Heat resistant plaster

[Blacksmith105]

I have installed a 6kw wood burner and had the wall behind it plastered with heat resistant plaster . However finish is awful and very rough , can I get it RE skimmed over the heat resistant plaster. I have tried sanding it and used light filler but still finish is rough. You can see it when light shines on it as looks very rough . It's basically the wall behind the stove

 

[The Hobo]

I have installed a 6kw wood burner and had the wall behind it plastered with heat resistant plaster . However finish is awful and very rough , can I get it RE skimmed over the heat resistant plaster. I have tried sanding it and used light filler but still finish is rough. You can see it when light shines on it as looks very rough . It's basically the wall behind the stove

lights shining down plastered walls you will always find imperfections /although going off your filling spots seems a rough job anyway over skim might blow off

 

[Mouldyoldspudgun]

God that s**t is horrendous top coats like self levelling compound to put on