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Wood Finishing. Finishing Safety. When in lab, wear your safety glasses. Wear Proper clothing. Wash hands immediately after use of any finish. Keep solvents away from heat. Use in a ventilated room. After using any finish, close all containers and put away properly.
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Finishing Safety • When in lab, wear your safety glasses. • Wear Proper clothing. • Wash hands immediately after use of any finish. • Keep solvents away from heat. • Use in a ventilated room. • After using any finish, close all containers and put away properly. • Clean up any spills that may be a hazard in the lab.
Finishing Wood • The two main reasons for finishing wood include: • To protect it • To add to it's beauty * When finishing, take your time, DON’T RUSH!
Three Types of Wood Finishes • Transparent Coatings- coatings that can be seen through. Ex. Shellac, varnish, lacquer • Penetrating Finishes- these soak into the wood rather than just coat it. Ex. Linseed Oil, Danish Oil • Opaque Finishes- covers the surface completely, cannot be seen through. Ex. Paint, enamel
Transparent Coatings • Varnish- a preparation consisting of various resins, dissolved in an oil or in alcohol. When applied to the surface of wood, it dries and leaves a hard, glossy transparent coating. • Shellac- a varnish made by dissolving this material in alcohol or a similar solvent. • Lacquer- a protective coating consisting of a resin, sometimes with pigment added. • Resin – Resin is a thick and sticky yellowish- brown substance used to chemically bond materials together.
Penetrating Finishes • Linseed Oil-A yellowish oil extracted from the seeds of flax and used as a drying oil in paints and varnishes and in linoleum, printing inks, and synthetic resins. • Danish Oil-is a blend of oils and resins that penetrates, seals, and preserves wood surfaces.
Finishing Supplies • Abrasives • Brushes • Solvents • Wax • Oils • Paints
Brushes used for Finishing • Two main brushes used are bristle brushes and foam polybrushes. • Natural bristle brushes-are made with hog hair, commonly used with oil base paints. • Synthetic bristle brushes-are made of nylon or polyester, commonly used with water soluble finishes, and most oil base finishes. • Foam polybrushes-made of plastic foam tapered on both sides to a sharp point, can be used on most finishes.
Finishing Considerations • Project design • Type of wood being used • Projects intended use • What do you want your end result to look like? • Will it be exposed to heat, or moisture?
Preparing the Surface • After assembling the project, check for the following before applying your finish: • Dried glue • Dents • Chips • Scratches
Preparing Surface Cont… • Remove access glue • Remove Mill Marks • Correct dents, chips or gouges; • Using hot steam, • Wood fillers may be needed, such as a wood patch. Fill deep cracks and gouges with wood filler or water putty; leave the filler slightly high to allow for shrinkage as it dries. When the patch is dry, sand it smooth.
Sanding • Sanding is crucial to preparing your wood for a finish, whether it be hand or power sanding. • Anyone tell me why? • Different grit sand paper • Coarse- (80 grit) • Medium to fine- (100-180 grit) • Very Fine- (220-280 grit)
Applying Stains and Clear Finishes • Staining- is the process to change the color of the wood without changing it’s texture. • Types of stains: • Pigment stains -are made by adding color pigments together. • Ex. Mineral spirits, etc • Penetrating stains – are made by mixing aniline dyes in oil. • Ex. Minwax, etc
Applying Stains Cont… • Wood Stain Finishes: • Wood Toned - Lightly pigmented wood-toned finishes add color to the wood, while enhancing its natural beauty. • Semi-Transparent- Semi-transparent finishes allow both the natural grain and texture to show through. • Solid Color-The most durable finish, solid color stains reveal the texture of the wood, but generally conceal the grain.
Clear Finishes • Two basic types of clear top-coat finishes: • Those that penetrate the wood • Ex- linseed oil, danish oil • Those that stay on top of the surface • Ex. Shellac, varnish, polyurethane and lacquer
Applying Sealer • After stain has dried completely, a sealer should be applied over the stain before a clear finish is applied. Why? -This prevents the stain from bleeding into the clear coat which causes the end result to be cloudy.
Applying a filler • This is put on over the sealer to seal the pores of the wood before applying a clear finish. Apply filler first along the grain of the wood. Then work across the grain to fill the pores completely.
Applying Paint and Enamel • These may include, water based latex or oil based. • An enamel paint is a paint that dries to an especially hard, usually glossy, finish. • Before applying paints, a primer should be applied, priming ensures better adhesion of paint to the surface, increases paint durability, and provides additional protection for the material being painted.
Applying paint and enamel cont… • Generally two coats of paint or enamel are applied. • Between each coat, a light sanding job will help with the looks of your finish.
Wood Finishing Review • Keep in mind, all safety precautions when working in the lab. • Two main reasons to finish your wood; • To protect it • To add to its beauty • There are many various finishes, your choice depends on many factors such as; • Type of wood used • Project design • Projects intended use • Visual appearance • Will it be exposed to heat or moisture?
Wood Finishing Review Cont… • Before applying your finish make sure you prepare the surfaces being finished. This includes; • Check for imperfections • Correct those imperfections • Apply finish • Take your time, don’t Rush!!! Any Questions???