Furniture, Wood and Cabinetry Finishing - what is the best external oak oil

I am about to buy some white oak bi-folding doors for external use. The company I am buying from will supply the oak doors with a tung oil finish with only one years guarantee. I am worried that the doors in time will split/warp etc.... how often do i need to reapply the oil, will it actually fully protect the wood from water and sun etc.... what is the best product on the market, I don't want to spend all this money just for the doors to disfigure and not work in the future!!

Toby

Long term, only an opaque finish (paint) will hold up to constant sun exposure. However, if you want to try a clear finish, a marine spar varnish, such as McCloskey Man O'War Spar Marine Varnish, would be your best bet. It contains UV inhibitors which allow for prolonged sun exposure. You'll probably need to sand & refinish every few years. Good luck