After wire brushing two old galvanised steel garage doors I am left
with a very uneven surface from where the (thick) paint has come away.
Most of the paint is still intact and I think stripping it all would
be a huge effort. The edges of bare patches don't seem to want to
'feather' - the paint is brittle. Any way to get a reasonably flat
surface for a finish coat? I started filling in with undercoat but the
bare patches are way below the rest and it looks a bit like the
surface of the moon. Is there any kind of filler I could use?
Thanks for any advice.