High temperature paint for protection from heat
When a substrate is subject to heat and rapid, extreme temperature fluctuations, it can lead to surface breakdown, coating failure and corrosion. Electrical and engine components, chimneys and ovens, pipework and chemical plants, all these are exposed to possibly damaging temperatures and conditions. A high temperature paint (also heat resistant paint or heat proof paint) works to protect the substrate from fluctuation and extremes of temperature without losing functionality. From historic Australian trains like the Cockatoo Run to pipeline protection and mining uses, high heat paint finds many applications across Australia.
The top 5 advantages of heat resistant paint are:
- Effective temperature range up to 1000°C: Different formulations provide resistance to heat from -196°C to 1000°C
- Reduce thermal fatigue: improve performance of machinery and extend part life
- Allow for higher operating temperatures: while limiting thermal exposure
- Abrasion resistant: Suitable for harsh environments
- Protect from corrosion under insulation (CUI): Provides an extra layer of protection between the hot surface and insulation
In this article we look at the different categories of high temp paint, how to choose the right one for your project, and where to find products and services in Australia.
Combat CUI with heat resistant paint for steel
Insulating metal structures is very common in industrial environments; it minimises heat gain or heat loss, reduces costs, improves efficiency, and increases staff safety. The problems start when water penetrates the insulation, collecting in the space between the insulation and the metal. This provides a perfect environment for corrosion. The trapped moisture has the potential to cause rapid rusting and corrosion on the surface of the steel, below the insulation layer.
CUI is particularly insidious as it can go undetected under insulation until the problem is severe. If it remains undetected, it can lead to shutdown of an entire facility, or even safety incidents. This is why a heat resistant paint for steel is so important – it can coat the steel or other metal surface and protect it from the hazard of corrosion under insulation.
Four most common types of heat proof paint
It is important to note that while high temperature paint does provide some protection from flames, they are not fire resistant coatings. Essentially, heat proof paints can be divided into four types:
1. Epoxy- or silicone-based, multi-polymeric paints
Single or two component, water- or solvent-based, these paints are formulated to provide resistance to high heat when applied at new construction, on-site and as a maintenance coating. Usually the more silicone, the higher the temperature resistance. For medium to high temperature protection for example on machinery parts. Liquid heat proof paint has the benefit of being able to be applied to hot substrates without affecting the coating.
2. High temp powder coating
As well as being corrosion resistant, high temperature powder coating has been developed for heat resistance to temperatures ranging from 200°C to 550°C. The powders are usually epoxy and silicone-based (like the liquid paints), and silicone-based powders perform better at higher heats. These have the benefit of being VOC free and having a wide range of gloss and colour finishes.
3. Sprayed metal and metal additive coatings
These coatings are particularly used for corrosion protection combined with heat resistance. Thermal sprayed aluminium is particularly used for CUI prevention in onshore and offshore platforms and processing plants. Metal pigments are often used as stabilisers for temperatures above 400°C.
4. High temp ceramic paint
The heat resistance properties of ceramic coating are well known, and some of the highest temperature paints available are ceramics. They also provide corrosion protection and chemical resistance and a hard finish. With high temperature ceramic paint, insulation and the metal under it can also be protected.
How to choose a temperature resistant paint
As with any coating application, understanding the needs of your substrate and the application process is crucial for making the right coating choice. As well as knowing the substrate type, you need to know its environment, its use, the coating time parameters, and the likely ways it will fail. Here are some questions you need to ask before you can choose a high temperature paint:
- Substrate temperature during application:
There are high temperature paints formulated for hot (up to 300oC) and room temperature application. A hot application may be required to avoid downtime, spot coating problem areas, and generally not disrupting a facility.
For example, Jotun Epoxy HR can be applied on substrates up to 150oC
- Maximum temperature of the substrate:
One of the most common reasons for failure is expecting these coatings to perform outside of the temperature range they were manufactured to tolerate – they may be called heat proof paint but there are limits. Each coating type has a specific temperature range, and outside it the functionality and efficacy fails. Make sure not to understate the maximum temperature.
For example, International Intertherm 50 is recommended for temperatures up to 540°C.
- Insulation of the substrate:
If you are choosing a coating to combat CUI, that coating needs to be specially formulated for the purpose. It needs corrosion resistance, but it also needs to be able to be applied to hot substrates and deal with boiling water exposure.
For example, PPG HI-TEMP 1027 is designed to prevent CUI and can be applied to hot substrates
High temperature paint Australia: specialists & products
High temp paint is used across a wide range of industries, as well as by homeowners and barbecue enthusiasts. As such, a wide range of products and services are available across the country, no matter your project. Below is a table outlining just a few of the products and an indication of their costs. These coatings should be applied by a trained professional but when it comes to high temperature paint, Australia has you covered. If you would like more information about heat resistant coating, or would like to connect with one of our partners to coat your project, contact us! Our experts are happy to help, just use the “request a quote” button below the article and make use of our 100% free quote service.
|Heat resistant paint product||Price (RRP)||Packaging||Applications|
|White Knight Heat Resistant Paint||$31.90||500ml||metal surfaces|
|Scandia High Temp Enamel||$24.90||400g||metal surfaces|
|Car-Rep Heat Resistant Spray Paint 600 degree||$24.99||400ml||external metal surfaces|
|Dulux Duramax High Heat Enamel||$49.98||300g||barbecues, stoves and lamp shades|