Hi, I see some vendors that offer fastener kits to our cars are supplying all stainless A4. With our cars being a mix of aluminum, steel, galvanized steel and potmetal, I can't help but think that this is a really bad idea due to the galvanic corrosion that would occur... It must be false security using pretty stainless bolts, thinking that because they don't rust that it will keep the car looking beautiful and that the bolts would release easier in the future, right?
With stainless being the most noble metal of those I have mentioned above, this type of fastener would act as a cathode, accelerating the corrosive attack on whatever it is attached to... which in our cars would usually be far more cumbersome and expensive to mend or replace than a simple fastener. And, with the hardness of a stainless bolt, if the corrosion between the two metals causes it to seise up, and it either snaps or needs drilling out, it will be much more difficult than if the bolt was softer.
Ideally the metal of the fastener should be the same as whatever it is bolted to. If this is not possible due to one having to bolt different metals together, like aluminum to steel, then the bolt should be the equivalent of the more noble of the two. And, if this is not possible, then the fastener should be the most noble in the mix, but as close as possible in its electrode potential.
To what extent this is simply a theoretical problem with me being paranoid or an actul and significant problem we need to be aware of I don't know... I'm a noob when it comes to Land Rovers. In boats however, this is a significant issue as it is bobbing in an electrolyte called sea water and often is connected to land power that can spur galvanic corrosion even further... I assume that LR used positive earth for amreason.
I would really like to hear what you use where, why you use it, what your mileage is, what you would not use and why. In addition to fasteners, do you use electrical inulators such as pastes, if so which? Pastes and greases may keep out water and other electrolytes, they can seal the two metals from eacother, and they can act as a release agent. But sometimes you want thread lock agents... Nylon rings can provide insulation where steel touches aluminum, as can different type of caulking. What do you and do you not use, and why?
I am conscidering using mainly 8.8 hot galvanized bolts combined with copper grease and spring washers (nuts with nylon locking get brittle and are not really reusuable). I am also conscidering using nylon rings in some places to attach the aluminum body to the steel. As for choice of pop rivets, I have no idea... In boats we use monel, but they aremvery pricey. As for caulking or other form of insulators, I have no idea.
Please contribute.
With stainless being the most noble metal of those I have mentioned above, this type of fastener would act as a cathode, accelerating the corrosive attack on whatever it is attached to... which in our cars would usually be far more cumbersome and expensive to mend or replace than a simple fastener. And, with the hardness of a stainless bolt, if the corrosion between the two metals causes it to seise up, and it either snaps or needs drilling out, it will be much more difficult than if the bolt was softer.
Ideally the metal of the fastener should be the same as whatever it is bolted to. If this is not possible due to one having to bolt different metals together, like aluminum to steel, then the bolt should be the equivalent of the more noble of the two. And, if this is not possible, then the fastener should be the most noble in the mix, but as close as possible in its electrode potential.
To what extent this is simply a theoretical problem with me being paranoid or an actul and significant problem we need to be aware of I don't know... I'm a noob when it comes to Land Rovers. In boats however, this is a significant issue as it is bobbing in an electrolyte called sea water and often is connected to land power that can spur galvanic corrosion even further... I assume that LR used positive earth for amreason.
I would really like to hear what you use where, why you use it, what your mileage is, what you would not use and why. In addition to fasteners, do you use electrical inulators such as pastes, if so which? Pastes and greases may keep out water and other electrolytes, they can seal the two metals from eacother, and they can act as a release agent. But sometimes you want thread lock agents... Nylon rings can provide insulation where steel touches aluminum, as can different type of caulking. What do you and do you not use, and why?
I am conscidering using mainly 8.8 hot galvanized bolts combined with copper grease and spring washers (nuts with nylon locking get brittle and are not really reusuable). I am also conscidering using nylon rings in some places to attach the aluminum body to the steel. As for choice of pop rivets, I have no idea... In boats we use monel, but they aremvery pricey. As for caulking or other form of insulators, I have no idea.
Please contribute.