Do I need undercoat?

[Boto]

I have recently had some new internal doors which are ?painted? whitish, don't know if it is paint on them, they were bought that colour. Do I need to use undercoat before the top coat? Thanks a lot.

[tonyav]

The Whitish stuff is primer, use a good one coat topcoat and they will be fine.

[bookbinder]

It would be the safest option to use undercoat first. I once tried to (lightly) sand down some gloss-painted internal doors for a relative, but they had not been undercoated before being glossed, and the paint simply fell off in sheets when I put the sander on them.

[tonyav]

bookbinder, yes I can imagine that happening if they were a smooth finish door but not if they are a grained finish. The op hasn't said what finish the doors are.

[bookbinder]

I agree, tonyav. If the op uses Dulux Once, that should be OK.

[Boto]

They are a grained finish.

[tonyav]

Should be ok then Boto.

[carrust]

Don't use Dulux Once or any other coat in one finishes. Undercoat & gloss the doors in Dulux trade paint....It'll last longer, as the one-coat systems dry 'soft'.

[heathfield]

If the grained finish is due to the doors being made from moulded MDF, try a tiny area first to make sure the paint will take. I had all sorts of bother trying to apply paint to such a new door. Goodness knows what the surfaces on these doors are coated with.