draftgli
Go Kart Champion
- Location
- Rochester, NY
- Car(s)
- 2017 GTI Sport
…and found white stains on your paint and/or glass, this is for you:
My wife and I went to the USO in nyc. Parked the car in a garage for 3 days. When we picked the car up, noticed a bunch of white droplets on the windshield, glass, and paint. Didn’t think much of it at the time. Car was overdue for a coat of wax anyway, so I figured I would tackle it in the coming days. Well, after washing, clay bar, machine polishing, and vinegar…I was at a loss as to how to remove these defects. They wouldn’t budge. I was considering filing an insurance claim. But, after a bit of research, thankfully I was able to do the job myself.
I’m no chemist, but my understanding is acid is one way to remove stains like these - which are essentially moderate to severe hard water stains (which are usually very alkaline, thus the hazy white color and the difficulty to remove with traditional methods). Here’s what I came up with:
Glass:
Cerama Bryte - yes, this is a stovetop cleaner. It contains citric acid. From everything I can tell, this is perfectly safe to use on glass - including the windshield. I did all the glass by hand. Significant elbow grease with a microfiber towel will be required, but it will eventually come off.
Paint:
Acid wheel cleaner or diluted muriatic acid. I had the former laying around, so I used that. A couple of important notes here. Be conservative with your dilution. You do not want to put full strength (or anywhere near) acid on your paint. If you are mixing water and acid, NEVER pour water into acid. Instead pour the acid into a container of water (yes you can use plastic). Wear gloves, eye protection, and long sleeves. DO NOT do this in direct sunlight. DO make sure you are in a well ventilated area. DO NOT DO THIS AT ALL anywhere near any areas where there is rust or any apparent damage to the clearcoat. The acid WILL leach in there and continue eating away the clear from underneath. Finally, I would strongly encourage not using this method on glass - particularly on the windshield. You may get away unscathed. But acid can etch glass - particularly the stronger ones. I did try a small spot area on the drivers side window. But the Cerma Bryte was more effective. YMMV. Regardless, be careful.
When you’re ready, here’s what you do. Soak (or spray onto) a microfiber towel a small amount of your acid solution. GENTLY rub the solution over the soiled area (preferably in the direction the air would flow over the car when driving forward). Do not use a circular motion - back and forth only. Allow to dwell for 30 seconds. Be ready with waterless wash or QD and another CLEAN microfiber towel. Wipe the area down thoroughly. Repeat if necessary. When all spots are removed, rinse the car THOROUGHLY. If you wish, for peace of mind, you could hose down the areas worked on with APC to neutralize any remaining acid you may have missed. I chose not to, feeling relatively confident I had worked in small enough areas that I had prevented acid from getting everywhere. Now wash the entire car THOROUGHLY. A good old fashioned 2 bucket method is called for here IMO. Dry the car with clean towels. Inspect for any areas you may have missed. If the defects are gone, proceed to clay and polish if necessary. Finally be sure to apply LSP, as the acid will have stripped any protection off your paint.
Hope this helps someone.
My wife and I went to the USO in nyc. Parked the car in a garage for 3 days. When we picked the car up, noticed a bunch of white droplets on the windshield, glass, and paint. Didn’t think much of it at the time. Car was overdue for a coat of wax anyway, so I figured I would tackle it in the coming days. Well, after washing, clay bar, machine polishing, and vinegar…I was at a loss as to how to remove these defects. They wouldn’t budge. I was considering filing an insurance claim. But, after a bit of research, thankfully I was able to do the job myself.
I’m no chemist, but my understanding is acid is one way to remove stains like these - which are essentially moderate to severe hard water stains (which are usually very alkaline, thus the hazy white color and the difficulty to remove with traditional methods). Here’s what I came up with:
Glass:
Cerama Bryte - yes, this is a stovetop cleaner. It contains citric acid. From everything I can tell, this is perfectly safe to use on glass - including the windshield. I did all the glass by hand. Significant elbow grease with a microfiber towel will be required, but it will eventually come off.
Paint:
Acid wheel cleaner or diluted muriatic acid. I had the former laying around, so I used that. A couple of important notes here. Be conservative with your dilution. You do not want to put full strength (or anywhere near) acid on your paint. If you are mixing water and acid, NEVER pour water into acid. Instead pour the acid into a container of water (yes you can use plastic). Wear gloves, eye protection, and long sleeves. DO NOT do this in direct sunlight. DO make sure you are in a well ventilated area. DO NOT DO THIS AT ALL anywhere near any areas where there is rust or any apparent damage to the clearcoat. The acid WILL leach in there and continue eating away the clear from underneath. Finally, I would strongly encourage not using this method on glass - particularly on the windshield. You may get away unscathed. But acid can etch glass - particularly the stronger ones. I did try a small spot area on the drivers side window. But the Cerma Bryte was more effective. YMMV. Regardless, be careful.
When you’re ready, here’s what you do. Soak (or spray onto) a microfiber towel a small amount of your acid solution. GENTLY rub the solution over the soiled area (preferably in the direction the air would flow over the car when driving forward). Do not use a circular motion - back and forth only. Allow to dwell for 30 seconds. Be ready with waterless wash or QD and another CLEAN microfiber towel. Wipe the area down thoroughly. Repeat if necessary. When all spots are removed, rinse the car THOROUGHLY. If you wish, for peace of mind, you could hose down the areas worked on with APC to neutralize any remaining acid you may have missed. I chose not to, feeling relatively confident I had worked in small enough areas that I had prevented acid from getting everywhere. Now wash the entire car THOROUGHLY. A good old fashioned 2 bucket method is called for here IMO. Dry the car with clean towels. Inspect for any areas you may have missed. If the defects are gone, proceed to clay and polish if necessary. Finally be sure to apply LSP, as the acid will have stripped any protection off your paint.
Hope this helps someone.
Last edited: