Smoke on high temp paint

[voucht]

Hi,

I have started my engine today. First time with the exhaust manifold I modified.

I painted this manifold and the tube with black high temperature paint (650°C).

When I ran the engine today, when it started to heat up, the manifold was smoking a lot from everywhere, a bit like if the painting was burning.

I preferred to stop rather than wait and set up a fire.

Is it normal to have smoke on the paint the first time it is used? Perhaps it is smoking a lot at the beginning, and then stabilizes after a while?

Or did I use a wrong paint, 650°C not being enough?

Thank you for your help.