posted on August 23, 2012 08:58
Headers and Exhaust Manifolds consist of cast iron, factory manifolds or a steel tube header used in high performance applications and also in OEM applications. These exhaust manifolds and headers need a high temperature protective coating that will resist rust, corrosion and high temperatures.
As with any coatings application, adhesion is a function of surface preparation. Proper surface preparation often requires sandblasting or mechanically grinding the surface prior to applying the primer and top coat or in some cases, two coats of the same high temperature coating.
Headers can be painted after sand blasting, mechanical grinding and then a solvent clean with xylene or acetone prior to painting/coating. Header paint can be purchased in black, available and custom colors.
After the coating is applied, the solvent evaporates and the coating will then cure / dry once heated based on the technical data sheet under curing or drying time. These coatings are made up of silicone or silicone ceramic. The ceramic coatings need to see extreme temperatures in order for the paint to cure properly and if the coating does not reach these elevated temps, the coating will not dry completely and not reach full properties.
A header paint will withstand between 800-1400F. After temperatures that exceed 1600, the metal will then form what is called mill scale and will then lift the coating off of the metal. The paint will then peel of the substrate like dry and blistering paper. The paint may also start to discolor, fade and chalk. This failure will also be determined on surface preparation, application and, the thickness of the metal substrate and how hot the engine is running.
Choosing the right coating system for your engine, exhaust and header can be challenging. Contact a reputable high temperature paint manufacturer to discuss the application whether you are an exhaust, header, catalytic converter or engine manufacturer to a auto enthusiast, restorer or race car industry specialist and they will hopefully help you from design, color to application.