Tung oil is the easiest to apply of the finishes I offer. That’s why it’s the only one I designate as the Fix-It-Yourself finish for guitarists who own my guitars. It’s available only on necks, in two ultra-thin coats. The tung oil finish on a neck provides the ultimate in natural, grainy feel of the wood while at the same time providing protection against perspiration and oil.
The material is available at practically all hardware stores and builders’ box stores (Lowe’s, Home Depot, etc.). I apply it with a four-folded 2″ square pad made of old tee-shirt: just saturate the pad, squeeze out the excess gently and rub the pad on the neck. Overnight drying is all that’s needed.
You (the guitarist) can also use this application technique to clean off dirt and oil from the neck from time to time.