Water doesn’t leave marks or etch surfaces; it’s the minerals that it contains calcium (Ca) and magnesium (Mg) and reactivity (heat acting as a catalyst) the spots are actually traces of minerals left on the surface when the water evaporates. Alternatively they can be caused by industrial pollution (i.e. acid rain, bird excrement or industrial fallout)
Generally surface water-spots have no raised edges and are very shallow and so cannot be felt, they are very similar to micro-fine surface marring. They cannot be removed from the surface by washing but they can usually be removed with a 1:1 solution of vinegar and distilled water; this acid-based (acetic acid) formula breaks the bond between mineral deposits and the vehicle surface. For minor surface etching use a slightly abrasive chemical paint cleaner
Note: Vinegar is a liquid produced from the fermentation of ethanol in a process that yields its key ingredient, Acetic (Ethanoic) acid, pH 2.7
There are two categories of water mark (See also Calcified Water Marks)
Stage I (Surface) Corrosion
[: defined as a surface with light to moderate corrosion damage to the paint surface]
Stage II (Sub-surface) Corrosion
[: definition when the dirt/corrosion deposits are no longer on the surface but have started to break down the molecular structure, leaving an etched or white haze on the surface( a concave circular mark ) after the stain has been removed, with moderate to serious paint damage]
a) Surface water spots- (Stage I Corrosion) alkaline watermarks consist of calcium (Ca) and magnesium (Mg) both of which are basic (alkaline pH 10) that alight on the surface; ultra violet (heat) radiation (UVR) will leave a white ‘water mark’, the minute crystals bond to the surface, they will not wash off as they are insoluble and if left for any length of time they will etch the paint film surface leaving a concave circular mark, remove surface deposits with detailer’s clay and an acetic acid pH 2.0 (vinegar) to naturalise the alkaline
b) Below surface (etched) spots- (Stage II Corrosion ) are caused by an aggressive alkaline or an acidic solution (acid rain, bird excrement or industrial fallout) causing a chemical reaction, if left for any length of time they will etch the paint film surface leaving a concave circular mark. Unlike water spots which typically have a white outline of the spot, acid rain etching is smaller and you can see the damage in the clear coat.
Inspect the surface etching under magnification, and then you will be able to assess the damage. Magnification will allow you to view paint flaws in perfect detail. View the edges of acid rain or water spot damage, and the hard-to-see depth of scratches. Only then, you will be able to assess the real damage. The edge should be levelled, which will make the etched depression almost invisible.
Etched acid rain spots are one of the most difficult paint defects to remove so be patient as it will probably take more than one attempt to remove them.
Acid spots require an abrasive polish to level the surface (some stubborn marks may require wet sanding) and an alkaline solution to neutralize them, simply rinsing a vehicle with deionised water or tap water activates / reactivates the acid concentrates.
If the surface can be rectified by chemical means then this is the answer; not abrasive polishing. Using the correct chemical cleaners will dissolve the contaminants rather than abrading the surface. With all cleaning products (especially solvents) always test a small inconspicuous area first to ensure it won't discolour, stain or etch the surface, and ensure that the pH of the product is suitable for the material After the paint surface has been subjected to a chemical cleaning its protective layer (s) have been removed and the paint surface left without protection, so it is very important that a polymer and / or Carnauba wax protection be applied immediately
Removing ‘Water spots’
Optimum MDR Mineral Deposit Remover - eliminates the need to use abrasive polishes for the removal of light water spots. Water spots start out as a topical contaminant, but over time they will etch the paint, requiring an abrasive to completely remove. Topical water spots are considered Type 1, and that's the kind Optimum MDR Water Spot Remover is designed to remove.
MDR is designed to dissolve water spots and other mineral-laden water-based contaminants before they etch your vehicle’s paint. This thick and non-abrasive gel formula easily clings to the surface allowing the environmentally safe acids and chelating agents to power through mineral build-up. MDR leaves the surface clean, smooth, and water spot free.
