Does anyone know of any sort of spray or paint on thermal barrier that can be applied in house to Al stock? Something similar to Rino-Lining to apply, and significantly reduces heat transfer.
There are several ceramic filled products out there that do exactly what you describe. Do a search for ceramic filled heat resistant coating, you may find a few to test in you application.
The expanding foam will either hold in heat or keep it out. I understood the substrate to be aluminum and the goal is to transfer the heat from the substrate. More details on what you need the coating to do would be appreciated. The ceramic fillers will provide the durability you desire and act as an insulator, too.