Varnish on Linseed oil

I built a pair of paddles, and am finishing them with linseed oil. Can I seal add a coat of varnish on top of linseed oil?

 

Yes, but only after the linseed oil is dry.
If it was raw linseed oil, it takes quite a long time (how long depends on temperature and humidity). If it had artificial driers added, it will be much faster.

Marine spar varnish is compatible with linseed oil because the main ingredient is linseed oil. This helps keep the dry/hardened finish very slightly flexible, so it doesn't chip or flake. The same is not true of urethane-based finished.

Be sure to use a formulation that includes UV protectant -which all marine spar varnishes will contain in varying amounts.

 

You can speed up the linseed oil cure by blending in turpentine and mineral spirits. As Rob notes, artificial driers help it to cure faster. A good starting point is a 60/25/15 blend.

 

Sorry for the trivia, but what up with the last 10% in the recipe ? I could see maybe, some Everclear.

 

Ha....duly noted and corrected. I mastered diffeq in spite of my inability to add. We may have discovered why one of the stems I just made is too short.
Not a big fan of the Everclear and yet, there is a bottle on the shelf in my shop....