Painting pine with knots

[robson]

I must have used a crapped out shellac when I sealed the knots prior to painting pine. Can I get away with painting over it with a stain hider or do I need to sand out the knots and reseal with shellac?

[m Ransley]

I dont know how shellac gets "crapped out" to not seal because you use alcohol to thin it, maybe the wood is a bit green and an active knot

[Edwin Pawlowski]

I think it fails to harden properly after a while. Mixed shellac has a shelf life of about 6 months, but he canned stuff is longer.

To answer the OP, I'd wipe the wood down with alcohol first, then apply the sealer, such as Kilz.

[Dan_Musicant]

1. First coat: Very thinned down shellac, a 1/2 lb. cut.

1. Coat with boiled linseed oil and wipe dry with rags after a few minutes (e.g. 15 minutes). Some discarded socks are very good for this.

2. Let dry - depends on weather, anywhere from 4 days to 2 weeks.

1. Two coats of shellac, followed by two applications of furniture wax rubbed in with very fine steel wool.

After almost two years this has been very stable, no bleed through.

[nospambob]