Best way to prevent rust?

[qwerty333]

I have a w123 1983 300d...

It was originally from florida...and I believe the original owner had fixed some body rust and repainted the car (with a cheap maaco paint job...overspray on literally all the trim), then sold it to somebody in canada. That person owned it for 2 years and I bought it in April of 2017.

Right now the car still has almost zero visible rust, except for some reforming rust on the right side of the trunk cover and some light spotting under the left headlight. Thee are only visible if you look closely. The fenders and other usual rust spots are perfect.

Right now I'm driving it during the winter in canada, and washing it whenever possible (every 2-3 days whenever its not too cold) just to clean off the salt

the previous owner in Canada had it undercoated/oil sprayed at Krown, and I've continued the tradition

Is there anything else I can do to prevent or monitor any rust that is developing and stop it in its tracks? I'd like to keep the car rust-free for as long as possible

[Ferdman]

qwerty333, what you are doing seems like the best approach to ward off rust issues. It's likely there are spots where rust was removed, coated and painted over that may reappear over time, but there is no way to address those unless you want to strip the body to bare metal and start over.

[qwerty333]

Originally Posted by Ferdman

qwerty333, what you are doing seems like the best approach to ward off rust issues. It's likely there are spots where rust was removed, coated and painted over that may reappear over time, but there is no way to address those unless you want to strip the body to bare metal and start over.

If I get a rock chip and it has salt sit on it for a few days will that start rust?

[Ferdman]

qwerty333, theoretically rust will start on a microscopic level where salt brine remains on a stone chip spot for a few days. Washing the salt brine off and applying a fresh coat of wax over the stone chip spot would best alleviate any rust issue. The areas where rust will likely reappear are those where past rust was supposedly completely removed, then coated/painted over. Because it's likely there is a pinhole(s) where salt brine can penetrate the refinished surface and form rust that is hidden and goes untreated until it becomes a major issue and is clearly visible, or a bit of hidden remaining rust spreads and goes unnoticed until it is a major issue again. Rust is like cancer, in that it is difficult to eliminate completely.

[CTD]

The best way you can avoid rust is to not drive on salted roads when they are wet. The best way to do that is to operate a second "snow" car reserved for bad weather.

If you are unable to do that, then the second-best way to avoid rust is to wash the salt off quickly after every exposure, and do a thorough inspection, cleaning, and touch-up of the vehicle's undercoating every spring.

Another thing you can do is keep a broom/brush in the car, and brush any snow off of the fender wells, rocker panels, and rear quarters after every drive. It usually takes about a minute or two, but it allows the undercarriage to dry faster and prevent brine-related corrosion. I do that with my vehicles when operating them in the winter season.

[Sugar Bear]

Sounds as though you are already doing a very good job, a couple of thoughts...

If you can rinse with hot water (not always feasible but..) it dissolves contaminants better than cold water and it evaporates/dries faster,

Cold storage reduces condensation, it can be better depending upon temps to leave the car outside,

Washing under the fender well lips with a wash mit dedicated to those areas only helps a lot,

A lawn sprinkler can be placed under the car, left in one spot for a couple of minutes and then relocated,

Driving a long distance in a heavy spring rain helps wash away the salt,

Keep the drains for the sunroof and the hood spring pockets clean, and

Use the vent on the side of the battery buy connecting a piece of tubing to it and venting it down and out under the car away from sparks and heat sources. This vent not done properly causes a lot of rust, take a look under the hood on any 123 chassis and notice the rust under the hood above the battery and the rotted battery tray leading to a rotted firewall.

Good luck!!!