Window Sills

[NewhouseOldhouse]

Hi

My window sills have been painted white by previous owner but are now very rough looking as in paint flaking off and very grubby.

What best way to take paint off and best way to paint sills white again?

Thanks

 

[Odds]

A good paint remover, like Nitromors, and several grades of sandpaper usually do the trick. A quality gloss paint to finish.

 

[NewhouseOldhouse]

A good paint remover, like Nitromors, and several grades of sandpaper usually do the trick. A quality gloss paint to finish.

Do I need an undercoat or just gloss?

 

[Odds]

You can use a one-coat gloss or go nuts and prime, u/coat then gloss over the whole shebang. Your call.

 

[Wayners]

Tungsten scraper and sanding to remove paint.
2+ coats of coverstain and de nib with 320 grade between coats.
Masking all around and paint again.

Flaky paint is a common problem as diy people lash on any of old paint with no preparation or undercoat.
It's a headache on large jobs and sometimes easier to replace woodwork

 

[opps]

Photos would be really useful.

You may need to remove the paint back to the wood, you my not need to remove all of the paint. A photo will help us offer better advice.

 

[NewhouseOldhouse]

Oh sh1t sorry I mean external sills, inside are PVC

 

[Odds]

 

[Wayners]

Wood outside? Advise still stands.
If stone chemical strip

 

[NewhouseOldhouse]

Stone/cement external sills

 

[DiyNutJob]

Sand paper works on everything. I normally use 40 grit (except for headlight lens) and go higher if too rough. I would not strip. Anything that stuck on well is worth preserving. They offer great protection.

 

[opps]

Are they concrete or sandstone sills?

If sandstone, it may be advisable to check the integrity of the existing finish (read:surface of the sill). I am currently working on victorian sills that had been skimmed with something like Jetcem (a rapid setting cement product). In time it had blown. I "chiselled" away the Jetcem, and noticed that the sandstone was very soft. I scraped the loose stuff away and applied SBR to seal it. On some of the sills I had to apply a layer of cement and plastering sand to get a decent fall for the water to run off.

If it is a concrete sill that has been cast in situ by a regular builder, you may well see air bubbles in the existing finish. The sill will be much harder than a sandstone one, meaning that any paint cracking is (possibly) down to poor application/paint choice, and not down to the sill degrading.

Again, photos will help.