've called several hardwood floor companies, and all insist on putting a sealer down first prior to the varnish. Is this true? The hardwood floors I laid is a very hard tropical hardwood, called Jacoba (5x harder then oak, and as dense as teak). In my opinion, the tradition of a sealer may be required for oak or pine floors, but not for v. hardwoods. Any opinions on this? Further, I am aLso told that putting more then 3 coats of varnish is not necessary, and that the slightest scruff marks etc will show up. We would like 4 coats. Any opinions on this? thanks so much.