jal wrote:
We had some DG windows fitted in our extension about 17 years ago.
These have wooden frames, which match those in the main (1960s) house.
The frames are (presumably) pressure treated for sealing against rot
etc, but they're (naturally) wood coloured, so I've painted them white
since they were fitted (to match the rest of the house).

I find I have to repaint parts of the frames almost every year, often
needing to strip down to 'bare' wood,because the paint blisters up, off
the treated wood. This is worst at the front, which is south facing and
experiences the greatest temperature extremes.

Wasn't there some kind of ?micropore? paint invented some years ago
which claimed to penetrate wood and not require repainting until, like,
10 years or so?

Anyone have any experience / suggestions please?

Cheers
John

Does this happen with oil based paint or water based? What you might
need is something with a strong solvent to etch its way into whatever
the original coating was.
I think microporous was an 80s buzzword. Pile of crap IME.