Steel Wool?
Brillo pads?

 

There are many specially formulated water spot removers from the major brands, Meguiar's, Mother's, TurtleWax, et cetera. There are also specialty detailing brands. Every single one of them requires A LOT of rubbing to work. Go on Amazon and read the product reviews.

Don't do anything stupid that would scratch or mar your windshield.

 

I've used Bartenders Helper in the past with no mishaps. YMMV.

 

Is this a hard water problem? I can't think of anything else that wouldn't just rinse off.

 

Vinegar is an acid with a low pH. If that did not work, try something basic with a high pH. A weak sodium hydroxide (lye) solution might work. Sodium hypochlorite (bleach) which has a pH of about 11 might work.

 

Water spots

Actually, I just read a Good Housekeeping email this morning that had a whole list of little known uses for WD-40. Auto windshield water spots were on the list. I haven't tried it though.

 

I successfully removed some wiper blade scratches from my windshield where PO had driven the spyder on the beach. Sand scrubbed some bad arcs in the glass. It was a rubber pad with cesium polishing compound - I think Eastwood sells the kit. A lot of hard work with an angle motor drill. I also tried removing some “hard water spots” from windows on my garage from a wayward sprinkler. That was a total bust - didn’t seem to even phase the spots so they remain.

 

tried the WD40

The WD40 was right there so I tried it tonight. It made difference. But it got dark and couldn't tell if it is all gone. I will check it out again tomorrow.

Never know what you can do with WD40. Not ready to try it as a hemorrhoids cure yet.

 

I've always had really good luck with barkeepers friend. I pour some into a bowl with water and form into a paste and kind of "buffi" it into the glass with my hands and then using a microfiber towel to wipe it off the opposite direction. Has worked great on windshield and glass mirrors on many of my cars and bikes. I think there is now branded products out there to do this.

 

Aren't water spots just Lime or Calcium? Can't you (very carefully) use CLR or LimeAway on your windshield? I would just be careful to not get it on the painted or aluminum surfaces.

 

Most hard water spots are usually calcium or magnesium. Although, many water systems are different, most of these deposits are alkali in nature. So an acid based cleaner should in theory remove them. There are also silicate deposits and in some cases there are other deposits that are acidic in nature, most come from acid rain, but some can come from water in our tap. For those type of stains a basic solution might be needed or a very strong acid. Some acid or base water deposits can eventually etch glass so you want to take care of them quickly. Eventually, what looks like a stain is actually etching damage to the glass, and in that case, buffing is usually the last resort.

 

goo be gone...

 

A clay bar worked well for me.

 

yes. try claying your windshield. actually, try claying all your windows; inside and out (mirrors too). you can then use Klasse AIO as a finishing step also.

 

I've used a product called windshield stripper. It's a mild abrasive to get RainX build up off your windshield. It has also removed water spotting for me. You just put it on a clean cloth and buff it on, then rinse off with water.

 

Try CLR

 

Griots has a product for getting rid of water spots on windshields. I have not tried it, but just saw it listed in a catalog I received from them recently.