Dealing with hard water stains on your windows can be tough.   The good news is that there are a couple products at your local home improvement store that will help take the stain out. The secret to removing the stain completely is to use a 4-6 inch hand held stainless steel razor that is meant for removing paint or construction debris from glass. If the stain has been on the glass for a while and you just spray or wipe on the calcium, lime and rust remover many times that will not remove the stain completely.

Here are some quick tips on removing hard water stains completely:

  •  Zep brand Calcium, Lime & Rust Remover at Lowe’s or Home Depot works the best
  •  Apply the solution to the glass using a spray bottle or old towel (wearing gloves is recommended)
  •  Wait 5-10 minutes for the solution to react with the stain
  •  Use the razor to lift the hard water deposits while the stain remover is still on the glass
  •  Mix dish soap with water in a bucket
  •  Use a towel with soap and water to wash the glass
  •  Squeegee off remaining soap and water
  •  Use a lint free micro fiber towel to dry the window edges

There are a few alternative ways to remove hard water stains as well. I’ve found the one mentioned above works to remove the stain about 80% of the time. Completely eliminating the original stain that was sometimes built up for over 10 years. If the stain doesn’t lift with this method you could try calling a local glass restoration company. They will have special glass buffing equipment that may be able to remove the stain. Or another possibility is to replace the pane of glass where the stain is.  Sometimes this method could cost about the same as glass restoration so be sure to compare the two.

Keep in mind all glass surfaces are different. Some glass scratches very easy and some doesn’t scratch at all.  It’s important the razor blade you use is stainless steel. Some people use a cheap one inch razor that is subject to instant rust when it gets wet.  Most of the scratches we see on window glass is because the person used a cheap razor for the last cleaning and wasn’t familiar with the type of glass it was.

If you hear a sharp screeching sound like dragging your keys across glass it’s probably a good idea to stop using the razor. This sound usually indicates the glass is gonna be scratched after making a few passes with the razor. Depending on how raised the stain is may require a different amount of pressure being applied to the glass with the razor to take it off completely.

If you decide you don’t want to take on this project yourself, hiring a professional window cleaner may be the answer. Just mention to the window cleaner when they look at your property that you have a few windows that you would like the stains removed from. They can include that in your estimate and it could probably get it done this week.