Question for the car experts

[Hawaii Hiker]

I have a 1998 Nissan Altima in, for the most part, excellent condition...However, there is some rust forming in underneath areas....Someone at work told me to go to Pepboys buy a spray that helps slow the rust process down..He also said to buy an undercoat, & spray that on a day after...

Now, can this stop the rust, or does it only slow it down?....I was always under the assumption that rust can't be stopped once it begins...

Thanks

[krispos42]

1. I think rust is too porous to paint

Moisture still gets in there to chemically react with the steel and make more rust.


You have to sand/wirewheel the rust off first, then prime and paint it.



You can buy this undercoating that's like tar in a spray can that can go on there as well. It's ugly, but if it's underneath the car then who cares, right?

[Hawaii Hiker]

2. Exactly, if it's underneath the car,

it can look ugly...That's the way my friend described it, he said after you spray the undercoating, it will turn the rust black...Other than those few rust areas underneath, my Nissan is in really good shape, w/low miles to...

[SacredCow]

3. It slows it down pretty well.

A good rust converter and encapsulator can buy you a lot of time, but eventually the rust will come back.

I'm using Eastwoods converter on my Beetle until I get around to fixing the rust spots properly.

[madrchsod]

4. you need a product like this

http://www.theruststore.com/Rust-Converters-C10.aspx

then use a good rubberized undercoating. use a mask and full coverage eye wear. i`ve spent years battling rust here in northern il and rust converters and rubberized undercoating last the longest

[Mopar151]

5. The converter is key!

turns the rust from iron oxide into iron phosphate.

The fish oil in original Rust-Oleum is pretty damm good, too, when you do enough surface prep.

And then there is OIL UNDERCOATING - nasty, messy, should be done every year, leaves a poultice of oil and dirt 1/2" thick all over the bottom of the car. Usually found in rural areas of northern states. I've seen 30 y/o cars oiled with virtually no rust, and every bolt and adjustment under the car is free.

[madrchsod]

6. a guy i worked with drove his car through several miles hot tar...

the underside of his car was dripping hot tar....one of the funniest things i`ve ever seen...

ya that free hot oil treatment worked wonders ...esp to the paint.

[NecklyTyler]

7. Put Ospho on the rust before you paint it

Ospho is phosphoric acid (beware - buy this stuff and you are on your own) that causes a chemical reaction to iron oxide and stops metal from rusting. It will also discolor aluminum, paint, some plastics, and your skin. Just kidding about the skin, but you really don't want to get Ospho on you.

[bluedigger]

8. How long do you want to keep the car?

It's a 98 Altima, after all. A good car, but about to be 12 years old, and not going on any "collectible" lists any time soon. Surface rust is inevetible and expectable on a car that old. If it is just "ugly" and doesn't lead to any safety issues, I'd just live with it for a few years. If you have access to a lift and just like messing around with cars, then attack the rust and have fun, but I wouldn't lose any sleep over it, myself. I'd put the money for rust treatment into the "next car" fund.