How to Apply Linseed Oil to Polyurethane Finish

Check that the polyurethane finish has not been heated and is not tacky to the touch.

Roll a soft, clean cotton cloth into a pad that will fit into your fist. Remove any loose threads or pilling from the pad.

Soak the bottom part of the pad in boiled linseed oil. Saturate pad with linseed oil but don't let it drip.

Apply the pad to the wood surface, using a rocking motion of your hand and wrist. Apply more linseed oil to the pad, and stroke the wood surface until the entire surface has been polished with the boiled linseed oil. Let the linseed oil dry for 24 hours.

Repeat the entire application process four more times, letting the wood dry for 24 hours in between each boiled linseed oil application. Polish the wood surface to a high shine with a dry, clean cotton cloth.