gloss sanding

Hello In the past whenever I've painted with gloss paint it has only needed one coat. However I'm about to paint a bookcase with a dark gloss and I wondered what to do if it needs a second coat. Do you apply the second coat as soon as the first coat has dried and do you lightly sand the first...

A few days ago we glossed some brand new wood architraves (after knotting, priming and undercoating) with Dulux non-drip. A screw up (not ours!) meant that some protective plastic sheeting ended up stuck fast on one side, not picked up until 12 hours later. When removed it left a crazed look to...