Render on underside of Smart Heritage windows

[Piglet89]

The exterior of our property was rendered in November 2024. Some of the render has been applied onto the underside of the sill of our windows. The untidy finish is visible through the lantern skylight in our back extension (see pic) and just the sight of it is annoying me.

Any recommendations for best method to remove the render to leave a clean finish, without damaging the black coating on the aluminium window? Plenty of plastic scraper tools on Amazon claiming to be non-scratch, but it'd be useful to hear a method and a product someone has actually successfully used.

TIA.

That could just be the paint finish
or
Is it self coloured render ?

Self coloured render.

Ok
I queried as the overcoat on the sill looks thin

Travis Perkins are always a great source of advice. They sell render removers but suggest asking if they are ok to use on your sill

You could try softening the render with a vinegar solution

Use plastic scrappers to avoid scratching the sill.

Thank you for responding. Glad we came to same conclusion re plastic scrapers plus vinegar.

I’ll try TP too. Thanks again.

I would just paint it black so it isn't noticeable if it were me. Then you don't risk damaging the windows.

Thanks @Geneticsbunny: that’s what a friend also recommended.

The other thing you could try is contacting strippers of Sudbury. They are very helpful and sell a huge range of products for stripping stuff off of other stuff. I think they can send samples out too.

Thanks for that @Geneticsbunny!

That would drive me nuts too. I'd probably just buy zinsser allcoat paint.

I know @BoarBrush. It was a whole home renovation and we stripped right back to the brick, moved the staircase, loads of structural work. So there was lots to focus on and this somehow slipped through my usual perfectionist net.

The rest of the finish is immaculate but an acquaintance pointed it out while visiting on Saturday and now I can’t unsee it. 🫣