Application protocol
Why chemistry comes first
11 minEstimated reading time — roughly how many minutes it takes to read at a normal screen pace.
- Why the chemical phase must precede mechanical decontamination.
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Why chemistry comes first
Iron particles and asphalt embed in the film on the paint. If you “wipe” them with clay dry, the abrasive core creates micro-cuts (marring — micro-scratches from wiping). The chemical phase breaks the bond between contaminant and paint.
Fallout (iron)
Reductive iron removers react with iron oxides; you often see purple colouration (indication). Product works in controlled time, then rinse thoroughly.
Interactive diagram
Iron remover reaction progress
Use the slider to simulate iron chelation. Purple staining indicates reaction — follow datasheet dwell and do not let the product dry on the panel.
Full indication
Typical purple signals chelation / reduction — hold the prescribed dwell time and prevent drying.
Purple layer = reaction indication (simplified)
Note: odour of reductive products is chemistry-driven — work in ventilated space (see SDS).
Tar, pitch, adhesives
Bituminous components are non-polar — removed with solvents in tar/glue removers. Apply spot-wise on the stain, let soften, wipe gently, immediately neutralise excess, then continue with neutral wash.
Materials and compatibility
Check SDS and label: some solvents are unsuitable on fresh paint, PPF, or cheap plastics. When in doubt, test on a hidden area.
Order of steps
Recommended step order
Pre-wash + contact wash
Remove bulk layer before targeted chemistry.Iron remover
Rinse per SDS — no drying.Tar remover
Spots only, then rinse and neutralise excess.Mechanical phase
Only then clay with lubricant — see Mechanical decontamination: clay and marring.
Key takeaways
- Chemistry before mechanics — clay on undecontaminated paint is the fastest route to marring.
- Iron remover indicates reaction by colour; do not let it dry; follow prescribed time.
- Tar remover belongs on spots, not full panels — solvents are not compatible with everything nearby (PPF, fresh coatings, cheap plastics).
- Always check SDS and test on a hidden area when unsure.
Further reading
Topic: Prep & washing
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