At Firwin, we are a leading manufacturer of custom insulation products for diesel and gas engines, exhaust systems, and industrial equipment. One of our core product offerings is Hard Coat™ insulation. Below, we outline what it is, its key advantages, technical specs, typical applications, and how it compares to removable insulation.

hard-coat-composite-insulation

What Is Hard Coat™ Insulation?

Firwin Hard Coat™ insulation is a high-temperature composite insulation material. It consists of high alumina, ceramic fiber insulation covered by a highly durable and heat-resistant composite. While the insulating Hard Coat™ing material used in Firwin HC is rated for temperatures up to 2,192 °F (1,200 °C), the product generally sees use in applications involving temperatures 1,200 °F (650 °C) or below.

It is available in 1/2 in. and 1 in. thicknesses, with the 1/2 in. variation rated for continuous use in temperatures up to 1,300 °F (704 °C) and the 1 in. variation rated for continuous use in temperatures up to 1,800 °F (982 °C). The former is more commonly used due to space constraints around parts needing insulation.

Unlike other Firwin insulation solutions (e.g., insulation blankets), Hard Coat™ insulation is non-removeable . As a result, it is not suitable for parts that need regular maintenance.

Advantages of Hard Coat™ Insulation

Compared to other insulation products, Hard Coat™ insulation offers a number of advantages, such as:

  • It forms a hard and rugged exterior. The outer composite layer is less susceptible to tearing and embrittlement, making Hard Coat™ insulation generally more durable and long-lasting than removable insulation blankets.

  • It is resistant to oil and water. The outer composite layer protects the inner insulation layer from fluid intrusion.

  • It is non-flammable. The insulating Hard Coat™ing is self-extinguishing as per FAR part 25.853. The outer composite layer chars when exposed to flames, preventing the flames from penetrating the inner insulation layer and the underlying structures.

  • It is suitable for limited space environments. The insulation product adheres directly and conforms tightly to the part or structure, meaning it takes up less space than other insulation products.

When used correctly, it can offer the following benefits:

  • Mitigation of heat damage on sensitive components
  • Protection against burns
  • Prevention of fluid ignition on hot engine and exhaust parts
  • Lowered ambient temperatures

Applications of Hard Coat™ Insulation

Hard Coat™ insulation is best suited for parts and products that are regularly exposed to high temperatures for extended periods and rarely subject to maintenance and servicing requirements. Some prime examples are engine compartment components, such as elbows, exhaust manifolds, exhaust piping, and turbochargers.

Some of the industries that regularly use Hard Coat™ insulation over removable insulation blankets include:


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Hard Coat™ Insulation vs. Removable Insulation Blankets

The choice between Hard Coat™ insulation and removable insulation blankets depends on how often your equipment needs maintenance access and the conditions it operates in.

Feature Firwin HC™ Hard Coat™ Removable Insulation Blankets
Accessibility Permanently applied; cannot be removed. Designed to be removed and reused; ideal for periodic maintenance.
Durability Solid outer surface; resistant to tearing and punctures in rugged conditions. Silicone impregnated outer surface; may tear or puncture under rugged conditions.
Installation Process Components must be disassembled and shipped to Firwin for coating application. Designed remotely via measurements and photos; components remain with the customer.
Space Constraints Conforms tightly to parts; ideal for limited space. Can be challenging to install and fasten properly in limited space; requires greater clearance.
Fluid Protection Completely encapsulates parts, eliminating the risk of fluid ignition on hot surfaces. Acts as a shield, but some fluid seepage may occur under the blanket.
Flammability Non-flammable (Self-extinguishing per FAR 25.853). Fire retardant.
Relative Cost Higher initial cost (6 to 12 times more) but offers a longer lifespan. More economical upfront cost; lifespan depends on the application and removal frequency.
Common Applications Exhaust manifolds, turbochargers, piping. Exhaust manifolds, turbochargers, piping.Valves, heat exchangers, turbines.

For a deeper comparison of performance, durability, cost, and application fit, read our full breakdown: Hard Coat™ vs. Removable Insulation Blankets.

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Hard Coat™ Insulation Technical Data

Firwin Hard Coat™ insulation is engineered to withstand extreme thermal and mechanical demands. Below are the key property and mechanical data specifications:

Property Data

Continuous Use Limits: 1 in. insulation: 1,800 °F (982 °C) 1/2 in. insulation: 1,300 °F (704 °C)
Flammability Self-extinguishing per FAR part 25.853
Thermal Conductivity in BTU•in/hr•ft²•°F: @ 500 °F (260 °C): 0.48 (0.07 w/m•k) @ 1,000 °F (538 °C): 0.72 (0.10 w/m•k) @ 1,500 °F (816 °C): 1.03 (0.15 w/m•k) @ 2,000 °F (1,093 °C): 1.52 (0.22 w/m•k)

Mechanical Data

Property Laminate Properties
30 PSI (0.20 MPa) cure with postcure Method
Ultimate Tensile Strength
Warp-RT
Fill-RT
47,000 PSI (324 MPa)
42,000 PSI (290 MPa)
ASTM D638, Type 1
42,000 PSI (290 MPa)
Ultimate Flexural Strength
Warp-RT
Fill-RT
78,000 PSI (538 MPa)
69,000 PSI (476 MPa)
ASTM D790
ASTM D790
Flexural Modulus
Warp-RT
Fill-RT
2.6 MSI (18 GPa)
2.6 MSI (18 GPa)
ASTM D790
ASTM D790
Short Beam Shear Strength
Fill-RT
6,670 PSI (46 MPa) ASTM D2344

Hard Coat™ Insulation FAQs

What applications are best suited for Hard Coat™ insulation?

