[wood painting] To oil or not to oil

[sundaydiyer]

Hello,
I spent some time (highly understated) recently stripping old paint from staircases and now it's time to paint it.

Since I know now how consuming is paint stripping I would rather not repeat the process so my question is simple:

Would you recommend water based undercoat + water based paint (don't care too much about shine but given it's an old wood the are is not completely flat? Attaching a photo to give a better idea.

Thanks for advice

 

[gc1967]

If you were going to use water based undercoat and topcoat, you would have to put an adhesion primer or knotting solution on all the knotts or they will just burn through the water based paint.

 

[sundaydiyer]

@gc1967 thanks for reply; i was thinking about using 2in1 primer and undercoat and do two coats (i bought the one attached to this message). Do you think I still need knotting solution given it's an old wood and probably knots have been treated at some point in the past.

 

[gc1967]

That is water based primer undercoat, I have been a painter and decorator for 33 years and if I was doing it for the sake of say 1/2 hours I would knott all the knotts, because you dont want to do all that painting and in a few months time seeing brown marks burning through the paint, better to be safe than sorry, but this is just what I would do and my opinion.
Best of luck with your project

 

[sundaydiyer]

Thanks a lot.

 

[gc1967]

Thanks a lot.

No Problem

 

[opps]

I am not a fan of waterbased wood finishes, however I do use Leyland Trade acrylic primer (waterbased) for the simple reason that it is the only one that I have used which is easy to sand flat (using 180 grit silicone carbide paper). As an added bonus, it is incredibly cheap- about £20 for 5L.

That said, if I were asked to use a waterbased top coat, I would apply an oil based undercoat first.

Waterbased primers do little to reduce the level of suction- that is to say that don't "weterproof" the surface in the same way that an oil based primer or undercoat would. When you apply the first coat of waterbased eggshell/satinwood/gloss over waterbased primer the paint soaks in really quickly and doesn't flow very well, often resulting in very heavy tramlines (brushmarks).

The (primary) downside to using an oil based base coat is that you need to wait longer before you can apply the waterbased finish coats. If you do it too soon you may end up with fisheyes- pools where the paint pulls itself away from the surface, effectively leaving little craters.