Sanding & Decorating around new sash window

[nero44]

Hello Everyone,

I have just had a full bathroom remodelling done, including complete skimming of all walls. I have also had a new box sash window installed.

Unfortunately, I was unable to time the installation as these were two different companies, so the sash window could only be installed after the bathroom was fully decorated. The window fitters have generally done a nice job, but left quite a generous amount of filler around the frame. Looking at it form the side, there is about a 1cm "slope" leading up to the frame. I've tried to depict this on the picture below.

Rather than just painting over it, I would like to sand this down a bit to have a cleaner look around the frame.

Is this possible at all and can this be done with an orbital sander etc? Or would it risk making the surface even worse? I would probably look to hire a decorator to do this.

 

[Chivas69]

Do you know what they've filled it with?
I think it can be sanded but I would then recommend neatening it up with some polyfilla or equivalent sanding it smooth. Obviously then the wall will need painting again.

 

[nero44]

Update for anyone who might be facing a similar issue: the filler used was impossible to sand down. It probably contained some cement or mortar. I had a decorator tackle this and they had to partially remove the filler again, refill and then make good. It now looks proper and flush against the wall.