Preparing external window cills

[Launchbury]

I'm preparing to paint my window frames. I've scraped off all the flaking paint from the window cill (outside), it's left me with the old paint rubbed down ready to paint, but there's lots of areas where the paint has come off completely leaving bare wood.

If I paint over everything it won't leave a nice smooth, constant finish. Do I have to fill the lows or keep scraping and get every bit of paint off?

Once I've done this, is it;

1 x acrylic primer
1 x oil undercoat
2 x gloss

Thank you.

 

[Crystalclear]

Found this on the net...

"... if you have sanded it all down and filled any bits that need doing then you are ready to start. First of all you will need to prime any bare bits, then give it 1 or 2 undercoats depending on how it covers followed by a topcoat ie gloss, eggshell. In between coats I would give it a very light sand with fine sandpaper to remove any little bits that may have found their way on to it and if you want a really bit free finish get a tack cloth and wipe that over it before putting on the finish coat. Make sure you use a decent paint brush as this can make all the difference. I always use Hamilton Perfection brushes myself, others on here would say to use Purdy. It depends on how much you want to spend on them. One final thing would be that if you think any of the surfaces are greasy or dirty then wash them off with Sugar Soap before putting any paint on as paint will not adhere properly to dirt of any kind."

 

[Chri5]

After scraper you need to sand with 80 grit. Then spot prime the bare wood, then undercoat the low areas rub back with 120 and see how the pre top coat finish looks.

If there's still lows add more undercoat, use a fine 2 part filler or decide a minor amount of blemish is acceptable.

When I scape, I tend to follow along with the heat gun. The absolute best way to avoid highs and lows between paint and no paint areas will always be to take the lot back to bare.