How do you treat pine knots before painting?

Roughen the surface of the existing paint with some 120-grit sand paper used by hand, daub a coat of stain blocking primer on the knots, add another coat in the same way, then use 100% latex paint as usual on top. This even works over old oil paints if you use the right kind of primer.Click to see full answer. Regarding this, how do you treat wood knots before painting? Priming Bare Wood If you are deciding to paint bare wood, you should seal all knots (spot prime) with a shellac based primer. Shellac based primers are great for sealing wood knots and sap streaks. They do carry a pungent odour, but dry very quickly and will not let the knot bleed through the top (finish) coat. why do knots in wood come through paint? A: While it’s very common for knots to show through paint after application, this might not be a problem in your case. The reason is because the wood is so old. Knots show through paint when resins seep to the surface and cause discolouration, but the resin might be completely oxidized by now. Secondly, how soon can you paint over knotting solution? Can be over coated after 30 minutes. Woodworks Knotting Solution will cover approximately 10sqm per litre, dependingon the nature and porostiy of the timber. Shake well before use. Using a brush or lint free cloth, apply a liberal coat and leave to dry.How do you seal knots in wood? Polyprep 205-112 Sealant Scrape away excess resin. Heat knots with heat gun and again scrape away excess resin. If knots are tacky, wash surface with turpentine or Polyprep 875-104 thinner. Sand rough spots and vacuum up dust. Apply thin, even coat of sealer. Let sealer dry completely (1 hour).