Body work... bondo question

rust is infact an electrochemical reaction. some boats have blocks of zinc bolted to them to prevent corrosion, as zinc has a higher affinity for oxidization. this is called cathodic (not catholic) protection. it, like galvanizing, protects the metal by "stealing" away the slight electric charge and itself corroding. anyways, cut out the metal and weld in new stuff. soon as i steal the girlfriends camera i'm gonna put together a how-to on bodywork welding so you guys can stop stuffing your cars full of bondo.

Also, wont a car not rust without salt? I remember reading about a car company that stopped there US sales hope because the cars would rust sitting on the docks. Also, I've seen Honda daily drivers in Long Island, NY where i'm from and the cars do not rust. I guess up where I am the grade or amount of salt must differ from Long Island.

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salt turns ordinary water into an electrolyte, basically meaning it's now very good at conducting current. pure water is actually a poor electrolyte, it's all the dissolved crap and ions in solution that make it so... salt just makes it easier for the oxygen in the water to find the iron in your car and rip it apart into oxides. your car will still rust without salt, just more slowly. the best way to prevent rust is to wash off the salt and mud, and seal any leaks that turn your floor pan into a lake.

In my experience with bodywork, you should use fiberglass and then bondo. If you do what was suggested above, with "forming" the panel with bondo alone? Not a good idea. Fiberglass is much more adhesive than bondo from what I've dealt with. Stronger as well. It does make you itch if you don't cover up though...lol Just my 2 cents but i guarantee that it will last longer than straight bondo. (btw no offense to whoever suggested forming w/ bondo!) Bondo is good, but not in excessive amounts.

Not too bad of an idea. Bondo should NOT be put on thick. If you have to, fiberglass under it but fiberglass is not water proof so it will rust back through but from the back side. Aluminum bondo is water proof but it’s just like regular bondo, it can’t be put on thick.


Zach

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Originally Posted by gp02a0083

por-15 is great stuff , i used it with my olds 442 and its great stuff this stuff WILL STOP rust i even have the frame from my other car practially dipped in it
if u put this stuff on a non rusted out 3gee hell it will last forever

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that was tested against the eastwood companys rust preventive product,and the eastwood product won hands down .it's called rust encapulator www.eastwood.com as far as preventing rust from coming back after taking a panel to bare metal,you have to use a self etching primer,which you can get in a spray can,it's not cheap,nappa sells one from duplicolor,this etches into the metal and helps prevent the rust from coming back.you put regular primer over this. the primer you get at walmart in the automotive section usually isn't worth a crap. you eithier have to use a self etching primer or you can use an epoxy based primer which has to be mixed and used from a spray gun. these are really the only two options for properly protecting bare metal. as far as bondo,that is a dirty word in my automotive colision repair class. it's autobody filler,and the bondo brand is worthless,use something from an automotive paint supplier, if you use inferior products you will get inferior results. there really is a big difference in the quality. my preference is for the nappa brand of filler,it actually csts less for the same size can as bondo does,and it doesn't have nearly the problems.

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Originally Posted by myaccord7

i dont know about that electric charge thing. rust comes from bare metal, water and oxygen. wet bare metal will not rust if there is no oxygen. ive never heard of electric charge causing rust.
zach

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you are right,rust is called oxidation,this is a chemical reaction,requiring iron,water and oxygen, seal off the water and you stop the rust,seal off the air the same. it takes all three parts. the reason cars rust so bad up north is that the salt attacks the paint and undercoating,then it reacts with the metal to oxidize it. salt is the worst thing that you could ever have for your car. if cars rusted from electric charges,they would turn to dust under the paint,and there would be no old cars. I think what they were refering to is galvanic corrosion,that is where two different metals,e.g. iron and aluminum cause an electric charge between then forming a battery in essence.

por-15 and navel jelly are ur friends to get rid of rust

hey lostdude. paint keeps out the water (electrolyte) which keeps away the ions and stops the oxidation, along with the net release of energy (electrical current created). however, give water a chance to eat at a bare edge of a painted piece of metal, and it will creep along under the paint. rustbubbles anyone?