Undercoating a daily driver?

[Hoopty_Mike]

My daily driver is my 87' cutlass. It's pretty much rust free, and I would like to keep it that way as much as possible. I take it to the DIY carwashes and try to get everything off. Once spring rolls around I jack the whole thing it and hit it with the power washer.

I was thinking about some form of undercoating. It had ziebart or something like it sprayed from the dealer. Like any 25 year old car it has surface rust, so I was thinking of staying away from paints/traditional undercoatings. I have heard of things like spraying the underside with motor oil or even chainsaw bar oil. I'm open to all suggestions/advice. Thanks.

 

[Bonnewagon]

Ever notice how a car with a rear seal hemorrhaging oil all over the bottom never has rust there? Not practical though. When I fixed all the rust on the Bonnewagon I used POR-15 on everything, then a thick coating of traditional undercoating. So far so good and this is a working wagon. Then, back in '89 my Mom bought a new Cutlass Calais and I noticed that there was no undercoating. The powers that be claimed no need for it with modern metals etc, yeah right. So I bought a case of large cans of undercoating, dropped the exhaust system, and used all 12 cans on the undersides. 25 years later, solid floors, no rust, so I am a believer.

 

[L.A.X-RATED]

^^^^^x3 on the "process" :wink: yeah this is the same steps/process i use on the underside of my g's(even though they are trailer queens,and in the "rust free" zone.)im currently going to be doing this to my sons 90 xj should suffice and hold up to the trail riding and occasional "snow playing" at our ranch in newmexico 8)

 

[Hoopty_Mike]

Any brand/type of undercoating that you prefer? I had contemplated doing my frame rails and whatever else I could get to with POR 15. Looks like a can of that will be on the xmas list.

 

[online170]

Carwashes and underbody wash is key to preventing rust. Salt and Dirt are what cause rust, so if you keep it clean, you will fight the rust.


The city where I live LOVES to use salt. Even when theres no snow or ice. Its like they buy a bunch, and have to finish it before the season is out. I get my car sprayed by a rust proofing company. They get all the hard to reach spots so it works well. I also keep a can of it in the car, and spray where I see salt coming into the interior after a carwash. I use Krown, and Rustcheck. I think the when and how often you undercoat is more important than what you use.


Its a tough fight, but it seems to be working. The rust on the daily drivers I have hasn't gotten any worse on any vehicle I have owned.

 

[565bbchevy]

I myself prefer the 3M rubberized undercoating it seems to hold up the best on my daily driver.
But if there is any kind of rust present I would first apply POR 15 on the bare/rusty metal.

 

[online170]

One more thing, invest in a good set of mudflaps. They less crap you spray on the underbody and rockers with your tires, the easier it will be to maintain.

 

[northern]

Just got my 87 442 undercoated myself, I stay away from the rubbertype coating as it seems to dry out and trap moist, oilbased stuff seems to work best on old cars with surface rust. After reading alot of reviews I went with fluid-film. That, along with regular washing and mudflaps work wonders

 

[joesregalproject]

My car had a good bit of surface rust underneath, and it is unwise to put rubber undercoating on top of surface rust. So I decided to use 30 weight oil. It is a little messy (and VERY old-school) but the nice thing about it is, it is removable and over a period of time will actually dissolve rust. I coat it once a year.

 

[Clone TIE Pilot]

Best thing is to avoid exposure to salt altogether. Even the best coatings only last so many hours against it.