Best way to wash off road salt?

[Bill in OKC]

I drove my car during a bout of bad weather (a long story) and got it all salty I know that a wash is mandatory but I have some questions. I did a search but my search skills must be lacking. Is there a product - soap or something that can wash/neutralize road salt? I know water from a regular car wash will get the visible stuff and maybe some of the salt underneath that I am lucky enough to hit but I would feel much better if I drenched it in something that might penetrate and maybe neutralize the salt. What about the big commercial car washes? Will they damage 23 year old Porsches? Thanks.

[azasadny]

Lots of warm water! Use your local "wash it yourself" car wash and remember to get the undercarriage and wheel wells washed off, too!

[GeorgeM]

Get on your knees and make sure you get it all off the bottom. I drove mine in Stuttgart with dry roads, but they must have had some leftover salt, and all the metal parts of my oil lines corroded... nasty stuff.

[crosby50]

At the very least, use a do it yourself commercial establishment. Just remember, the soaps they use are very strong and will likely strip the wax off your car.

[kach22i]

back in my early college days I did some janitorial work. There was this "neutralizer" we added to the mop water to eliminate the salt stains on the tile floors. I think you can get it at professional janitorial supply outlets, and I think it's designed not to strip the wax off the floor.

Please do a small test area first, I've never used it on a car let alone a Porsche.

[Zeke]

I would have thought a Google on the subject would have produced a number of hits. Not so. The idea is too neutralize the Ph, no? To that end, I'd think just a thorough washing would do the best job. But, you could use a diluted phosphoric acid as a rinse. This will convert forming rust to something more benign. I've read a few articles on this and I've seen anything from black oxide to zinc phosphate described as the resultant product. Whatever happens, it needs to be dried thoroughly and treated with a petroleum based preservative, AFAIC. There are probably alternatives.

[ChrisBennet]

Question 1: Do car washes recycle the water?
Question 2: Do they remove the salt from the recycled water or are you in effect "washing" your car with high pressure salty water?
-Chris

[EarlyPorsche]

Even if they do recycle the water they remove the "hard" aspect which would be the various calciums and salts. You are fine just using a commercial car wash.

[randywebb]

The idea is too neutralize the Ph, no?

No, I don't think so. [BTW, it is pH - the big H stands for hydrogen ion concentration, and the small p is for the log scale used.]

I think I'd want ot use lots and lots of water and if I could a soap soln. at first. So that means a comm. car wash.
Phosphoric acid sounds like a good idea as long as it doesn't damage anything else (paint).

Now -- HOW are you going to get it back from the car wash to your house w/o getting more salt on it?

Also, if it way cold in your location - you might want to just let the car sit. It will not rust if there is no liquid water. Your garage will be warmer than outside tho.

[Zeke]

Well, being a biochemist, I know you know what you're talking about. So, since there's not much info on this AFA Google, why not have a neutral pH (thanks for the correction, BTW)?? Which is better on the scale if not neutral? Or is that all there is to it (something tells me no)??

[Bill in OKC]

Thanks for the replies! The weather is nice today and for the next few days. I'm going to get a bunch of $1 bills (I know the perfect place to get lots of $1 bills) and just wash and squirt and spray until I run out of cash. I'll dress appropriately for laying down on a wet dirty public car wash so I can spray the undercarriage. When I was stationed near Stuttgart Germany, there were these great car washes where they raised the car on a lift and they would walk around all underneath and spray out all the little crevices with high pressure wands.

[peritus]

In the past, I have connected a household lawn sprinkler up to the hot water tap, and left it to soak every section of the underside, moving it around every few minutes for about half an hour.

[randywebb]

Biologist and Chemist but not biochemist....

Yes, there is more to it. It has been a looong time, but my guess is that we are talking about the scale of 'replacement' negatively charged ions.... O2--, Cl-, etc. and their affinity for metals, notably the iron in steel. Maybe someone who understands the process of rust chemistry better can comment. I DO know tho, that certain bacteria are implicated in rust processes. Somebody found this out a couple of decades ago -- ever since I heard about the study, I've treated rust like a disease -- complete eradication so it can't spread.

A neutral pH will be good however.

[Zeke]

Originally posted by randywebb
Biologist and Chemist but not biochemist....

Will I never get anything right??

Originally posted by randywebb

A neutral pH will be good however.