Firwin HC is a permanent insulation, so the first consideration is whether the part in question needs to be accessible for maintenance purposes. If maintenance access is required, a removable insulation blanket would be a better alternative.

Hard Coat™ performs well in confined spaces and completely covers the insulation material. If there are space constraints or if the application involves the possibility of oil coming into contact with the part, Firwin HC may be appropriate. For a detailed comparison, see our resource on Hard Coat™ vs. removable insulation.

How durable is Firwin HC? How long will it last?

Because of the wide variation of demands during use and operation of equipment onto which Hard Coat™ insulation is installed, it is difficult to say precisely how long Firwin HC will last. That said, we designed Firwin HC to offer a durable and long-lasting insulating Hard Coat™ing, and feedback from the field has been generally positive.

Due to the nature of the materials used in manufacturing Firwin HC, some loosening may occur over time during engine use as a result of the expansion and contraction of the engine part as it heats and cools.

What effect, if any, will Firwin Hard Coat™ have on the life of the engine part?

Firwin HC is designed for personnel safety and fire protection of expensive engines and equipment. This is accomplished by insulating exposed high-heat components such as engine manifolds and turbos. There is yet no concrete evidence to confirm whether Firwin HC will reduce the life of an engine part. Although the possibility exists, our customers are willing to assume this risk as it is outweighed by the safety benefits.

Can Firwin HC Hard Coat™ be covered or shielded with other insulation or shielding products?

Hard Coat™ insulation should not be covered or shielded with other insulation or shielding products (i.e., insulation blankets, heat shields, etc.). Any product that retains heat or reflects heat onto Firwin HC can raise the temperature of the outer shell beyond its designed level, thereby causing the outer HC shell to deteriorate.

What thicknesses are available with Firwin HC?

Firwin HC is available in both 1/2 in. and 1 in. insulation thicknesses. Most applications use 1/2 in. thick insulation because of the limited space available around the parts to be insulated.

What is the maximum temperature rating for Firwin HC?

Firwin HC can be used for both high-temperature diesel and gas applications. The insulation material used in Firwin HC is rated at 2,192 °F (1,200 °C). In practice, most applications that use Firwin HC rarely see temperatures above 1,200 °F (650°C), allowing for effective heat reduction from Firwin HC at 1/2 in. insulation thickness.

What is the lead time for Firwin HC?

Firwin HC has a typical lead time of 2 weeks.

How do we ship our parts to Firwin for Hard Coat™ application?

When sending parts:

  • Send the bolt sleeves/spacers as well.
  • Disassemble the turbo. We request that customers send turbos with hot housing only (the air intake side needs to be removed for the HC process). Include clamps if possible.
  • Send plenty of photos of the complete exhaust arrangement. Take detailed pictures anywhere clearance is an issue (within 1 in. of the part).

Are there any customs or border crossing issues that I need to be aware of if sending the parts from outside Canada?

When sending engine parts to Firwin to be coated with Firwin HC, there are certain customs requirements that need to be followed to ensure that there are no delays in getting the parts across the border. A customs invoice and, if shipping from the U.S. or Mexico, a NAFTA certificate need to be prepared and accompany the parts.

What is the warranty for Firwin HC Hard Coat™?

Firwin Corp warrants its products to be free of defects in material and workmanship at the time of delivery. Our warranty is limited to the replacement of the insulation product found to be defective within ninety (90) days from the date of delivery. This warranty is only valid provided the product is used within the design and material limitations for the specific operating conditions, as agreed at the time the order is placed, and is subject to correct installation, regular scheduled inspection, and normal wear and tear.

Visit our Warranty page for more information.

Hard Coat™ Insulation Solutions at Firwin

Hard Coat™ insulation plays an essential role in various industrial applications and processes by protecting employees from burns, preventing the ignition of flammable fluids, mitigating heat damage to nearby components, and lowering ambient temperatures. Additionally, as a permanent insulation solution, it offers better durability and longevity than removable insulation products. If you’re looking for high-quality insulation products, turn to the experts at Firwin.

At Firwin, we provide a wide range of insulation solutions—including Hard Coat™ insulation—for various industrial applications. If you have additional questions about our insulation product offerings, contact us today. To get started on your insulation solution, request a quote.

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