Hi, My boats is scumbled internally, some areas need to be made good, (it's 25 years old), I have tried scumbling, takes a while, do lots of practice sheets (yes. sheets 3' x 4'), take care with the undercoat and apply the scumble finish, then apply about 4 coats of good quality varnish. The 'Masters' comments about knot holes is brilliant. - Having followed this procedure on the test pieces ----------start work on the main piece. I saw a back cabin that had been decorated by the 'main man', it was work of art - the owner may well post it. KK! wake up...........my attempt was pleasing, a back slide, not seen by many, but the varnish is lifting after 4 years, where the wind whistles under a gap.