Oh, maybe I did.....

So, rust has bacteria or a bacterium? OK, I read some on the Net. Turns out that when you see a slippery red scum on the rusty area, the bacteria have combined iron and O2 to form this reddish substance that appears as a stain or a slime. Now, I've seen this, you've seen this, but it may not have anything to do with dry, rusty scale. Still, the water well folks who have to deal with this say chlorine will kill the bacteria. Maybe this is something we don't have to worry about spreading in the sense of a disease.

Again, I'm no where near a biologist or a chemist, but I seem to remember (that's chemistry, right?) that bacteria are pH sensitive for survival, be it a broad range or not.

I'm starting to like acid more and more if it's the right kind.

[Grady Clay]

There are some complicated issues at work here. Here is a simplistic version:

A salt in water is neither acid or base, it simply disassociates into charged ions when dissolved in water.. In high concentrations the ionic components of the salt are soluble in the water to various degrees. It is these differing solubilities and reactiveness that can cause the mixture to indicate slightly basic or acidic. In fact the mixture is relatively neutral pH.

When you add an acid or base to water, the same disassociation take place. The significant difference is half of the acid or base is an H+ or OH- ion, just parts of water. When you add an acid AND base to water (STAND BACK JACK), you get a salt and water (usually expolsively).

With a salt, pretty much nothing happens without water. However the water can even just be humidity. All rust is an electrical - chemical reaction that takes place in the presence of water.

The difficulty with an automobile is there are so many crevices and different materials all bolted together. If the parts are dissimilar metals, very bad things happens. Even a well protected metal surface (low corrosion alloy, galvanized, primed and painted) that has a totally unreactive plastic part will retain the water/salt mixture in the gap. Even the smallest piece of sand/dirt will, over time vibrate into (through) the protective coatings.

So, how to answer your question?

1) Avoid exposure to salt, water and dirt. Too late.
2) Once exposed, clean with mild soap and clean hot water.
3) Rinse with warm/hot water. Rinse some more. Rinse even more. If this were chemical apparatus the last rinses would be with de-ionized distilled water.
4) Get it dry and keep it dry. (Move to AZ, SoCal, Saudi Arabia.) It is very difficult to get the water and dissolved salts out of the crevices.
5) Periodically disassemble the parts, clean, reapply protective coatings and improve the sealing (or make it easier to rinse and dry.)

Depending on the model year, there are many things you can do that Porsche didn’t.

Best,
Grady

[Early_S_Man]

Bill,

After you have spent 30 minutes or so getting everything knocked off and then rinsed off ... I think the key is gegttting it dry ASAP! In the summer I would go for a nice one hour drive and feel very good ... but this time of year, I think the evening humidity build-up is going to work against your effort! Perhaps driving straight home and putting a couple of 20" box fans blowing into the wheelwells ... moved around a bit, front to rear every 30 minutes or so for a couple of hours would dry it out for you better that the drive in humid air? A final rest overnight in a dry, tight garage would be my prescription for best health ...

[Zeke]

OK, this is starting to get really interesting. Is there no "morning after pill?" What I mean if the salt has been rinsed, the car has been dried, it still rusts; any bare metal will. But, what stops this rust from occuring and reoccuring?

Now, I've done my own thing here by my own theory and method. After pressure washing and vacuuming with a graduated hose down to a 1/2 inch dia., I've shot phospho up into the body cavities followed by lots of compressed and heated air. (A good source of drier air than an air compressor is a shop vac using the blower.) I then blew POR15 into the cavities using a special set up that I devised to get it all the way up inside the windshield posts. After that dried/cured, I followed that with some body cavity wax and more air to drive it well into all seams not penetrated by the POR.

I did 2 early 911's this way. This was just in the concealed areas. You think that did the job?

[SP2]

I don't know about the phosphoric acid recommendation. Coke has phosphoric acid in it. Low concentrations, but you are not supposed to get it on your paint. My vote is for water. pH 7.0, or neutral. You wouldn't want to fire a 2 liter bottle of Coke all over your car.

[randywebb]

You think that did the job?

- probably, but you're (milt) in SoCal - very dry anyway

I'd use fans overnight - maybe over 2-3 days; maybe first I'd vac out any water I could see and try to vac out any crevice even if I couldn't see water...

[livi]

Vintage Porsche Passion!