Applying Clear Finishes
This is becoming an increasingly popular choice because of its quick drying time, resistance to moisture, low toxicity and easy clean-up and disposal.
It's recommended for floors, woodwork, furniture and tabletops, and it's available in a variety of sheens: gloss, semi-gloss and satin.
One drawback is that being water-based it can raise the wood grain which then requires some extra sanding to smooth out.
Like other oil-based products, this is losing favor but is still easier to smooth out than water-based polyurethanes.
It forms a hard, durable finish and it's also available in gloss, semi-gloss and satin finishes.
The disadvantages are a slow drying time, closely regulated disposal and higher toxicity.
Resin Oil or Tung Oil Finish:
This finish is not as durable as polyurethane, but it's better for producing a natural, hand-rubbed finish that penetrates the wood.
It's recommended for highly detailed wood pieces, antiques and wood surfaces with attractive grain patterns.
Both water-based and oil-based polyurethanes can be spread with bristle or foam brushes, and on larger surfaces like floors you can use a painting pad with an extension pole.
As it's spread out, the polyurethane will often show brush marks but those usually disappear as it levels itself out before drying.
Don't over-brush the surface trying to smooth out the brush marks yourself. That introduces air bubbles which can dry in place and require extra sanding to remove, especially with the quick-drying water-based products.
And don't apply it too thickly, because that can result in visible runs and drips that can also dry in place.
After the first coat's dry, wet-sand it with a fine grit abrasive pad and wipe it clean with a tack cloth (a sticky cloth available at home centers for removing dust from wood surfaces).
3 or more coats will usually be required, so check the product's label and repeat the coating process as often as needed.
Resin and Tung oil finishes are generally rubbed into the wood with a cloth and allowed to set a few minutes before wiping away the excess.
Allow that to dry 24 hours. Buff that with a polishing cloth and apply the next coat.
3 or more coats will also usually be required with these finishes, but in any case you should follow the manufacturer's recommendations as listed on the label.