[Stoves] Black radiating surfaces

[John Davies]

Greetings,

We all know that a black body releases radiation heat the best.

My problem is one of creating a black surface, on a surface that becomes red 
hot.

I have rubbed cooking oil on the surfaces of my gasifier coal stove. This 
burns to a nice mat black colour, and the difference in heat radiation can 
be clearly felt.

However the exposed coal tube will not stay black as the carbon layer 
formed, burns off as the metal approaches red hot temperature.

Is there any other way to achieve a black surface that will not burn off?

Now intuition tells me that there must be a solution to this, possibly some 
black salt which will not melt off, or change it's composition at the 
temperatures experienced.

Does anybody have an answer.

Thanking you,
John Davies.