Originally Posted by rogerg
Yeap, got that, what I was meaning is if I'm going to have to buy undercoat, buying varnish instead is probably similar cost. As opposed to doing neither and just using the spare interior paint I have at home for free
I am a bit shocked Gary didn't pick up on the fact that you said "interior" paint. Although his description of the undercoat is adequate, unfortunatley the under coat is not the main reason for painting defects. It is the top coat used. No undercoat will fix, the wrong topcoat.
I would be more concerned about the paint you have left over...
I would assume it is water based wall paint. Do not use that.
You need to use an oil or water based enamel for hard wearing surfaces.
Water based acrylic will just peel off, when it touches/taps something..
Dulux Aqua-enamel would be suitable, or a good old oil based is best.
Although an undercoat is recommended, it is not necessary. Paint bonds perfectly well with almost all timber / metal / masonary surfaces, given proper preparation. It needs something to "bite" onto and a dust / grease free surface, to not peel away from. An undercoat just means you don't need to prep so much, still needs to be dust free though.
I would varnish it. Cheaper and looks better IMHO
(I also work in paints.