Winter salt cleanup and corrosion prevention (on parts that aren`t shiny) electricity experiments


I`m currently driving the newest/lowest mileage car I`ve had yet. It`s a 2011 so it`s not new anymore, but I`m looking to even further step up my game to do my part to make it last. One thing I`m unsure about is how best to do undercarriage, under hood, nook and cranny salt removal and corrosion protection. I`d like some suggestions and discussion. I`ll state right off that I simply don`t have "Accumulator" kind of time, to get under a vehicle and clean with woolies every time I wash. I wish, but it just isn`t happening (or he`s been joking all along).

The vehicle is a 2011 BMW F10 535xi (that only has about 35k of daily, all season miles at this point). It is constructed of double galvanized, seam-sealed steel, lots of aluminum and some composite. Many fasteners are aluminum too. The underside has lots of covers and panels and looks something like this (not exactly my car, not my photo):

• In the spring when I need to clean up, tap water is just above freezing – I don`t think it will be effective at dissolving away salt in any significant quantity. I don`t have ready access to warm/hot water to run through my pressure washer but I might be able to rig something up with a garden hose running through the hose.

So, is there a combination of cleaners (safe for the construction) that would help get a grip on salt even with COLD water? I have 1Z W99 (has aluminum warnings, but can`t remember if they still apply when diluted), 1Z Blitz, Simple Green, lots of car shampoos, D143, and a whack of other household stuff. Is something like Bio-Kleen Salt Kleen actually any good?

Is there a REALLY nice product from Wurth or similar that could creep, protect, and set up NON-STICKY while providing a fairly thin film that won`t get all bulky and hold salt? I wonder if I should just be using something similar to, but more advanced than, Cosmoline after a really thorough clean up.

The detail shop, where I learned the basics AND how to properly rust-proof a car, will often use a Murphy`s Oil Soap mixture to help dissolve the salt & rinse it away – without disturbing the already-applied undercoating (thick and gooey) between annual touch ups of the undercoating product … Murphy`s is NOT good for a waxed surface though (it cleans pads out well though), but the oils in the soap that are good for wood, seem to neutralize and draw out the crusted salt.

This is also a good use for a foam gun/foam cannon. Using a heavy concentration of soap in the mix, thoroughly saturate the undercarriage with soap/foam and LET IT SOAK! Since you`re not going to be doing any physical scrubbing, you are relying totally on the cleaning power of the soap, so letting it soak is going to be the best way to do it, maybe even multiple applications and rinses – depending on how bad the accumulation is.

I`ve noticed that the majority of rust on the undercarriage starts within the first 1/4 to 1/3 of the sides of the car (the areas that get road splash from the tires) … the center section, not so much, so by concentrating your cleaning efforts to the first foot, 1-1/2 in from the rocker panels, and mainly thoroughly rinsing the center section of the under-body, should be your primary goals. Using this theory, manual scrubbing of the rockers and the immediately surrounding under-body with a long handled/soft bristled body brush is quick and simple.

When you get it cleaned you wrote about würth products. So did a little google for you I don`t know how your cars are delivered in the US. But here in Sweden they are rust protected with a thick and dry to the touch undercarige protection. Thrue the years if not maintained they dry and cracks up. So you have to apply a new layer of the undercarige products. This würth product seems to be the same kind of products used to do this. It`s stops the corrosion that have started. Then you have a thinner product of this kind that you spray in doors and other places you don`t get to brush or spray it on. It`s a mist it in the places and for an example the chanels that the water runs through in the cars body.

The salt is water soluble but it desolves many of the dirt that is left on the roads and then bonds with it to the car. Undercarige products is almost like tar and that is the problem when you are going to clean the it. Since the cleaners that are most effective to get the salt cruds and road grime off also desolves the undercarige products that are used. So when cleaning I use a alkaline based degreaser and a brush that the PW don`t get. And if I see any dried up rust protected product I use a stiffer brush and then apply it with a brush. If doing larger area it`s easier to spray it on but man is it a dirty work to do.But worth it if you are planning to keep the car for a long time.

As I mentioned – when using a touchless wash during the winter, I always opt for the undercarriage option. I`m just not really sure whether the salt removal of the carwash can compete with 2 hours at 65mph through brine when it comes to creeping into seams and under covers.

Marine products for salt removal are an interesting spin for sure. But, there`s no salt water even remotely near me. If I were to shop in marine circles, I don`t think there would be any products or expertise in salt water issues. So, I`m back to ordering online. Thus, I need to know what I want before I order it. Hence asking real humans. Asking google doesn`t always get you the right product.

SWETM: As you mention – salt is water soluble but like I mentioned the ice cold tap water in the spring when I need to get this done doesn`t seem to have the power on its own to clean salt off. I`m even less excited about lying on the driveway under the car in ice cold tap water, spraying ice cold tap water at the underside of the car inches from my face. Sigh.

Yes I do have a foam gun, but not a foam cannon at my disposal. I do have a gas powered power washer at my disposal, but it`s not something I`ve ever used for cleaning up the car. It`s never been needed on the shiny bits or under the hood and frankly it`s a PITA to deal with. The question would be – with either foam gun/cannon – what product do I spray out of all of those options which will foam, attack salt and grime, but not react with any of the materials in the construction of the car, or cause problems at dissimilar metal interfaces? Oh, and I can order online to Canada?