I have some cherry furniture to spray that has had a light coat of linseed oil rubbed on. The linseed oil has been drying for six days. Can I safely spray Kemvar cv on the linseed oil. The Kemvar is self-sealing so I have just been thinning it for my seal coat and not using vinyl sealer. Also, should I light sand the linseed oil?
From contributor J:
I am not familiar with the finish you plan to spray, however, do you know if the linseed oil is boiled linseed or raw linseed? Boiled linseed oil has metallic driers added to help speed up the drying process. In my work I allow it to dry for several days before applying a film finish and have never had a problem. If however you are dealing with raw linseed oil it will never completely dry and will seep to the surface in warm weather and can cause problems with film finishes.
I've had luck wiping the oiled areas with a solvent soaked cloth to both remove the surface oil and to perhaps (I'm not a chemist so folks who know more please chime in) add a bit of drying agent to the outer oil to keep the raw oil from migrating to the surface. I have not had very much opportunity to try to apply a film coating over raw linseed oil but the one case where I did it seems to be working, at least I've never heard from the client who asked me to refinish her lovingly oiled dining table.
If in doubt, use a catalyzed vinyl sealer for the first coat of finish. Not only will you overall finish be more resistant to damage from water/moisture, but you will ensure that the topcoats have good adhesion. Make sure the vinyl sealer is catalyzed so the second coat of CV doesn't wrinkle.