After finishing wood with Linseed oil finish, can I coat it with Polyurethane finish?

Question

Does linseed oil or oil base finishes react to Polyurethane? And if it doesn't, will the polyurethane chip from the wood or wont adhere?

Answer 1

Let it dry completely, than sand it with a fine sandpaper, than clean off the dust. Now apply the Polyurathene. It is important that the surface is very dry.

"Polyurethane may also be applied over a straight oil finish, but because of the relatively slow curing time of oils and the emission of certain chemical byproducts, care must be taken that the oils are sufficiently cured to accept the polyurethane."

Answer 2

Of course you can, assuming the "polyurethane" is an oil-based version.  There are many finishes that are simply (boiled) linseed oil and varnish blended together in a wide variety of proportions (see link).  

If you have used BLO, it should be mostly cured in about a week.   Remember that your linseed oil finish should not have any film thickness built up -- it's designed to be in the wood, not on the wood.

I have a professional friend whose favorite finish on some woods is BLO, dry time, garnet shellac, then alkyd varnish.

Answer 3

NO.

You cannot put anything on top of linseed oil but linseed oil or paste wax. Nothing else will adhere.