Tuesday, July 21, 2009

General Applications for Coated Abrasives

Purpose of Sanding

  • Prepare the wood surface

  • Clean the wood surface

  • "Level out" the first coat of top coats

  • Promote good bond between coats on some type of finishes


  • Final step in finishing using coated abrasives

  • 150 grit or finer

  • In woodworking, polishing is the final sanding of bare wood prior to staining or finish

Intermediate Sanding

  • Grit ranges from 50 to 120 grit

  • Stock removal is of medium quantity

  • Rule of thumb – Skip only one grit at a time

Rough Stock Removal

  • Woodworking requires dimensioning of lumber or glued panels to proper thickness

  • Grits 24, 36 and 40

Sanding of Penetrating Oils & Finishes

  • Bare wood should be sanded to at least 180 or 220 grit

  • Sanding beyond 220 will tend to burnish the wood surface

  • Pores will close and "slicken" the surface

  • Oil or stain penetration will decrease

  • Common to use 400, 600, 800, 1200 grit wet-or-dry Silicon Carbide sheets to "sand in" the oil or stain

  • Drives the stain or oil into pores of the wood and smoothes the wood surface as grain is raised

  • Grain raising is very common with water-based stains

Tips for Sanding Putty & Filler

  • Excess residue of fillers should be sanded with steel wool or a non-woven abrasive pad

  • After filler is fully dry, scuff sand with 220 grit Stearated sandpaper

  • On closed-grain woods, sand with 320 Stearate to reduce likelihood of cutting through the filler into bare wood

  • Putty should be sanded with 180 to 320 grit Stearated paper