Sap and knots

[tomredsky]

I used to like timber for skirting and architrave but now that I've got to prime and fill it myself, I wished the chippy had bought MDF.
I've got pine sap running out of this door linning and there's a ton of knots in the skirting that I know will bleed through unless I get my prep right.
I've got some Ronseal knot block primer and undercoat. Any other advice that will give me a decent finish?

 

[Wayners]

Dig out bad knots or problem areas and you can use 2 pack wood filler.
Aluminium primer I used on my pine stairs as the knoting solution failed and its been fine.
Give the aluminium primer a few days to cure following spec then 2 coats of acrylic primer.
Aluminium primer is gray unfortunately.
That's the best.

Next best is a shellac paint like Zinsser BIN but it's not a sure thing

 

[tomredsky]

you can use 2 pack wood filler.

What's a two part filler?
I just ran the hoover over an knot hole I'd filled and the polyfiller got sucked away

 

[endecotp]

What's a two part filler?

It’s a filler where you mix two components together. One is a “hardener” that is a catalyst that starts the reaction that makes it solidify.

Example: “Everbuild 2-Part Wood Filler”.

 

[opps]

The sap can be removed with white spirit but I would recommend waiting a few days before painting. It is likely to weep for a while.

I had to hang doors for a mate a while ago. The new door stops were extremely resinous. So much so that a lot dripped on to the new laminate flooring that I had fitted.

I pulled a few of the worst knots out. The "shakes" continued to weep for another 4 or 5 days.

I hit the knots and shakes with the shellac based Zinsser BIN and then used 2 pack filler, then hit that with another coat of BIN before priming with acrylic primer and followed up with 2 coats of oil based eggshell. That was 2 years ago. I did warn him that no product is guaranteed to block knots forever. Seem to be OK thus far though.