Do any of you have lime deposits (the water spots that won't go away with windex or washing) on your windows? I do, and they're especially prevalent on the rear 5 windows. I've tried several things, all to no avail. Am I alone here or has anyone fought this battle before?

Zach

 

I had this same problem; we have very hard water here. Just dillute some vinegar with water and apply it with a paper towel. then dry it with another paper towel and go back over it with windex. It works great for me.

 

You might try mixing some washing soda or borax into your wash bucket before you wash your rig. Let the bucket stand for 30 min or so...especially if it's cold. The Ca++ ions should be precipitated out of the water and replaced with Na+ ions ending your problem with lime buildup.

 

Try using some CLR Calcium, Lime, Rust remover. You can buy it in the household chemical aisle, at just about any grocery store.

 

yes. CLR and fine steel wool. Steel wool does not scratch glass if thats what your thinkin.

 

Well the Ca (+2) is binding with something, and that's what is precipitating out, not just the ions right? What's the rxn for this? Is it ppting out CaCO3? Just curious, its been a long time...

 

soap is usally some type of acetate with a longo hydrocarbon chain that makes it have a dual polarity so it can cling onto the dirt and the water. Usually of some form -COOH.

 

I use RainX on those... Usually takes them right off. Sometimes you have to apply it twice, but it gets most anything off. Makes water fly off the window for the next two weeks as well.

-Byron

 

Tom...
In the case of Borax (Sodium Tetraborate, Na2B4O7) you would precipitate out CaB4O7 or Calcium tetraborate. What would remain in solution would be Sodium Carbonate or Sodium Sulfate, depending on your water's chemistry. It should be safe to use on Aluminum also, but test it first.

Washing soda is Sodium Carbonate. Upon reviewing it, skip the washing soda. While it would appear to soften the water, it doesn't, it merely makes the water more basic. This would make the water "feel slippery" but not actually take the Ca2+ ions out of solution. It would probably harm your aluminum.

 

This thread has gotten way too technical and is bringing back some not-so-pleasant memories.....

 

I spray windex and then scrape it with a razor inside a razor holder. The windex helps lubricate and break down the build up. No scratches and quickly removes the junk.

 

Come towards the light John....
You will feel warm and happy....

Now repeat after me...
Chemistry is fun,
Chemistry is fun.

 

Ya no kidding. I thought I had escaped freshman year chemistry two years ago, only to find that it was now infiltrating Yotatech....ahhhhhhh!!

 

OK cool, I guess Borax isn't made up of exactly what I thought it was! Time to dust off the ol' general chem book I guess.

 

use some of that Kaboom. it must work, Billy Mayes says so

 

Acetic acid should do the trick- most metal salts precipitate out of water (forming metal hydroxides at high pH), acidic solutions will re-solubilize them. Just remember, if you're not part of the solution, you're part of the precipitate!

Chemist

 

First of all, thanks to everyone for the advice. I might try the vinegar, or maybe I'll ask my chemistry teacher (I'm in high school), if she knows what would take it off. The formula for lime is definately CaCO3 (calcium carbonate) then, right? Now I know you all won't believe this, but I actually like chemistry. I'm definately a math/science person, and I'm taking honors chemistry 1 as a junior. I plan to continue next year with A.P. chemistry, so wish me luck! And then I had a question for Mad Chemist: are you really a mad chemist?


Zach

 

Zach...
"Lime" is usually, but not necessarily always CaCO3. It's used pretty indiscriminately to describe any water deposits, whether they be carbonates, sulfates or any other ionic compounds. Whether your deposits are actually CaCO3 depends on the chemistry of your water supply. CaCO3 usually is found in surface & groundwaters that flow over/through limestone formations or unconsolidated limestone sediments. However, you'll also find a lot of sulfates & sulfides in those same waters.

Mild acids, of course will probably take the water spots off, just try to limit exposure of the acids to the paint, aluminum, iron, etc. Work the reations out yourself...you know the possible reactants....figure out the products. The reactions are usually double replacement. Then take it into your teacher for perusal.

 

I got my B.S. in Chemistry, and my Ph.D. in Biochemistry- so I guess I should have called my self "Mad Biochemist!"

 

It sounds like gwhayduke has some training in the sciences himself