Repainting skirting boards question

[t3rm3y]

Hello. When we purchased our house(first house) the bathroom skirting were new. I painted them (no primer, just two coats of paints) bit now I'm noticing knots in the wood showing through.
If I wanted to repaint or cover these would I sand back slightly, then paint a couple more coats over. Or sand back and prime first this time and the paint?

 

[geraldthehamster]

Knots need to be sealed with knotting solution (shellac), to prevent bleeding through paint

 

[JohnD]

Or you can use Aluminium Wood Primer, which I prefer.

 

[opps]

Or you can use Aluminium Wood Primer, which I prefer.

I too normally go for a shellac based paint. Aluminium Wood Primer is a good call but may require more coats of undercoat to obliterate the Aluminium colour.

I have seen persistent knots bleed through shellac, in some cases I have had to pull the knots out, have you experienced the same with the Aluminium Wood Primer? TBH it is years since I used Aluminium Wood Primer.

 

[JohnD]

not that I recall. It is very durable and I used to use it for windows and especially wooden sills. I would automatically use it on exterior glossed woodwork, but I haven't got any now. Only stained or oiled.

 

[t3rm3y]

Thanks for responses. So if I were to purchase one of these items would I still need to run down the painted skirting boards or simply paint directly on top? And I assume I then need my satin wood white paint or whatever on top of this ?

 

[Nige F]

Try Zinsser B I N - it's shellac based and white - but apply with a cheap brush and throw away because it's not easy/worth cleaning out. So rub down, spot prime the knots showing through, then carry on.

 

[opps]

Try Zinsser B I N - it's shellac based and white - but apply with a cheap brush and throw away because it's not easy/worth cleaning out.

I used to use cheap throw away brushes until I discovered that household ammonia completely breaks it down. I just pour a little ammonia into a suitably sized container and swish the brush around for a moment or two. If the brush had started going hard, I leave it in the ammonia overnight. By morning the ammonia has evaporated off and I am left with the brush sitting in water with white dust in the bottom. I then rinse the brush under a tap and pour the waste liquid from the container down the sink. Once the sink has been rinsed no residue remains.

I wish cleaning oil based brushes was so straight forward.