Depending on where you live, you may be all too familiar with the scaly build-up left behind by hard water. Calcium, magnesium, and other naturally occurring minerals in water can harden inside pipes and on to your car. If your vehicle is parked next to a sprinkler, or washed with your garden hose that is hooked up to a water source with high mineral content, you can expect to see that nasty build-up on your vehicle over time. MDR provides a safe and effective way to remove the build-up and save your paint from unsightly etching.
Ideal for use on any hard exterior surface including paint, glass, chrome, and wheels. To use, simply apply a quarter-sized amount to and applicator pad and work into the surface for 30-60 seconds, then wipe away the product residue to check the results. Follow with a thorough wash to remove any additional residue, and then apply your favourite paint protection.
2) Removing etched below surface (Stage II Corrosion) water marks
• These can be removed by using detailer's clay to remove any hardened surface deposits
• Then using a machine polish ( Optimum Polish, Optimum Compound, Zaino Z-PC Fusion Dual Action Paint Cleaner or Swissvax Cleaner ) and a cutting (LC Orange or Yellow) foam pad (speed # 4-5.0 / 1200 RPM ) to level the surface (use the least aggressive polish/foam pad first, if this doesn’t remove the problem step-up to a more aggressive set-up)
• Work on a very small area at a time (2-foot x 2-foot) until the polish has run out
• Repeat this process two or three times, as necessary
• Reapply surface (paint) protection once spots have been removed.
If none of the above methods remove the etched water spots consider wet-sanding the paint finish (See also Glass Polishing article)
To neutralise acid water spots using a polish or compound will remove the etching and the indentations, the below paint surface should then be neutralised ValuGard A B C Decontamination / Neutralization system
If the surface can be rectified by chemical means then this is the answer; not abrasive polishing. Using the correct chemical cleaners will dissolve the contaminants rather than abrading the surface. With all cleaning products (especially solvents) always test a small inconspicuous area first to ensure it won't discolour, stain or etch the surface, and ensure that the pH of the product is suitable for the material
After the paint surface has been subjected to a chemical cleaning its protective layer (s) have been removed and the paint surface left without protection, so it is very important that a paint protection be applied immediately
1. Synthetic steel or bronze wool whatever the grade can leave micro-scratches in the glass, which then become impregnated with road dirt, grit and grime, causing a clouding the glass over time, which impairs visibility.
2. Do not use abrasive cleaner; glass polish or any grade synthetic steel wool on after market-tinted glass or you will probably scratch the surface.
3. For deeply etched water spots (> 0.004 Mil) in the windshield surface, do not attempt to polish them out, consult an automotive windshield vendor as glass or plastic used on later model cars is soft and thin (this may vary by manufacturer) due to weight / cost savings by vehicle manufactures and polishing could cause surface to become badly scratched, stressed or cracked.
4. Be cautious with polishes that contain abrasives like aluminium or cerium oxide as they have the potential to damage glass beyond repair.
5. Some windshields and mirrors have a tinted plastic coating or a blue tint that will scratch or be damaged, only use a glass polish (not synthetic steel or bronze wool) on uncoated glass.
Always be willing to learn; because the more you learn, the more you’ll realize what you don’t know. It is said that knowledge is power, with the caveat that it includes access to a reliable information sources. I would like to think that these articles become an asset to anyone who is new to detailing and to professional’s alike, as well as industry experts who seek to advance their knowledge.
I hope these articles are informative. They are based on the current status of technical development as well as my experience with the products.
By having some understanding of the ‘What’ and ‘Why’ as well as the ‘How’ along with a little science to help you understand how the chemicals we use react, you can achieve the results you desire.
I would appreciate it if you would share these articles as it helps other detailers further their knowledge.
As always if you have questions, I’ll do my best to answer; bear in mind the only stupid questions is the one that was unasked. Questions and/ or constructive comments are always appreciated
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