Surfaces with varnish, polyurethanes, or other sealants or finishes require sanding before any paint can be properly applied. If not, the newly-painted surface will bubble, peel, crack or generally not stick. These types of surfaces present a problem to primers and latex-based paints. Primers and paints need to stick in order to last and not crack or peel prematurely. Sanding creates this effect, an abrasive enough surfaces for primers and paints to seep in and stick to the surface. Oil Bond has been recognized by This Old House as a Top Product , and has been featured on many professional painting contractor websites and blogs.
Types of Paint, all about paint, Oil-Based Paint, Varnish, Enamel Paint, Latex Paint, Epoxy TeamCCF
Types of Paint. Oil-Based Paint. Contains pigments usually suspended in linseed oil, a drier, and mineral spirits or other types of thinner. The linseed oil serves as the binder for the pigments, the drier controls drying time, the thinner controls the flowing qualities of the paint. As the thinner evaporates, the mixture of pigments and oil gradually dries to an elastic skin. As the oil absorbs oxygen from the air or cures , the curing action bonds a tough paint film to the applied surface. Oil paints are used inside and outside and are regarded as the traditional house paint.
Oil-based paint once ruled the world of interior paint for high-impact areas such as trim work , doors , and cabinets. Yet no longer. When it dries, oil-based paint emits a host of VOCs volatile organic content that are harmful to the environment. The paint is often messy and smelly since mineral spirits or paint thinner must be used for clean up, not water. If a house is old enough, it is inevitable that it will have oil-based paint somewhere since water-based latex paint wasn't introduced until the s.
Yes, you absolutely can paint over varnish with latex -- provided you properly prepare the surface first. Varnish may contain paint-repelling contaminants that must be removed to ensure the latex paint adheres; consequently, you must dull, clean and prime the surface before you can make the switch from varnish to latex paint. Seal the surface with shellac primer to prevent tannins from bleeding through to the paint.