Best stain blocker?

[womble69]

Afer the bad winter, I'm now getting around to redecorating where the water (11 burst pipes!) came through the ceiling.

Minor ceiling stains have been killed with Everbuild aerosol stain blocker, but there's a monster stain on the kitchen ceiling that it can't cope with - it keeps showing through.

Any recommendations, tips?

 

[dcdec]

I always use the shellac based zinsser bin, a couple of coats should do the job and be prepared to sling your roller sleeve!