Painting exterior window sills

lauraland

Hi there!

I'm planning to paint my external window sills and I'm a bit confused as to what to use.

Most of the sills are concrete. I have been stripping all the old paint off, and have got most of it off, bar a few stubborn patches that actually seem to be engrained. I understand that I need to use masonry paint, but will I need to use a stabilising primer beforehand? Or will a diluted mist coat suffice? I really don't want to be doing this job again next year due to flaking paint!


I do have one problem sill were lots of layers of old paint just wont budge, what do I do with this? Sand it down, then use a primer of some sort?

I really appreciate any advice :-)

Kiran

For your stubborn sill have you tried a heat gun. Work of warning don't heat one spot too much as it can cause the aggregate to explode in extreme circumstances. As long as you keep it moving this will work.

As for the paint, a pliolite based masonry paint works well and doesn't need stabilising solution. It does smell a bit but it is very hard wearing.

armchaireconomist

Just key the stubborn bits and slap some Sandtex masonry paint on. The "textured" one will hide the imperfections below. Smooth will look suspect unless you do a lot of prep.

lauraland

Thanks for the replies! I have used heat gun, paint stripper and a lot of elbow grease! Paint wont shift. If I just sand and slap on masonry paint will it stick ok? Read that water based will flake off oil based, thats why I was confused whether I needed a primer or not.

armchaireconomist

I wouldn't worry too much, just sand it to a rough texture so paint can bed in and make sure surface is clean and dry. I've painted Sandtex over stubborn bright green (oil-based) windowsills and it's absolutely fine.

lauraland

Thank you - thats good to know and will save a bit of money and time!

armchaireconomist

FYI not sure how far you made it but pressure washers are great at removing flakey paint and grime.