Ceramic Coating as a Thermal Barrier
A high-temperature ceramic coating acts as a thermal barrier, keeping heat inside an exhaust and reducing the temperature of the outer surface. In manufacturer testing on a heavy-duty truck exhaust, C-7300 Black Velvet ceramic coating reduced the outer skin temperature by 38% at 1,050°F and 52% at 1,540°F, with no loss of gloss, colour or adhesion.
What is a thermal barrier coating?
High-temperature ceramic coatings are durable, heat-resistant finishes that resist corrosion and wear, reduce oxidation of the metal and act as a thermal barrier. On an exhaust, that means less heat radiated into the engine bay and onto nearby components.
C-7300 Black Velvet is one of the most popular high-temperature coatings, thanks to its deep jet-black satin finish. It’s widely used on headers and exhaust components for motorcycles and cars.
The test: a Class 8 truck exhaust
Cerakote (NIC Industries) tested C-7300 Black Velvet on a coated Class 8 heavy-duty truck exhaust stack. The exhaust gas was cycled through temperatures typical of real-world use:
- At 1,050°F (held for 30 minutes): the outer skin ran around 400°F cooler than the exhaust gas, a 38% temperature drop.
- At 1,540°F (held for 30 minutes): the outer skin ran around 800°F cooler than the exhaust gas, a 52% temperature drop.
After testing, the coating showed no change in gloss, colour or adhesion, and no signs of degradation at elevated temperatures.
Figure 1: the coated Class 8 exhaust stack used in testing.
Figure 2: exhaust gas temperature compared with skin temperature at 1,050°F and 1,540°F.
What this means for your exhaust
The same principle applies to car and motorcycle exhausts, manifolds and turbos: a ceramic coating keeps more heat inside the system, lowers under-bonnet temperatures and protects the metal. See our ceramic coated exhausts, manifolds and turbos pages, or browse the C Series colour range.
Dual-stage clear coat testing on aluminium
NIC Industries also tested a dual-stage ceramic clear coat (MC-156) on two types of aluminium panel: untreated aluminium (Sample A) and chrome-treated aluminium (Sample B). After curing to specification, the panels went through a full set of quality control tests: adhesion, impact, mar resistance, pencil hardness, solvent resistance, salt spray, humidity, water immersion, thermal shock and CASS testing. Average film thickness was 2.7–2.8 mils for Sample A and 2.5–2.6 mils for Sample B. The results are shown in the table below. For polished alloy parts, see our ceramic clear coat page.
Test data source: Cerakote / NIC Industries, Inc. For more test results, see our ceramic coatings technical report.
For a quote, call 01621 841100 or email msb@msbpcl.co.uk.
Thermal Barrier FAQs
How much does ceramic coating reduce exhaust temperature?
In manufacturer testing on a truck exhaust, C-7300 Black Velvet reduced outer skin temperature by 38% at 1,050°F and 52% at 1,540°F.
Does ceramic coating lose its colour at high temperatures?
In the same test, C-7300 Black Velvet showed no change in gloss, colour or adhesion after being held at 1,540°F.
What is a thermal barrier coating?
A coating that keeps heat inside a component, such as an exhaust, reducing its outer surface temperature and the heat radiated to nearby parts.