This isn't really a detailing question nor a service question... I don't think. But here it is anyways! I HATE rust! I need my car to last since the economic blah blah blah has pretty much killed my business. So my question is do you and if so what do you use to spray the underside of the car to prevent rust? I have been told cosmoline, wd40, trans fluid and trans fluid mixed with wd40. If you have done this what did you use and how messy is it? Did it work? I know there is a rust warranty but BMW's version of rust (perforation) and mine (smallest bubble) are very different! so help me out fellow members! I would like to know what you use and how it works out! Thanks Damien PS the bottom two answers in the poll are just fun. If you do vote could you explain your vote a bit? Thanks!
Damien, Years ago, oil spray was a popular way to stave off the iron-worms. That was before zinc-coated steel panels and the much better external finishes of today. The only problem that motor oil or tranny fluid caused was the grit and salt and dirt that adhered to it. With the superb bushings and brake rotors and wiring on today's cars (generally), I wouldn't apply an oil underbody coating. Don
Griot's Undercarriage Spray is just a detailing tool to hide dirt and discoloration on black parts and enhance chassis details, NOT protect anything. I saw an episode of Dream Car Garage (from Canada) where they sent a car to Krown to be spray coated underneath and in wheelwells for winter salt protection. Apparently it did a good job, then was cleaned/removed in the spring http://www.krown.com/#default
is it worse than oil ? at least it coats to a degree. and isn't so permanent. i posted the link so as to ID what it actually is, not to mislead. give me a break.
Anti rust There is only one way to keep rust from forming. its to make cars from a product that does not rust. other than that you have to keep your car as dry as possible. Get an old clunker to drive in the bad weather..Move to a dry climate. Wash your car only when necessary.Go to http://www.wetpaintglaze.com/. No washing... Bluewagon
I'm seeing a runaway leader here ... If kept reasonably clean, no BMW under a dozen years old will have any serious rust problems. Heck, even among E28s (the last of which was built in 1987), there are very few structural rust problems. BMW got on the bandwagon around the same time as Audi did in the middle and late '80s and started making really really good bodies that take decades to rust at all and even longer for it to be anything other than a purely cosmetic problem. If you are planning for this car to be yours for over 25 years, you might want to look into extraordinary measures like this. Otherwise, I wouldn't bother.
Mike Miller did an article on prepping a BMW for winter I can't remember if it was in Bimmer magazine or Roundel but anyway he gave out a formula of things he mixed together to make up an underbody spray to protect against rust. I'm sure you could email him and get the formula he uses. Unlike south Texas, where I live, he lives in an area of the county that has real live winters with snow, ice and salt - the man knows his stuff....
Reality check time, again I just had to have some brake lines replaced (from master cylinder to rear wheels) on my 1992 Lexus LS400 due to perforation of the lines from MI winter salt exposure. Cost me just under $500 at a local Midas shop. Cost was 1/2 labor and 1/2 parts. Lots of labor because the lines were behind panels that were tough to get off. Work was done at an extremely reputable and honest shop. In talking with the owner/manager of the shop, who I consider a friend after decades of dealings, I said that I wished that Lexus had used stainless brake lines so that they would have lasted longer than 18 years in MI winters. He noted that he bought his wife a BMW X5 some years back. She companined that the X5, at 5 years of age, had a spongy brake pedal. He thought it just needed bleeding. Reality was that a brake line had already rusted through and had to be replaced. That's at 5 years of age. Made me feel better (a little ) about the LS400. - GRL
A continuation of the LS400 story. We kept the 92 LS400 until 2014 using it as a winter car (with snow tires) in mid-Michigan where a lot of salt is used. (It was a GREAT car, by the way, and only sold it because we do not need or want 4 cars.) As I was selling it, a buyer wanted it inspected at a local shop first. The shop discovered leaking brake-lines. The leaks were small, but they were there. naturally they had to be fixed. This time the cost was about $1,000 and the reason was not the all-new parts (custom fabricated tubing sections), but the labor due to all the shields that Lexus had over the tubing. The shield fittings were, of course, rusty and hard to get off. Lots of labor. My walkaway lesson from this that if you live where salt is used in winter and want to avoid underbody rust you MUST apply a good rust-proofing. Where I live there used to be a Ziebart shop and there still is a Henderson Brothers Rustproofing shop. Ziebart used a hardening/hard wax rustproofing spray that, in fact, caused underbody rust when the hard wax cracked, trapped salt spray, and then was sealed over at the "annual inspection" by a re-spray of their "stuff". I had massive holes in the C-section frame rails of my F150 pickup because of that. The Henderson Brothers use a non-drying very thick (very viscous) tar-like oil than never dries out, always stays tacky and will flow over areas where you get a rock impact, for example. As I said, Ziebart is (deservedly) gone and Henderson Brothers is still here. I ALWAYS go to Henderson with every car I buy new or used that will be driven in winter. Their stuff has a strong petroleum odor when first applies and sometimes you get a few drips until the solvent evaporates, but it works! I also go back every 5 or so years for a touch-up re-spray. Bottom line is that if you don't want underbody rust on a car/truck driven in salty winter conditions you need to either have someone apply a viscous tar-like rust-proofing compound or do it yourself. - GRL
I was one of the "what's that". I now live in the Pacific NW and work from home. It only snows a couple of times a year and they only have 2 or 3 plows in the area. I can stay in on those few days and wait for it to melt. I used to live in the NE and know with salt and rust are. I feel your pain.
