On 22/10/2012 21:39, polygonum wrote:
Have been doing a bit of interior painting recently - where I have been
using Joncryl primer/undercoat and Johnstone's acrylic sheen. Because I
have been switching between the two, I have repeatedly washed the brush
out after doing one or two door sides. (With oil-based I'd have used two
brushes and not cleaned fully till the end. But it is so easy to wash
out the water-based...)

The washing out and thereby not allowing any significant accumulation of
drying paint to occur made life so much nicer. Previous usage of
water-based I have tended to keep going, going, going and getting a
slowly-drying ridge of paint towards the top of the brush - but never
again.

And the paint finish has been as good as any I have ever achieved. I
like this new era of water-based...


The problems with water based have been a) retarding the drying to allow
the paint to form a uniform film and b) imparting toughness into a film
that will perform at low temperatures. I don't think there will ever be
a good gloss, but undercoat and satin seem to work well enough. Not sure
about high traffic skirting etc though.
There are superb acrylic finishes (these days on most cars I would
think) but they need a precisely controlled temperature during
application and drying. Not easy given how the temperature drops during
spraying. Maybe they dip cars now?