if outside gloss is no longer glossy, what kind of prep?

[mattyfoo]

as subject suggests, i have gloss paint outside (windows, soffits, etc) that is no longer glossy as it's been exposed long enough. Does this still need sanding? I'd thought I'd scrape any loose paint (really not much loose). Is a wire brush a useful thing? Can I get away with just a washing down with sugar soap? Also, what's the norm here, an undercoat and two coats of gloss? Just one coat of gloss? Would a primer rather than undercoat help ensure good adhesion? Many thanks

 

[Lyngarth]

Lightly rub down and clean off with sugar soap and you only need to prime any bare areas.

I use one undercoat and one gloss (oil based trade paint ) but I know some people use two gloss.

 

[mattyfoo]

sorry, when you say lightly rub down -- is that with 80 grit sandpaper then? Because of the details around the soffits, a wire brush would be easiest -- is this okay? I know that the point of rubbing down is to provide a key, but the surfaces have thoroughly lost their gloss, the appearance is either dull and almost sandy or slightly crazed but still sound. To me, it really looks like gloss paint would stick well, but I'm just a DIYer so I don't know. I'd like to make the right decision here, but the work involved in sanding everything down is huge, so if not entirely necessary, it'd be great to skip it... Thanks

 

[sparkwright]

Old gloss paint that has lost it's shine still needs rubbing down properly, as new paint will peel off quite rapidly.

Don't 'miss' areas when sanding, new paint will flake.

 

[mattyfoo]

so is a scrubbing with a wire brush an option or does it have to be sanding? thanks again...

 

[sparkwright]

Personally I would favour sanding as you will get a smoother, more even surface, and are less likely to 'miss' bits.

Sounds a pain - best advice is just do it and do it quickly.
Try a sanding block on a pole for large areas if you think it will be easier.

Prime all bare wood.

 

[sparkwright]

If the existing paint is generally sound, after preparation prime bare bits.
One under coat followed by one gloss coat should be ok, unless you are covering a particularly dark colour where two under coats will be needed.

 

[Robbie uk]

Sparkwright is spot on, dont bother with the sugar soap, shouldnt be needed outside. One undercoat and one gloss will do no probs. No need for primer on previously painted wood, only on the raw bits. Dont think a wire brush will of much use really.