Diamond Coating
Quick answer: “Diamond coating” is a marketing term for wipe-on paint protectants, usually silica-based ceramics, that promise diamond-like hardness. It is not real diamond or DLC deposited on paint. Expect a thin, clear coating that improves gloss, chemical resistance and water behaviour, not a scratch-proof diamond layer.
What it means
On cars, “diamond” products are typically polysiloxane/SiO₂ ceramics or polymer sealants with branding that suggests extreme hardness. Some claim “diamond dust” or nano-diamond additives. These particles do not form a fused diamond film and their contribution to durability is minor compared with the coating’s binder chemistry and surface prep. True diamond-like carbon (DLC) or diamond films require vacuum PVD/CVD processes at controlled energy levels and are not achievable with a hand-applied liquid.
Why it matters
- Expectation setting: avoids confusing Mohs hardness claims with pencil hardness or real-world scratch resistance.
- Apples-to-apples comparisons: judge by prep quality, film uniformity, chemical resistance and maintained behaviour, not by the word “diamond”.
- Value: a good ceramic can outperform a weak “diamond”-branded sealant despite the name.
- Safety: the same rules apply as other coatings – correct decon, panel wipe, timing and lighting prevent high spots and rework.
Where you’ll see it
Retail ceramics, dealer “diamond” paint protection packages and some pro-installer ranges that use diamond-themed branding.
Context
Car Paint Protection; Ceramic coatings; Marketing claims
Common mistakes
- Taking “diamond” literally – wipe-on liquids cannot create a true diamond or DLC layer on automotive paint.
- Confusing Mohs hardness with pencil hardness – “9H” on the pencil scale is not Mohs 9 or 10.
- Assuming “diamond dust” makes the coating scratch-proof – technique, prep and film uniformity matter more.
- Skipping surface preparation because the product sounds “ultimate” – poor prep still leads to high spots and weak bonding.
- Applying paint ceramics to windscreens where wiper judder is likely – use a dedicated glass coating instead.