I am painting my front door with a high gloss paint and so far I have applied 2 coats of undercoat and one coat of the gloss (sanding between coats). The colour looks a little thin in places so it will need another coat of the gloss paint. Should I sand again before applying the second coat of gloss?
In my humble opinion, NO. The most important job to get right was the first. Presuming the door was new I would have given it a good sanding, then applied a coat of wood primer giving it plenty of time to dry into the wood. If the sanding was properly done at the outset, there would be no need for more. Then apply 2 coats of good gloss paint with a good brush. Stand back and admire.
Sanding between gloss coats is to give the paint something to grip on to, rather than to smooth any bumps. I HATE sanding but it is a necessary evil. As callybags says, you just have to give it a light sanding but you don't want to skip it, put on a few brush-strokes and then realise you should have done it (as has happened to me).
If sanding gloss to make it really smooth like glass use a really find sand paper.
Plus there is a sponge brush which can be used to paint gloss, I've used one before and it is hard to get right but it is spectacular when you do get it right.
There is also a clothe which can be used for applying oil based paint.
However for the vast majority of people I suggest keep using a brush.
In my humble opinion, NO. The most important job to get right was the first. Presuming the door was new I would have given it a good sanding, then applied a coat of wood primer giving it plenty of time to dry into the wood. If the sanding was properly done at the outset, there would be no need for more. Then apply 2 coats of good gloss paint with a good brush. Stand back and admire.
you need to sand between coats of gloss,also your semi right with the use of a "wood primer" on a new door,it needs to be an aluminium primer most importantly.