The Professional Guide to Water Spot Removal and Mineral Decontamination (Jan 2026)

Perform a thorough two-bucket wash using a high-pH strip soap to remove old waxes and sealants. This ensures the water spot remover can interact directly with the mineral deposits rather than sitting on top of a sacrificial layer. Pay extra attention to window seals where minerals often hide.

Using a fine-grade clay bar and ample lubricant, move the bar over the affected areas. You are looking to remove the 'above-surface' portion of the water spot. In the heat, ensure the panel is cool to the touch; otherwise, the clay may mar the paint or stick to the surface.

Dry the vehicle completely using a dedicated drying towel or forced air. Use a high-intensity LED torch (or the sun at a 45-degree angle) to categorise the spots. If they disappear when wet but reappear when dry, they are Type I (topical). If they look like small craters, they are Type II (etched).

Move the vehicle into a shaded garage. Check the panel temperature using an infrared thermometer. The surface must be below 30°C. In an Australian summer, this may require performing the work at 6:00 AM or after 7:00 PM to avoid flash-drying of acidic chemicals.

Apply a small amount of acidic water spot remover to a microfibre applicator. Work a 20x20cm area on a lower panel. Let it dwell for 30-60 seconds, but do not let it dry. Rinse thoroughly. This checks for any adverse reactions with the specific paint system or trim.

Apply the remover in a cross-hatch pattern over the affected area. The acidity works to break the bond between the calcium/magnesium and the clear coat. Work in small sections (no larger than half a bonnet) to maintain control over dwell time.

Use light finger pressure with a microfibre towel to agitate the chemical. This helps the acid penetrate the microscopic 'pores' of the paint where minerals are lodged. You may notice a slight 'fizzing' or white residue as the reaction occurs.

Rinse the area with a heavy stream of water. It is critical to neutralise the acid. Professionals often follow this with a quick wipe of a high-pH soap or a dedicated neutralising agent to ensure no acidic residue remains in the crevices.

Dry the section and inspect with your LED light. If the spots are gone, proceed to protection. If a 'ghost' or 'crater' remains, the minerals have etched the paint (Type II), and you must move to mechanical leveling (polishing).

Apply 4-5 drops of fine finishing polish to a foam polishing pad. Spread it evenly across the pad face. This ensures consistent abrasion and prevents 'dry buffing' which can generate excessive heat on sensitive clear coats.

Using a DA polisher on speed 3-4, perform 4 slow passes over the etched area. Use overlapping paths. The goal is to remove a microscopic layer of clear coat (usually 1-2 microns) to level the 'craters' caused by the etching.

Periodically touch the panel. If it feels hot to the hand, stop and move to a different panel. High heat can soften the clear coat, making it prone to 'sticky paint' syndrome where the polish becomes difficult to remove.

Wipe away polish residue with a clean microfibre. Spray a 15% IPA solution onto the panel and wipe again. This removes the polishing oils that might be 'filling' the water spots, giving you a true view of the surface.

Check the surface at multiple angles. If the etching is still visible, a second round of polishing with a slightly more aggressive compound may be required. However, always prioritize clear coat thickness over total spot removal.

Water spots on glass can be treated with the same acidic chemical. If they persist, use a dedicated glass polish (Cerium Oxide based) and a felt pad. Glass is much harder than paint and can withstand more aggressive mechanical action.

Perform a final rinse of the entire vehicle using distilled or deionized water. This ensures that no new minerals from your tap water are left to dry on the freshly corrected and 'naked' paint surface.