The Professional Guide to Paint Decontamination

Ensure the vehicle panels are cool to the touch. In Australian summer conditions, this usually means working before 9:00 AM or after 5:00 PM. If the paint is hot, chemicals will flash (dry) instantly, leading to permanent staining or streaking of the clear coat. Use an infrared thermometer if available; panels should be under 30°C.

Position the vehicle under a carport or professional gazebo. Working in direct sunlight during the decontamination phase is the primary cause of product failure. Ensure you have adequate ventilation as iron removers contain ammonium thioglycolate, which has a strong, pungent odour.

Blast the vehicle thoroughly with high-pressure water. Focus on wheel arches, window seals, and trim gaps where red dust and salt accumulate. This removes loose grit that would otherwise be dragged across the paint during the contact wash, preventing 'swirl marks'.

If using concentrated soaps or APCs (All Purpose Cleaners) for the pre-wash, mix them according to the manufacturer's 'heavy duty' ratio. For Australian conditions where red dust is present, a slightly stronger alkaline mix (pH 10-11) is often necessary to break the static bond of the dust.

Perform a thorough contact wash using the two-bucket method. Use a high-alkaline soap or add 30ml of APC to your wash bucket. This 'strips' any existing waxes or sealants, exposing the bare paint and the contaminants embedded within it. Rinse thoroughly from the top down.

Dry the vehicle using a dedicated drying towel or air blower. While it seems counter-intuitive to dry a car you are about to get wet again, iron removers work most effectively on dry surfaces. Water on the panels dilutes the chemical, reducing its ability to react with iron particles.

Spray the iron remover liberally over the entire vehicle, working from the bottom up (where most fallout sits). Let it dwell for 3 to 5 minutes. You will see a 'bleeding' effect as the clear liquid turns purple. This is the chemical reaction dissolving sintered iron brake dust and industrial fallout.

On heavily contaminated areas (like the rear bumper or lower doors), use a damp microfibre applicator to gently agitate the purple liquid. This ensures the chemical reaches the base of the embedded particle. Do not let the product dry; mist with a little water if it begins to evaporate.

Rinse the vehicle twice. Iron removers are acidic/salt-based and can cause corrosion if trapped in window seals or badges. Use high pressure to flush every crevice until the water runs completely clear with no purple tint.

Inspect the lower panels for black spots (tar) or amber droplets (sap). Spray a solvent-based tar remover onto a microfibre cloth and dab the spots. Let it sit for 60 seconds, then wipe away. Solvent reacts quickly; do not leave it on plastic trims as it can cause discolouration.

Re-wet the vehicle. Prepare your clay bar by kneading it into a flat pancake shape. If using a clay mitt, ensure it is thoroughly rinsed in a bucket of clean water. Prepare your dedicated clay lubricant in a spray bottle.

Working in 50cm x 50cm sections, spray plenty of lubricant onto the panel and the clay. Using light finger pressure, glide the clay across the surface in straight, overlapping lines (never circular). Initially, you will feel resistance and hear a 'hissing' sound—this is the clay catching on contaminants.

Continue gliding until the clay moves silently and smoothly. Periodically check the face of the clay bar. If it looks brown or grey, fold it over to reveal a fresh, clean surface. Using dirty clay will scratch your paint. If you drop the clay on the ground, discard it immediately.

Perform a final rinse to remove lubricant residue. Dry the car and inspect the paint by feeling it through a thin plastic sandwich bag (the 'baggie test'). If the paint feels perfectly smooth like glass, decontamination is complete. If it feels gritty, repeat the claying step on those sections.