How is “hydrophobic” measured?
By the angle a water droplet makes where its edge meets the surface. A 2024 paper in Micromachines gives the bands materials scientists use:
| Water contact angle | Classed as | What water does |
|---|---|---|
| Below 90° | Hydrophilic | Spreads and wets the surface |
| Above 90° | Hydrophobic | Pulls into beads |
| 150° to 180° | Superhydrophobic | Beads almost completely and rolls off easily |
The same paper describes the self-cleaning side of very high angles, the “lotus effect”: droplets roll off “carrying away contaminants and dust particles.” A finish only has to pass 90° for water to bead on it.
Where do hydrophobic surfaces show up on a car?
On coatings, on film and on some glass. Brookswood Tint describes its graphene-ceramic coating’s finish simply: water beads and rolls off, taking dirt and grime with it. LLumar builds the same behaviour into its PPF top coats: Platinum Matte uses HydroGard, “a hydrophobic topcoat that repels moisture,” and Valor is sold as “super hydrophobic.”
Glass can be made water-repellent at the factory too. AGC sells water-repellent door glass with a “highly water-repellent and durable fluorinated coating” for clearer side windows in rain. Windshields with cameras are a different case: Subaru’s EyeSight bulletin says no water-repellent treatment belongs on either face of those windshields, so check yours before booking a glass coating.
What wears hydrophobic behaviour down in BC?
Chemistry and washing, mostly. LLumar’s PPF lineup page footnotes its hydrophobic claims: their durability and level “can be influenced by environmental conditions” such as “road treatment chemicals and cleaning substances/frequency.”
Both are a fact of life here. TranBC says highway contractors spread salt, brine, anti-icing products and abrasives in winter, and Abbotsford, Langley’s neighbour, logs 179.5 wet days and a yearly precipitation total of 1,537.8 mm in Environment Canada’s climate normals. If you’re judging a coating by its beading, do it on a freshly washed panel; checking whether a coating still works walks through the test.
Coatings at the shop come as Essential, a single layer; Performance, a pair of layers after two-stage correction; and Signature, four layers once the paint is fully corrected. Each is quoted per vehicle on the ceramic coating page. Plan on 1 to 3 days in the shop, then a full day without the car getting wet once you collect it.
