What is Silicon carbide (SiC)?

Silicon carbide, often written as SiC, is a hard, man-made ceramic made from silicon and carbon. In its “proper” engineering form it’s incredibly tough, very heat-resistant and highly resistant to wear and chemicals. Because of this it’s used in demanding applications like grinding wheels, cutting tools, brake discs and even armour plating – anywhere you want something that’s close to diamond in hardness but practical to manufacture.

In car care, you’ll sometimes see SiC mentioned in connection with modern ceramic coatings. That doesn’t mean you’re sticking lumps of sandpaper or brake disc onto the paint. Instead, the coating chemistry is based on tiny silicon- and carbon-containing molecules which cure to form a very thin, glass-like protective layer. The “SiC” label is really telling you about the type of ceramic network inside that layer, not that the car now has a solid block of engineering silicon carbide on it.

How SiC fits into modern ceramic coatings

When you see silicon carbide or SiC mentioned on a coating data sheet, it is describing how the ceramic network inside the coating has been tuned. You are still getting a very thin, glass-like layer on top of your clear coat rather than a solid lump of engineering silicon carbide. The chemistry uses silicon and carbon containing building blocks to give extra hardness, stability and resistance to chemical attack compared with a basic entry level ceramic.

Think of it as a more highly engineered version of the same idea. You still have a sacrificial layer on top of the paintwork that takes the brunt of the wear so your clear coat does not have to.

What SiC-labelled coatings actually change

The jump from no coating to a good quality ceramic is huge. The jump from a good conventional ceramic to an SiC based ceramic is smaller, but it is there and tends to show up in tougher conditions.

• Hardness and scratch resistance – SiC based coatings aim to be more resistant to light wash marring and the kind of faint swirls that come from regular contact washing.
• Stability in heat and UV – the chemistry is designed to cope better with strong sun and high panel temperatures, so the coating stays clearer for longer on cars that live outside.
• Chemical resistance – they tend to shrug off bird mess, insect remains and traffic film a little better, giving you more time to deal with accidents before etching marks the surface.
• Optical clarity – most premium SiC coatings are very clear and high solids, which helps add that sharp, three dimensional gloss you expect at the top end of the market.

Limits and marketing myths

SiC coatings are still subject to the same basic physics as any other ceramic coating, so it helps to be realistic about what you are buying.

• They cannot stop stone chips, deep scratches or car park dings. If you need impact protection, you are in paint protection film territory.
• They do not make the car maintenance free. You still need sensible wash technique, mild chemistry and the occasional decontamination to keep the coating performing at its best.
• They will not fix poor polishing work or a bad respray. Preparation still does most of the heavy lifting. If there are sanding marks, holograms or texture in the clear coat, the coating will simply lock them in.
• They are not permanent in the literal sense. A good SiC coating is very durable, but it is still a wearing layer and can only be removed cleanly with machine polishing or similar abrasion.

When an SiC coating is worth considering

Because SiC coatings sit at the premium end of the market, they make the most sense when the rest of the package matches.

• You plan to keep the car for a long time and want to preserve a high standard of finish rather than just making it look nice for a year or two.
• The car lives outside, does plenty of miles or spends time on fast roads where it sees lots of grit, grime and bug splatter.
• You are having extensive paint correction carried out and want the toughest sensible sacrificial layer on top of that investment.
• You are happy to follow an agreed aftercare routine so the coating is given a fair chance to perform to its potential.

Choosing an installer and asking the right questions

SiC coatings are professional products, so it is worth treating the choice of installer as seriously as the choice of coating.

• Ask which specific SiC coating they are using, who makes it and why they recommend it for your car and usage.
• Get a clear explanation of the preparation work included – wash, decontamination, machine polishing and any smart repairs that may be needed first.
• Have them talk you through what the warranty really covers and what counts as fair wear, including any inspection schedule.
• Discuss aftercare in plain English – which shampoos to use, which products to avoid and how often they expect you to wash the car.
• Be honest about where the car is kept, how often it is washed and how fussy you are, so the coating package can be matched to you instead of just following the brochure.

Written by Danny Argent. Last updated 27/11/2025 15:28