pro audio world again) Similar to 'star-grounding" a guitar amp.

[Terrys]

Land Rover may have figured it was a good way to save money, but it never made much sense to me why they never ran a ground wire through the chassis harness to the rear of the truck, relying instead on the body being the return leg for all the rear lights. The closest point to the lights, where the aluminum tub meets the steel frame, is the 5 tabs along the top of the rear crossmember. Ever notice how those 5 spots are always eaten up? Ever notice when you take one of the rear light bases off the truck that it's frequently corroded around the screw holes. Coincidence?
Galvanic action is greatly increased in the presence of electrical currents, so running a wire, oh, say a piece of 12ga. wire, from the point where the NEG battery cable attaches to the frame, through the chassis, same route the chassis harness takes, to the rear, and to each individual lamp base, may greatly reduce the tub corrosion. I think that might be a little easier than trying to electrically insulate every fastener (and the 2 parts the fastener is fastening).
I'm sure all of you who have been around boats have noticed the heavy green 8 ga wire that goes to every through-hull fitting, terminating at the engine. Long common practice on boats is to use sacrificial zink annodes on the rudders and prop shafts.

[printjunky]

Quick aside on insulating washers, in recording studios, we use nylon 'shoulder washers' (washer with a bushing attached, basically) when hanging gear in racks, to ensure, or at least maximize electrical isolation, so as to eliminate the hum from various grounding issues. If it's not going to hum, it's not going to go galvanic. (Though I suppose it would while (if) the electrolyte bridges any gap between the parts.) As previously stated, I would consider this anti-galvanic overkill. But there might be some extreme Rover owners out there to whom no length is going too far. (is that the Gentle Sarcasm Smilie?)

[amcordo]

Again, not really. Please don't take this the wrong way, but you don't fully understand galvanic corrosion. The physical electrical connection between the metals is not where you see the galvanic corrosion. It is the surfaces of the metal that are exposed to the electrolytic solution.

Anyhow, I guess I'm getting a little too technical on the subject, so I'll just drop it.

True about not understanding the physics and chemistry behind the corrosion - but I feel like maybe you haven't tried it much on your rover(s)... You can tell me it'll turn to dust all you want and I'll tell you this:

I'm just going off real-world experience now. As I said earlier, the nylon washers and SS hardware the PO put on ten years ago haven't caused any aluminum to turn to dust, so it is what it is. Just wanted to share my experience with everyone so that they'd have an option if they wanted to move my route towards a rust-resistant rover (YAY SS and Galvanized steel!)

[109 Pretender]

Carroll Smith has a great book on fastener do's and don'ts although it's geared more for racers. A lot of good points have been brought out in this thread and anti-seize is very good for fasteners that you intend/expect to remove again - especially if those fasteners will be exposed to road grime and moisture like suspension bolts. I'd personally never recommend s/s for any stressed connections that are critical like suspension bolts. Absolutely true that reduced friction will affect torque so compensate as necessary or install as manual indicates. (If you use ARP rod bolts they will come with special lube and a much higher torque setting because they have calculated for the reduced friction imparted by the lube). Personally, I used s/s for all little screws like the window seals because they work better in that application. I also like the looks of s/s for body fasteners because they won't surface corrode and are largely exposed - but it's not original and that can be an important consideration for some folks.

Let's not forget that our vehicles usually had a hard life, were seldom washed and maybe even covered in decades worth of mud - in other words, the worst case scenerio for electrolysis to start. And yet, by and large the vehicles survived. Now that the vehicles are in the hands of caring owners I expect all our Rover's to have another 40 years or so left in them because we try to do correct repairs, keep 'em reasonably clean, and we are aware of the problematic issues of alum./steel combos. Just keeping things clean, insulating w/paint and nylon washers where possible, and vigilant watch for corrosion potential will provide more dividends than just about anything else. Remember, electrolysis requires more than dissimiliar metal contact - it requires a moisture conductor with ionic content. Dirt, mud, etc along with water provides the vehicle for the conduction process to begin.
So give the old girl a bath now and then and pay attention to the areas that collect the grime!

Cheers!