silly question about knotting

[WoodMangler]

A silly question really, but one I've never seen answered anywhere - when making things in 'ordinary' whitewood, should the knotting be applied before sanding, or after ?

 

[beech1948]

After.

Knotting by the way is usually a mix of shellac...so if you have any try to give it one or two coats of shellac first.

Al

 

[Fatboy11]

Rub the knotting back after with 400 grit lightly and tack before finishing too.

 

[adzeman]

You do it after sanding not only on new wood but when external decorating and you have stripped the paint down to bare wood. Its done to seal the knots from bleeding which they do exstensivly when exposed to direct sunlight or any sunlight.

1. strip timber to original surface
2. sand
3. Knot, prime and stop (fill any holes and indentations)
4. apply two undercoats
5. apply gloss finish.
Lightly sand between all coats.

 

[WoodMangler]

Thank you all very much for the advice.

 

[Dibs-h]

TBH - depends on what you are making and the orientation of the knots, i.e. if the knotted surface is horizontal or vertical and if it is exposed to sunlight.

A vertical surface exposed to sunlight - I doubt personally whether the solution & umpteen undercoats & topcoats would achieve much in the long run. I learnt that the hard way - I would either route out the knot to a depth that would allow a larger sized thin'ish piece of timber to be let in or filled with an epoxy based filler. This was, I know there would never be any issues going forward.

My 2p worth

Dibs