I would like to pitch in here, with both my experiences and some questions. I restored, repaired and redecorated all the sash windows in my grade 2 listed house around 4 years ago. I got all the sahes removed and dipped so started from scratch with bare wood. It took about a month to dry them all out, using a sealed room with dehumidifiers running non stop....I was keen to use traditional materials etc and so went with linseed oil paints by Brouns. I have had mixed results - it goes on lovely for sure, however, I have an ongoing problem with mould and dirt accumulating on the flat surfaces of the cills and mouldings. And when you clean the windows, paint dilutes with the water and goes all over the glass. I had some areas also where possibly I was geting bleed through of the dipping chemicals and other areas just seemed to never dry at all! And this is 4 years in!
I am going over them again starting this summer and have decided to use Dulux weathershield gloss instead. I did a test run on the porch and front door last year and the paint looks perfect a year on, which is more than can be said for the 2 or 3 windows I had to do some minor repairs and redceorating using the linsdeed oil paint ay the same time. We are slowly working round the house going over with weathershield Oil based. I notice no one who responded in the thread mentions using this at all? Just wondered why that may be? I found it very nice to use and very durable so far........
Currently I am also making some replacement sash windows for our neighbour, using sapele. I planned on using the same weathershield paint, but she wants me to use Farrow and Ball exterior paint. It is water based and I really dont like it so far, it seems very thin and I am dubious about it longevity......any users got any experience of this system here?
Because of my job and teh neighbours, I have been looking into the various options for paint and did come across a very complimentary long term test on YouTube, of the Treatex classic colour - this is also water based, but flexible and seemed good....again, any one used it?