Painting windows

[jane99]

We've had timber windows installed, and they were primed, but a friend has said they need to be painted, or at least undercoated quickly as the wood colour is seeping through the primer. Would appreciate people's opinions on water versus oil based paints, and undercoating separately (which appeals because we're no where near deciding what colour we want to paint the house). Thanks, Jane

[GeoffS]

Primer is not a finish and must be covered to protect the timber.
Acrylic paint lasts a lot longer (up to 10 years) than oil based.
If the windows open acrylic paint can be a problem on contacting surfaces. Unlike oil paint it may tend to stick every time the window is closed and this may result in the paint being pulled off.
If the primer is oil based you must not put acrylic over it until it has had some weeks (preferably of hot weather) to 'cure'. This always applies to putting acrylic over any oil based paint.
I'm not a painter - have learnt or at least confirmed all the above from practical experience!
There is no perfect solution. It is a compromise whatever you do.
Cheers

[Theva]

jane99,

I would not worry about primer getting discoloured. You have to overcoart it with paint anyway.

As per previous post, you can paint with a system of your choice when ready. Any exterior grade paint will do; my choice will be a low sheen acrylic like Wattyl Solagard two coats minimum. It does not require un undercoat.

Regards,

Theva

[MarkV]

Personally I wouldn't touch acrylic for windows or doors it just doesn't seem to cut the mustard IMHO. I would use an oil based undercoat then an oil topcoat x 2. Acrylic will tend to stick more and has a nasty habit of just coming off in contact spots oil based just seems to rub and wear in. Most importantly you should allow plenty of time to dry between coats , in my experience 2 days of warmer weather, and sand lightly between coats to keep everything nice and neat i.e no lumpy bits to catch on the frames. An oil based undercoat will last for many months uncoated to allow you to decide on your colour.

[jane99]

I spoke to the person who made the windows - the sill, where the colour is leaching, is made from Mirboo which often leaches tanin/stain, and while they used an oil based primer the underside of the sill isn't primed which I think is why it's started to leach. The rest of the windows are ok, so I think I'll just do the sills on these windows. When I went to the local paint shop they recommended Zinsser BI, which is a Shellac Base Primer and Sealer. After reading your posts and looking at the Zinsser brochure they do have an oil based product called Cover Stain, but I seem to remember the bloke saying I could use oil based paint with the Shellac based product. Has anyone used these products/have an opinion?

[GeoffS]

Jane
Have a good look at the amount of future work you may be giving yourself.
From what you have said in your last post you intend to maintain a timber look finish and do not intend to actually paint the windows.
My favourite paint shop (which I put a lot of faith in) will not guarantee any clear finish to last longer than 1 year. They don't care what the tin says!!
Now this is in Mildura, a hot dry climate, but I don't believe anywhere in Australia is going to be a lot better. Paint that gets direct sun on it has a limited life (acrylic - up to 10 years, good oil based - up to 5 years) but it is a LOT better than any clear finish.
If you don't re-do the clear finish regularly ( before it cracks and crazes) you have to clean it right back and start again. In the meantime the timber is suffering.
I recently used all these arguments on my sister who has a 6 year old mud brick home in which the clear finished windows were disintegrating. She finally did her own research as well and decided on oil paint (for the sticking reasons) on the sashes which get some protection from the fly wire screens and acrylic on the architraves etc.
Long post for me but I think I've given you all my opinions on the matter!!!!
Cheers and good luck

[nine-to-fiver]

jane99,

Our door supplier recomended that for a timber finish seek out a good marine finish. Thay cover all there doors with it for display and swear by it.
Just a thought.

Regards,

Scott.