Undercoat - do I need to rub down?

BobRobUK

I am in the process of painting the exterior of my windows. I have lightly rubbed down the sound existing paint and applied the undercoat.
Do I now have to rub this down to provide a "key" or will the matt surface of the undercoat suffice?

Thanks in advance
Rob

Lord_Gardener

I always give a light sand down - even for under coat - and find that it gives a better finnish. I heard this tip from a P & D a few years ago who had been in the game for ~ 50 years! Also said to paint 2 coats of thin top coat rather than 1 thick coat (get better longer lasting finish) and of course lightly sand down in between!!

BobRobUK

I was hoping I would not have to sand it down again, fed up with it!
Already it has taken me 4 full days to get to this stage, how on earth do the proffesionals do it so quickly ?
Maybe they give it a quick scratch over, ensuring they will have to come back a couple of years later when it is peeling off.

Rob