Which is better oil based or water based varnish?
Furthermore, which is better oil based or water based polyurethane?
Oil based polyurethane looks better. It has a more depth - both in color and shine and it looks the way we expect hardwood to look. Water based polyurethane has both a duller color and a duller finish. The water based polyurethane (left) is lighter and duller than the oil based poly on the right.
Correspondingly, is water based varnish any good?
Advantages of Water-Based Varnish It does not affect the color of the surface on which you applied it. It is not a fire hazard. It builds up quickly as well because it has a high solid content. After use, water-based varnish is easy to clean up.
Gloss oil-based varnish, polyurethane and Danish oil can last 10 or 20 years, though satin finishes and stains may fail sooner as pigments and flattening agents disable the driers. Water-based coatings and paints can also be viable longer than three years. Shellac, though, can go bad in under a year.