Can you paint exhaust wrap with high temp paint?

Not without a primer or washing the wall with TSP, the flat will not stick to the gloss

Yes, it is advisable to do a light sanding or wash the area with a strong cleanser (TSP works well) to de-gloss the surface.

Painting over just about any sheen is possible. The only thing that I would recommend is to primer the surface 1st for a better application of the eggshell. If you do not primer the surface there may...

Yes, you can generally paint high gloss latex over flat latex paint. But you must do all the preparation work in the best tradition of any professional painter. All "flaking" must be removed and the...

yes you can