Painting south-facing window cills

[GMM]

Wrong time of year I know, but I want to do this as soon as it starts to warm up so best to be prepared.

The back of our 3 storey house faces south so, even in these less than tropical climes, it gets a lot of sun and (sometimes) heat. We have an array of sash windows, each with a stone cill on the outside. Much of the paintwork on the timber is holding up for the moment (with a few exceptions) but the cills are in a bad way, with curls of paint (multiple layers) flaking off. The cills at the front are nowhere near as bad. I presume the problem started with poor surface preparation on the first coat and/or there has been some incompatibility with subsequent layers.

Whatever the issue, I'll have to scrape the cills back to bare stone and start again. On the basis that the bare stuff being exposed to the elements for a bit shouldn't be a problem, I'll go through them in turn, then paint the lot in (hopefully) one go, ideally in the spring without the full force of the sun on the job as I'm painting.

So - what's the paint to use in this circumstance? I don't really want to spend a load of time on this only for it all to peel off again and I don't mind spending a bit to ensure the job's a good 'un in the long term. Although it's not such an pressing problem, any experience with painting wood in this position would be appreciated too as there are a few places that could use a lick.

Cheer chaps.

[stuart noble]

IME if you get back to bare wood and get some wood hardener (or Halfords polyester resin) into the grain, any old paint will last 20 years or so. Similarly, any pre-mixed filler in a tub skimmed on to the cills will prolong the life of the paint. Doesn't need to be classed as exterior either

[Dave Plowman (News)]

I'd use a decent stabilising solution first - Blue Circle do a decent one. If you really must paint stone.

[John Williamson]

On stone cills?

[John Williamson]

The problem with painting most stpone is that the paint seeps into the surface, so once you've done it, it's almost impossible to get back to a decent stone finish. It's the same problem as you get painting brickwork, once it's done, it's got to be kept painted forever.

[Huge]

IME, no matter how much time and effort you spend on preparation and money on materials, the paint fell off my south facing wooden windows in 2 or

3 years. Thank Ghod for uPVC.

[rowing]

[stuart noble]

Providing it's being used as a skim/seal, yes IME. These days all pre-mixed fillers seem to be the same lightweight microsphere formulation

[GMM]

Well, I don't much fancy my chances of restoring all of them to an unpainted finish and I guess there will be some filler etc added over the years. Stabilising solution sounds like a start....presumably it seals the surface to some extent.

[GMM]

I can only agree with the sentiment, although I don't think the uPVC option would suit this house very well. I might see if I can slip some over the trims around the roof (fascias etc) when I get up there in the summer though. I had uPVC windows in my last place (they suited the house) so I never had to do anything once they were in.

[Andy Burns]

Weird stuff, makes you think they've filled the shelf with empty tubs.