Wood finish film-forming

Film-Forming Finishes. Film-forming finishes include paints of all description, varnishes, and solid-color stains, as well as overlays bonded to the wood surface. 

Weather affects the performance of wood finishes adversely. Both types of finish the film-forming (paints, varnishes) and the penetrating (stains, preservatives) are adversely affected by a combination of the following factors ... 

Film-forming finishes such as paints, lacquers, and varnishes have long been used to protect wood surfaces. The film-forming finishes are not preservatives they will not prevent decay if conditions are favorable for growth of micro-organisms. 

Two basic types of finishes (or treatments) are used to protect wood surfaces during outdoor weathering those that form a film, layer, or coating on the wood surface, and those that penetrate the wood surface to leave no distinct layer or coating. Film-forming materials include paints of all description, varnishes, lacquers, and also overlays bonded to the wood surface. Penetrating finishes include preservatives, water repellents, pigmented semitransparent stains, and chemical treatments. 

Film-Forming. Varnishes are the primary transparent film-forming materials used for natural wood finishes, and they greatly enhance the natural beauty of wood. Varnishes lack exterior permanence unless protected from direct exposure to sunlight. Varnish finishes on wood exposed to the outdoors without protection will generally require refinishing every 1-2 years. 

Penetrating. The penetrating finishes are the second broad classification of natural wood finishes. These finishes do not form a film on the wood surface. 

Conventional spar or marine varnishes produce a film-forming finish and are not generally recommended for exterior use on wood. Shellac or lacquers should never be used outdoors because they are brittle and very sensitive to water. Exposure to sunlight causes varnish coatings to become brittle and to develop severe cracking and peeling, often in less than 2 years. 

Thompson G.E., Wood G.C. and Hutchings R. (1980), Rorous anodic films formed on aluminium in chromic acid , Trans. Inst Met Finish., 58,21-5. 

Water Based WOODLIPE is non-film forming and is not a sealer but penetrates deeply into the wood. It will not peel or chip like conventional finishes and will function as an excellent base for most paints and finishes. 

Two basic types of finishes (or treatments) are used to protect wood surfaces during outdoor weathering (1) those that form a film, layer, or... 

Solid-Color Stains, Solid-color stains are opaque finishes (also called hiding, heavy-bodied, and opaque stains) that come in a wide range of colors and are made with a much higher concentration of pigment than the semitransparent penetrating stains. As a result, solid-color stains totally obscure the natural wood color and grain. Oil-based or alkyd solid-color stains form a film much like paint, and consequently they can peel from the substrate. Latex-based solid-color stains are also available and likewise form a film. Both oil-based and latex-based solid-color stains are similar to thinned paints and can usually be applied over old paint or semitransparent stains. 

Penetrating Finishes. Penetrating finishes, which do not form a film over the wood, include oils, water repellents, stains, preservatives, and surface treatments. 

Sealer n. (1) A liquid coat which seals wood, plaster, etc., and prevents the surface from absorbing paint or varnish may be transparent may at as a primer for a following coat or as a finish for the surface. (2) A coat, applied in hquid form, which is laid over a tar-like substance to prevent its bleeding through an applied paint film. Wicks ZN, Jones FN, Pappas SP (1999) Organic coatings science and technology, 2nd edn. Wiley-Inter science. New York. 

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