Large, sticky patches on tung oiled floor

Q: We have mahogany hardwood floors in our sunken dining room and throughout most of our house in NJ. We built the house with radiant heat throughout and used a tung oil finish on these floors. We have been living in this house for almost seven years now. In the winter I keep the radiant heat on in the main part of the house, but usually not in the dining room and adjacent hallway, since the other zones seem to warm the house sufficiently. Suddenly, a few days ago I noticed these weird sticky patches on my dining room floor.

There is no odor. They are not wet. Just really sticky. Some are pretty large (about 1 1/2 feet in diameter), but most are about 6-8 inches in diameter. Some patches seem to have emerged from under the outer wall and some are near the inner walls of the house but do not touch the mouldings. The stuff is really sticky, like honey, and shiny. I can’t imagine what is causing this. After I noticed these patches I turned the heat on in there thinking maybe condensation is pushing up the tung oil and glue between the floorboards? We have a full basement and it is warm down there in the winter due to the radiant heat. Anyway, one more patch appeared yesterday after I had already turned the heat on. I am at a loss about what could be causing tung oil finish sticky patches. Please if you can help I would appreciate any guidance.

A: I spoke with a tech person at Lee Valley Tools regarding their pure tung oil finish. He indicated it simply would not work on a floor because it takes far too long, days to dry and would have to be repeated every few months. I suspect it is the tung oil finish. I might suggest you look into an oil finish that contains tung oil as one of it’s 5 main ingredients along with linseed oil. It is very easy to work with, has no adhesion issues and does build a film after a couple of coats. I think this could be the answer to your issues.