Expert: Robert Lamb - 8/19/2011

Question
i work for a carwash.the glass is stained white with build up. not sure if it calcium or what. the owner got some acid like u would use on aluminium wheels, and also tried another type of chemical. tried them both diluted and strait. it didnt have much effect either way. what other options do i have other than replacing the windows. the windows are 3ft by 8ft.and there are about 21 windows at one and the other has about 18.

Answer
Ron,

There are basically two things you can do if your glass has what sounds like "hard water spots". The first option is to use mechanical action, basically buffing out the built up mineral deposits. The second is to use chemical action, let the chemical remove a fine layer of glass to reveal a new, smooth layer.

We have had a lot of success removing hard water spots using a product called Crystal Clear 550. The product is an acid based formula that includes hydrofluoric acid. The product must first be tested in an out of the way area. If it is going to work, it will work like magic. It's as simple as wiping it on and wiping it off. In rare cases it will cause an acid burn that will make the glass have a tin haze or greyish spot. Without getting too technical, tin haze has to do with the way float glass is made. The important thing when using this product is to test it as mentioned above and closely follow the safety directions on the bottle. After glass restoration with this chemicla processes, the glass needs to be cleaned using standard proceedures.

If you opt for the mechanical method of removal, that too includes the use of compounds (chemical compounds) that will remove a fine layer of glass revealing a polished, smooth glass. Zud is a cleaning product that may work, but it is at the very low end of the scale as far as effectiveness is concerned. It is also very labor intensive. If you decide to use the mechanical method of stain removal, there are other products that would probably give you much better results.

Actually you can find all the supplies mentioned above online at a window cleaning supply house like ABC Window Cleaning Supply or J. Racenstein, as well as others.

Here's the chemical method link to one supply house: http://tinyurl.com/2br7hcy

Here's a link for tools you will need if you choose the mechanical removal option: http://tinyurl.com/38kbx7s. Again, if you go this route, you will also need some of the chemicals in the link above.

Of course, if you don't want to tackle this project yourself, you should look for a window cleaning company that specializes in glass restoration. If you need one, give me a shout as I know literally hundreds of window cleaners.

One other thing I should say is you should really put some sort of protective coating on your glass once you have restored it. A low tech product would be something like Rain-X and a high tech product would be something that uses nanotechnology. I can help you with that too.

Please let me know how things turn out.

Sincerely,

Robert Lamb
Window Masters
http://www.window-masters.com