Poly has a place in finishing...
Every coating has pros and cons, weakness and strenghts, selecting the right coating depends on the usage of each piece.
Polyurethane, needs no sealer, thin the first two coats 50 % of Mineral or White Spirits.
If Shellac is used to prevent fisheyes, it must be dewaxed Shellac, if not there will be poor adhesion, and it must be sanded back, as Shellac is the softer coating.
It is suggested, to stay with the poly all the way.
Drying Oils do not dissolve...
[QUOTE=GAJD04;596636]Hi, I think the easiest way is to remove the danish oil with white spirit (not turpentine)
GAJD04,
White Spirits or Turpentine will not remove Danish Oil, because, DO is a reactive coating and reactive coatings will not dissolve.
Skew,
Its very easy to tell if its true Tung Oil, it must say, 100% Pure Tung Oil, this means it is unadulterated, nothing is added. They can use the term Tung Oil, but they cannot add 100% Tung Oil.
MacS