old painted surface do I need to use the primer?

happyhero

Hi I am painting some timber cladding on the front of my house. While I was preparing it a few bits of old paint came off exposing the timber but on the whole 80/90% of the old paint is sound, just tired looking.

I bought some Sikkens Rubbol XD Gloss and some of the recommended primer to go with it, Sikkens Rubbol Primer Plus. Where should I use the primer i.e. should I prime the lot as it will give a better job or do I just prime the few bare bits?

I was thinking perhaps the proper prime will give a better base for the top coat to bind to rather than some old unknown paint but at the same time I wondered if it was a bit silly priming an already painted surface.

Any advice or help would be appreciated.

McKneff

You really would be better getting off as much of the old paint as possible, all of it if you can. If some of it is coming off, the rest will come off eventually so will bring the new paint off.

Preparation is everything for a better finish and a long life.