painting exterior doors

Wig

Need a bit of advice, I'm going to paint exterior wood doors probably with quick dry dulux weathershield blue, I think they only sell it in max 2.5 litre tins, would like to buy a 5 litre tin for better value but seems not available.
Seems to be about £28 per tin in shops.

Anyway, doors not painted for 15 years, current paint is sun bleached and cracking open in places

What would you do? how far to sand back? undercoat needed?
Shall I use a modern man made bristle brushes? 2 inch, 1 inch and a 0.5 inch brush set?

Would a cheaper paint do? Actually now I remember Sandtex also does a blue gloss a little bit cheaper. but what about cheaper non brand stuff? B&Q Fortress gloss does not have a blue in the range. Any others?

Thanks

nickj_2

if the existing paint is brittle and you want to do a pucker job then i would suggest removing the paint .
depending on the paint you use will determine the process required , dulux needs a preservative primer , 2 u/c's and a top coat .
if you stick to the well known brands you won't go far wrong , although water based paints imo are a good bet for woodwork that gets a lot of sun , also i persobnally would go for a lighter shade if it does get the full sun

Wig

And if I'm not removing all the paint, but there are a few areas cracked open possibly down to the wood, which I will locally sand very well....do I under coat just those areas or undercoat across all the old blue paint aswell?

jcb208

Scrape back loose areas sand ,then spot prime.If your using the water based exterior gloss it is still best to undercoat.2.5 Ltrs will be more then enough for 2 doors even If they are garage doors

theGrinch

filler and sand will help get a smooth look