The three most common ways to get finish onto wood are to spray; use a handheld applicator such as a brush, paint pad or roller; or wipe. In this segment, I’ll focus on wiping — the easiest and most foolproof method.
Danish oil, teak oil and many wipe-on oil-based gel and liquid polyurethanes are sold as wipe-on finishes, but that’s really a misnomer. It would be more accurate to call them wipe-off coatings, because the key to good results is not how you put them on the wood, but the fact that you wipe all the excess finish off.
Take Danish oil, for example. You flood it on liberally, let it soak in a bit, then wipe off everything that was not absorbed by the wood. You can do the same with wipe-on liquid or gel polyurethane, or for that matter, with any oil-based liquid varnish or polyurethane, whether labeled “wipe-on” or not. My favorite method is to dip a gray nylon abrasive pad into the finish, scrub it onto the surface making sure it gets down into the pores, then wipe it off evenly with blue paper shop towels. Do that once a day until you have as many coats as you need.
Once wiped, a very thin coating is left that dries fast and is too thin to pick up airborne dust or show brush and rag marks. Because oils cling so well and spread so thin, oil-based finishes leave a thin film each time you wipe them on and off, even after the wood is well sealed. That allows you to build multiple thin coats, considered ideal in the world of finishing, with very little effort and virtually guaranteed, perfect results.