hardwater stains

April 7, 2008 11:29 AM

I just bought a new car, and it was kept out on the lot. I live in Portland where it rains a lot. It seems to have hard water stains all over (they are like permanent little droplets). What are some good ways to get them off? Windex does nothing!!
posted by Infernarl to science & nature (15 comments total)

I'm always able to get hard water stains off by washing my car with soap. I use car wash soap and a nonabrasive scrubber. Then dry it off before the water dries.
posted by HotPatatta at 11:45 AM on April 7, 2008

How long ago did you by it? Since it is a new car, if I were in this situation, I would take it back to the dealer and have them clean it up. They can probably buff it out with something, and if you pay the premium for a new car, it should look *new*.
posted by internal at 11:46 AM on April 7, 2008

Zaino Z-12 Glass Polish. Avail in auto shops. Follow it up with some Rain-X, to keep the rain sluicing off.

P.S. Next time you buy a new car and they try to deliver it to you with water spots all over it, demand they take it out for a detailing before you accept delivery.
posted by jamaro at 11:50 AM on April 7, 2008

Wax on, wax off. Wax on, wax off. I liked Eagle-1 liquid wax before I bought a used pickup truck and stopped caring.
posted by hackwolf at 11:53 AM on April 7, 2008

If washing the car doesn't get it off, then follow up with detailing clay. It'll also remove environmental contaminants like rail dust. Leaves the car smooth and ready for wax/whatever. If clay doesn't get it, use a light car polish.
posted by pandanom at 12:31 PM on April 7, 2008

Rinse with a cloth and distilled water.
posted by Seamus at 12:36 PM on April 7, 2008

If they really are hard water stains then the buildup is calcium; either lemon juice or white vinegar + water will dissolve them.
posted by laconic titan at 12:43 PM on April 7, 2008

Since you don't say otherwise, I'm going to assume that the spots are all over the car, and not just the glass. DO NOT use Windex, lemon juice, vinegar, glass polish, etc. on the paint. They're great for use on glass, though.

A good wash, polish, and wax should get rid of the spots on the paint. Treat the car to a detailing. It'll never look better.
posted by Thorzdad at 12:56 PM on April 7, 2008

I am going through just this exact problem right and unfortunately don't have a real solution yet. I do know what people suggest, though:

1) 1:1 vinegar and water. Maybe I didn't scrub long enough with my microfiber towel, but this did not work for me.

2) Clay bar. Worked a little, but about only 40-50%. I only did my hood over about 30min, so again maybe I haven't put enough elbow grease into it.

3) Mineral spirits (paint thinner) and Goo-Gone. These are recommended for tar spots and the like. Did not seem to have any effect on hard water spots.

4) Straight waxing. I used Meguiar's NXT2.0 TechWax (or whatever it's called). This probably had the best effect.

As mentioned in one of the links above, it's possible that the hard water stains are etched into the clear coat and so will require extra work. This could involve either cutting into (polishing down) the clear coat or filling in the etches, both of which will require a tool.

Personally, I'm going to try some more claybar and hand-waxing before I buy the polisher, but hopefully the above can help you if only to get the dealership to give it a good going over by a qualified and skilled detailer.
posted by rhizome at 1:01 PM on April 7, 2008

A pro detailer I know swears by white vinegar and a Magic Eraser on glass and glass only, but YMMV.
posted by ScarletPumpernickel at 2:05 PM on April 7, 2008

A magic eraser is going to really make a mess of clearcoat. I would not try that.

Don't use a base like Windex. If anything, making the water more acid will help. Vinegar is a good bet.

Organic cleaners like mineral spirits and Goo-gone won't touch white spot of salts.
posted by bonehead at 2:42 PM on April 7, 2008

more info than you will ever need is at http://autopia.org/

and i say this with kindness, but these are the most anal people about car paint.

case 1: waxing the inside of tires
case 2: refusing to take ownership of a new car from dealer because it was washed by the dealer after specific instructions not to (to avoid swirls and orange peel)
posted by phritosan at 3:43 PM on April 7, 2008

Clay bar. Worked a little ... maybe I haven't put enough elbow grease into it.

Nth-ing the suggestions to just let the dealer sort this out (especially if they might ever want your business in the future), but just want to say this: you don't want to be using elbow grease with clay. All leaning on it and dragging it around will do is pick up contaminants from one spot and grind them across the rest.

The trick is to float it across the surface, folding as you go, with no downwards pressure, until you can't feel any grittiness / grabbing / stickyness. Using a lubricant instead of just water helps a lot.

(Not recommending Meguiars particularly, it's just the link that came to mind first...)
posted by Pinback at 4:42 PM on April 7, 2008

A clay bar or a mild cleaner wax should work. If that doesn't, you'll need to have it polished.

Personally, I would never let a dealer touch any car's paint. If you can, have them pay to have it clayed/polished.
posted by mphuie at 4:59 PM on April 7, 2008

I went through this a lot in Honolulu - could never dry the car after washing fast enough to prevent water spots. Auto parts stores sell mildly abrasive wax-like stuff for buffing out little scratches, etc. Get that, and a cheap orbital buffer. Make sure you get the mild abrasive and not the heavy stuff - they sell the same thing in different grades. Works very well for me.

Then wax it, to keep the water spots off in the meantime.
posted by ctmf at 5:10 PM on April 7, 2008