Bare Wood Sanding

Do-It-Yourself Project

Sanding Steps to a Fine Finish

Sanding is often the most overlooked surface preparation operation. The quality and uniformity of the sanding process directly affects the quality of the finished piece.

Individual wood parts in your unfinished wood furniture kit are factory sanded. However the assembly process requires gluing, clamping and general handling of the workpiece that can leave scuffs, dents, dings and oil deposits that need to be repaired and removed prior to staining or painting. These surface imperfections will result in an uneven appearance of the stain, paint or other finish that is being applied.

 “Dry fit” all parts to make sure they fit together properly. Assemble of chairs, rockers and stools often require some final shaping for proper fit at the joints. This may require some extra sanding to ensure a uniform fit and finish.

Getting Started

Work in an area that is well ventilated, dry and relatively warm. Ideal conditions for storing sandpaper are also ideal for wood with relative humidity below 50% and temperatures between 18°C (65°F) and 27°C (80°F). Since the process of sanding involves the removal of material it creates airborne wood dust. We recommend safety glasses or goggles, work gloves, a work apron or close fitting clothing and an approved dust/mist respirator. Also offered is a Wood Finishing Tack Cloth, which has a special tacky coating that picks up sanding residue and loose dust to ensure a quality smooth finish.

TIP:  When hand sanding large flat areas use a rubber sanding block  or make one from a block of wood to support the sandpaper. Glue a piece of pressed felt onto the surface of the block to act as a cushion behind the sandpaper for uniform support for uneven surfaces. The felt cushion will keep the sandpaper from digging into high spots and allow it to get into low spots for a consistent and uniform finish.

Wood Types

Know the type of wood you are finishing before starting sanding. The type of wood you are sanding has a direct relationship to the grit used for final sanding. There are two basic types of wood - softwoods and hardwoods.

Typical softwoods are Pine and Fir. Softwoods can be finish sanded with 150 or 180  grit prior to the application of primer. Please see Grit Guide below for more information: 

Hardwoods used in furniture fall into two categories. Closed grain and open grain. Cherry, Maple, Birch and Alder are considered closed grain hardwoods. Oak, Ash, Mahogany and Walnut are considered open grained hardwoods. Open grained hardwoods can often be finish sanded with 220 grit. Since sanding actually scratches the surface, keep in mind that the coarser the final grit size the darker the finish when using stain. Conversely the finer the grit size the lighter the finished stain. The coarser the scratch pattern the deeper the stain "penetrates" the wood. To achieve the desired stain color, it is recommended to test the sanding steps on a scrap piece of wood to determine the correct sequence of sanding steps. Once the stain/color has been applied to your workpiece the only way remove it is to strip or sand it and start over.  Using a test block saves time and agony.

7 Simple Steps to a Smooth Finish

Step 1

Always sand in the direction of the grain. Be extra careful when sanding face frames or assembled pieces where the grain direction changes at the joint between the two pieces. Cross grain scratches are difficult to remove without extra sanding and will show through your final finish.

Step 2

Start with the finest grade (grit) of sandpaper  that allows you to get the job done effectively. Starting too coarse only means extra sanding steps to achieve an acceptable finish. This is very important especially when sanding veneers. Since most veneers used today are very thin, extra sanding steps as a result of starting too coarse may result in sanding through the veneer.

Step 3

Scrape off any glue residue from the assembly steps and sand uniformly to remove any traces. Glue residue limits the ability of the stain to penetrate the wood surface. Clean all surfaces with a tack cloth to remove wood dust.

Step 4

For sanding flat areas, use a sanding block  to ensure an even and smooth surface. For larger areas, use an occillating sander like a palm sander. Use the sheet cutting diagram shown below as a guide for cutting sheets to fit ¼ sheet, 1/3 sheet and 1/2 sheet sanders and for hand blocks.

Step 5

Sand the entire surface of the workpiece. Do not sand only the area that may have contained a small surface defect. Sanding only a small area will result in an uneven and blotchy appearance.

Step 6

Sand with successivelyfiner grades of sandpaper  skipping one grade between sanding steps. Since you have pre-determined the final sanding grade for you project by using your test block determine your starting grade for sanding by testing to see if that final grit size effectively removes the surface defects. If it doesn't, then use the next coarsest grit in the grade sequence and start again. Remember you are trying to minimize the number of sanding steps to achieve the desired result. The coarser you start, the more sanding you have to do between the coarse grade and finish grade to get an acceptable finish. Do not skip more than one grade between sanding steps. For example if you started with 100 grit and that is not your last sanding grade then you can skip 120 grit and go to 150 grit to complete the job.

Step 7

Clean all surfaces with a tack cloth.

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