- Home
- Knowledge Base
- Glossary
- High spot (ceramic coating)
High spot (ceramic coating)
Quick answer: A high spot is a patch of ceramic coating that cured thicker than intended because excess residue wasn't levelled off in time. It looks like a smudge, dark patch, rainbow smear or sticky sheen under raking light and usually needs prompt levelling - or light polishing if fully cured.
What it means
During application the coating flashes, leaving a thin film. If product pools, overlaps, or the wipe-off misses an area, that residue "stands proud" and cures as a thicker, uneven patch. High spots disrupt clarity and water behaviour. If caught within the open/flash window they can be re-wet and levelled; once cured they must be abraded and, if needed, re-coated locally.
Why it matters
A high spot is easy to miss on the day and impossible to ignore afterwards. It shows as a smear or a dark patch that only appears at certain angles and in certain light, so it survives the final wipe-down and turns up when the customer walks out to the car.
It is not only cosmetic. A proud patch of cured product traps dust and beads differently from the paint around it, so the panel stops behaving consistently. And the cost of fixing one climbs steeply once it has cured, because what would have been a wipe becomes machine work and, on a stubborn one, a re-coat of the panel.
Where high spots turn up
Edges and overlaps (handles, badges, panel edges), hot or slow-flash conditions, and anywhere section sizes were too large or towels were saturated.
Context
A high spot is an application defect rather than a paint defect. It belongs with levelling, flash time and the two-towel method: the group of terms describing what happens in the minutes between a coating going on and curing hard, when it can still be corrected.
How to fix
- Still within open window (fresh): lightly re-wet the patch with a drop of coating on an applicator, wait a few seconds, then level with a short-nap towel and finish with a second clean towel.
- Just set (minutes to ~1 hour): mist a small amount of the maker's panel wipe onto a towel (not the paint) and massage gently; if unchanged, re-wet with coating as above and level.
- Fully cured: spot-polish the area (fine/medium polish, small pad), panel wipe, then feather a thin re-application to blend behaviour. Protect per cure guidance.
Common mistakes
- Trying to "buff out" a cured high spot with QD - once cured, abrasion is required.
- Over-wiping a large area late, dragging semi-cured product and creating smears elsewhere.
- Working sections too big for the ambient temperature and humidity.
- Using saturated or mixed-fibre towels that leave lint and miss residue.
- Ignoring edges and complex shapes where product pools (badges, handles, panel lines).