Not reliably. Pine knots bleed resin and tannins through paint, often as yellow or brown rings. The bleed can appear days, weeks or months after you have painted. Seal the knots with shellac, prime the whole piece, and then paint. Chalk paint is not an exception to this, even though some brands say it needs no priming.
Why pine bleeds
Pine contains resin, and knots hold more of it. Water-based paint softens and reactivates that resin, so stains can rise through a coat that looked dry. Old pine is not necessarily safe either: knots can still bleed when a water-based paint reactivates them. Water-based primers usually do not block this bleed, so use a shellac-based product for knots.
Identify the finish
Old orange or yellow pine usually has varnish, shellac or wax on it. Check which one before you start:
- Varnish: a hard, glossy film. Clean it and scuff-sand it with 180 to 220 grit before priming.
- Shellac: a thin, amber-coloured film that softens in denatured alcohol.
- Wax: a soft finish that feels greasy and smears. It must come off before anything else.
Remove wax first
Waxed pine needs the wax removed with white spirit or mineral spirits and an abrasive pad. Sanding alone leaves residue in the grain, and paint will not bond over it. Clean again after removing the wax, and let the wood dry before you go on. How to clean old wood furniture before refinishing explains the cleaning order.
Seal the knots
Use a shellac-based primer such as Zinsser B-I-N, or a shellac knotting solution, on every knot. Fresh sap beads on knots; scrape it off, then wipe the area with white spirit or mineral spirits before you seal. Apply two coats over each knot, and feather the coat a little beyond the edge of the knot so it blends into the wood.
Prime the whole piece
After the knots are sealed, prime the whole piece with shellac or oil-based primer, which work best on pine. Then paint with latex or acrylic. Pine is soft and dents easily, so fill any dents and gaps with wood filler and sand them flush. Shallow dents can sometimes be steamed out instead.
Chalk paint on pine
Chalk-style paint can go over pine that has been cleaned and sanded, and it covers pale colours well. It does not stop knot bleed, though. The brand’s own pine guide says you can paint over varnished pine without sanding or priming, and that claim is about adhesion and coverage. Knots still need sealing with shellac before you paint, whatever the paint. For more on painting over varnish, see chalk paint over varnished wood.
Sand gently
Pine dents easily, so sand with light pressure. Start at 120 grit on bare or damaged areas, and move to 180 to 220 grit before priming. Going finer than about 220 grit before primer can reduce adhesion. After primer, sand lightly with 220 to 320 grit, because water-based paint raises the grain of pine.
Safety
- Shellac and solvent primers are flammable. Ventilate well and keep flames away.
- Test old painted pine for lead before you sand. In the US, paint applied before 1978 may contain lead.
- Wear a dust mask when you sand.
For the wider decision on bare wood, see can I paint directly on wood without primer.