Us New Englanders have a serious rust issue - lots of trucks around here get COATED with roadsalt in the winter -mixed with rain and constantly shifting hot and cold temps creates the perfect recipe for frame and undercarriage rust.


But as far as rust goes how long does it take for surface rust to spread across the whole frame? How long until the integrity of the metal is Affected? 5 years? 10 years? In most cases is it reasonable to assume that mechanical issues will stop a rusted truck before the rust will?

what can rust do to a truck and how long does it typically take?

 

from 10-12 years worth




its hard to say. depends on how the veihical is maintained. How good the undercoating is, if your leaking oil all down the bottom side of the truck... etc

 

mine still has the original undercoating from under MOST of the truck...everywhere esle is surfice rust not a big problem...only other rust porblem is body...but it's still fixable...i belive the engine will need to be rebuilt before the rust kills the truck..

 

Environment is a big key - out here a little surface rust develops and that's it - doesn't seem to go any farther than that. (Unless you live on the coast...)

Back east and in the midwest it's not uncommon at all to see a vehicle so rusted out I would call it unsafe (and definitely uncool) to drive, but still runs fine. Rust is evil.

 

thats crazy...my truck definetly shows signs of rust, and I figure in 5 years or so it could definetly look like that. Its too bad cause I want to keep it forever

I try to wash the undercarriage at least once a week....but this damn road salt where I am in NH. My frame is literally WHITE half the time; it is painful to see the undercarriage coated with salt two days after you wash it.

 

Some people spray their frame with oil to help keep the rust away. Plus, you can always sand down the rusty areas as you see them and hit them with some rust inhibitor, or paint them up. It will help make the truck last longer. It isn't like having a little surface rust means you will never be able to stop your frame from rusting in half.

 

Heath whats the best grade of sandpaper to use for the frame?

most of the frame is ok..

But Behind my shock mounts is a disaster and there is quite a bit of deeper rust. I would say it would need more than sanding and is probably beyond what I am capable of.

 

My buddies 87 4Runner frame

 

i totaly can agree with the washing the undercarage then a day later seeing it white agian...i don't know how much longer the undercaoting can hold up tp that but the state should find other means of snow and ice problems than dumping salt everywhere

 

Holy Cow!!! I knew you guys had some rust issues up North, but that is just unbelievable.

 

I live in the same town as V RUNNER and here is one pic of my crossmember rust

note how the piece that should be suporting the rear of the tank is now gone in the middle. i had to sleve a pipe in and am currently holding the gas tank by a hose clamp

 

a good way to prevent rust is to use the "sacrifical anode" approach (see http://en.wikipedia.org/wiki/Sacrificial_anode - google for more info). the key is that rusting is oxidation which in chemical terms is a loss of electrons. the key is that if you put a metal that loses electrons easier than steel, that other metal will "rust first" what really happens is that the steel rusts (looses electrons) and then unrusts (steals electrons back from the other metal causing it to "rust"). this way if you just watch the sacrifical anode you can replace it when it's almost "rusted out". this is the primary way they prevent steel bridges from rusting out even when placed over salt water, or keep steel hulled boats from rusting, or prevent your water heater from rusting - the water heater usually starts to leak when the sacrifical anode is gone. what you want to do is place an easily oxidized metal (magnesium is the most common, i think aluminum will work too) between the metal that you don't want to rust and ground. it should protect anymetal that it's in electrical contact with. i'm not an ee, but here's what i suggest: just wire one side of the metal to the frame and the other side to the negative battery terminal. i've never done this since i live in the land of no rust, but as a chemist it makes sence to me and if i lived out east i'd do it.

 

The Same premise applies for your hot water tanks (I'm a plumber). All hot water tanks have a sacrificial anode in them made out of magnesium. This gives off electrons easier than the tank walls so it rusts first before rusting out your tank walls and bursting your hot water tank. This one I hate to say is a little bit of a scam though. Usually hot water tank manufacturers warranty their tanks based on the projected life of the sacrificial anode. They'll put a higher quality/longer lasting one in the longer warranty hot water tanks. If you buy a short warranty tank and just change the anode to a better one you can improve it's lifespan. They also make these anodes difficult to remove, to the point where you almost need a special tool to get at them so people will end up changing their tank completely instead of changing the anode. Hot water is much more corrosive than cold water generally speaking as a note.

Having said that if I lived in an area where I saw more salt/potential rust issues I would spend the money and have the body taken off the frame and paint the entire frame with POR-15 paint. Yeah it'd be a bit pricey for the paint to do this job, and a bit time consuming and labour intensive, but I think it's easier than getting involved with chemistry the way I see it!

 

you know when we start talking about sacrificial anodes to keep our trucks from rusting we are screwed.

 

The electronic rust buster and the sacrificial anode will do precisely nothing to help your truck survive the salt rust. Salt corrosion is not the same as electrolyses or galvanic corrosion. Salt in the presence of air and moisture Chemically eats into ferrous metals at the point of contact.

 

I suppose what grit of sand paper depends on how bad the rust is...start with a wire brush, get it down, then sand it to steel. You could use a grinder too. The main idea is to remove the rust, treat what is left, then cover the remaining area to keep it from rusting. There is no way to completely prevent rust here in NE other than never drive the vehicle.

 

absolutely! but nevertheless, i am trying to decide between por15'ing my whole underside, frame, axles, etc. or having it professionally undercoated. any opinions on the merits of either are most welcome.

 

Can you say "anode" in this forum???

 

POR-15 the entire underside and your frame and you should be good to go.

 

IMHO...there are better/more environmentally safe methods of curing icey roads. Salt not only eats away at the metals on vehicles when spread on the roads. It also eats away at the surfaces of the roads you are driving on. Asphalt...concrete, doesn't matter. The damage is NEVER ENDING as you see from what it does to your vehicles. I'm surprised that they use salts considering there are liquid types of ice killers that is used commercially here where I live. The liquid stays on the surface it's put on for a long time too.
Only thing I can figure as to their way of madness, is that there's salt readily available, and the street/highway department doesn't care.