Outdoor Tabletop Stain Removal

The Case of the Ghostly Glass Gunk

Question:

Dear Glass Detective,

I have an outdoor circular glass table about 27″ in diameter. The glass on both sides is what I would call “wavy”, not just clear. It appears as if many coral atolls are side by side. (visualization). You can feel the uneven contours. On the glass it appears as if round objects – like planters have been left a long time. You can see the ghosts of the rings they left and I have not be able to remove some. Can you help?

Thanks,
Steve W.
Gettysburg, PA

Answer:

Dear Steve,

Let me begin by thanking you for contacting the Glass Detective with your question about how to clean an outdoor glass tabletop that has (what you have referred to as) “ghosts of rings” on the surface of the glass, possibly from planter pots or vases.

Your good description of the glass itself leads me to conclude that the glass type you are referring to is what is commonly called “smooth rough” or “surf” patterned glass. There are other names for this glass pattern, depending on who the manufacturer might be, but I do believe I know the glass type you are referencing based on your description.

It is a glass pattern that has been in use for many years and is often used in outdoor tables, particularly patio tabletops. It is also popular in glass bath enclosures. It is of a nice appearance and cuts easily and tempers well for patterned, obscured glass. It can, however, be difficult to clean because of its uneven surface. You are certainly not the first to be frustrated when its time to clean this glass.

Because this glass is used in outdoor furniture and bathtub enclosures, it gets a different kind of dirt or grime than let’s say a piece of glass in a window or door. Specifically, dirt, grime, soap scum, and any number of other things can accumulate on this glass and it can often be there for a long period before an attempt is made to clean it. Unfortunately, depending on the chemical composition of the debris that is allowed to sit too long on the glass surface, you may not be able to remove it—it can become a permanent stain. However, let’s go thru some things you can try to do.

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NOTE: BEFORE YOU DO THE FOLLOWING PROCEDURES, BE SURE YOU READ THE LABELS (INCLUDING THE WARNINGS) ON ANY AND ALL PRODUCTS YOU USE. WEAR RUBBER GLOVES, EYE, AND SKIN PROTECTION AND ALWAYS WORK IN WELL VENTILATED AREAS. BE CAREFUL!

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1. Before we attempt anything too specific, let’s really clean the glass with a good soapy solution using hot water and a little elbow grease. Scrub the glass and rinse it thoroughly. You may also want to experiment with the following suggestions in small areas to see if they are going to be effective before attacking the entire glass surface.
2. When the glass is dry (after the soapy water cleaning) apply some CLR® Calcium Lime and Rust Remover liquid to a rag and start attacking the stains. Use the CLR liberally and if at first it is not doing anything, let it sit for a while, hoping that a good soaking will loosen whatever it is that is causing the “ghost rings.”
3. If the CLR doesn’t work, try a product known as Barkeeper’s Friend. This will require a little scrubbing but it can be quite effective. Make sure you keep your solution wet enough to make a slurry type paste out of it. Again, try a test area to see if it is working before using it over the entire glass top surface.
4. If we are still not winning the battle, let’s try a product called “Ceramic Stove Top Cleaner.” Follow the instructions on the container carefully and as we have suggested above, do a test area to see if this works.

Now, if none of the above works, it is probably going to be because the glass has become permanently stained (etched) and then the solution is to replace the glass with a new piece of glass (your local glass shop can handle this for you) or put some type of a table cloth over the stained glass. I can tell you that I have personally seen all of the above procedures do the trick, but I have also seen glass that is too stained for anything to work on it. I am going to hope that you can make one of the above work for you and if you don’t mind, would you please let us know how this all works out for you. We’ll keep our fingers crossed. Thank you again for making contact with the Glass.com Glass Detective and good luck!

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By Lyle Hill

Lyle Hill has been in the glass and metal industry for more than 40 years. In this time he has managed glass retail, contract glazing, mirror, architectural window, window film, and automotive glass businesses throughout America. He obtained an MBA from IIT with a focus on Technology and Engineering Management.

Hill is also a columnist for glass industry trade magazines and often called the “face” of the glass industry. He has also authored books including “The Broken Tomato and Other Business Parables,” which is available through Amazon.