Prep & Sanding - Portland Furniture Store

Prep & Sanding - Portland, OR Real Wood Furniture Store

Begin with the end in mindBasic sanding preparation Sanding tutorial (only for those that want to know more)Color selectionOther preparationThe tools you needWork area tips

Begin with the end in mind

Wood finishing is fun and easy. Don't race through finishing a piece of furniture. Imagine how it will look finished in your home. Set up a good prep area. Turn on some music. Get creative and enjoy the journey. Make something that will bring beauty to your life, save you money while having fun in the process. Take an a little extra time to get a good result.

If you are an experienced wood finisher, refer to our retail brochures or General Finishes's Video Library for quick and simple finishing instructions. For those of you that like to know more, we'll take you step-by-step through the wood finishing process, including preparing the wood, selecting the finish and applying traditional or decorative finishes. Whether you're planning to finish furniture for your own home, make gift items, or take up woodworking as a hobby, you'll find wood finishing to be a rewarding experience. It's a practical skill you'll take with you throughout life. Anyone can save money by finishing their own furniture.

The most critical part of finishing a piece of furniture happens before you open a can of stain or paint. Proper prep sanding is often the factor that separates acceptable results from professional-looking results.

Tips for kit (unassembled) furniture: If you are assembling furniture, do so with an eye to the finished product. Do any major sanding required to make solid and flush joints and corners. Some find it easier to sand before the furniture is permanently assembled. Use caution when sanding individual pieces to avoid rounding over crisp edges that may form gaps when joined and glued.

Whether the project is a ready-to-finish piece of furniture, a freshly stripped antique, or a kit that needs assembly, now is the time to make minor repairs and sand the piece. Use crack filler to fill voids, nail holes and other imperfections. Crack filler should be sanded until it remains only in the void, and not on the surface of the wood. Excess glue on the surface of the wood must either be flushed and washed away with clean water while it is still wet, or allowed to dry and cut away with a sharp chisel or knife. Any remaining spots or smears must be completely sanded away. Areas contaminated by glue will not accept stain.

Sanding Preparation

It is paramount that start with a strong base of proper sanding in order to achieve the perfect finish. Review our sanding tutorial or prep sanding video for details. All surfaces should be clean and free from dirt and oils. Prep sanding is done with progressively finer grits. Prepare the surface with medium-grit sandpaper first, then proceed to finer grades. On most raw woods, start sanding in the direction of the grain using a #120-150-grit sandpaper before staining and work up to #220-grit. Beware of over-sanding. Sand wood too smoothly and your finish won’t adhere.

  • Soft woods such as pine and alder: start with #120 and finish with no finer than #220 (for water base stains) and 180 grit for oil base stains.
  • Hardwoods such as maple and oak: start with #120 and finish-sand no finer than #180 (for water base stains) and #150 grit for oil base stains.
  • End-grains (areas where the wood has been cut against the grain), such as the front side of a table, tend to soak up more stain than other surfaces. Give those areas an additional sanding to control stain absorption.
  • Make fast work of prep sanding and buffing between finish coats with an orbital power sander with dust bag. Be sure to use the correct grade of sandpaper when buffing out between top coats or milk paints. We often prefer to hand-sand final layer of top coat. Do not use an orbital sander for distress sanding flat, painted surfaces. The orbital sander will dig in as you apply pressure to get through the paint, leaving round areas of wear, whereas natural distressing runs with the grain of the wood.
  • Sanding Blocks also make quick work of finish sanding. A fine-grit foam sanding block is great for corners, crevices and small areas.

Sanding Tutorial

A sanded surface is nothing more than progressively finer and more numerous scratches. Therefore, skipping a grit leaves deep valleys that successive grits are hard-pressed to remove.

A general rule for the use of sandpaper is: the finer the sandpaper used, the lighter the stain color will be. Conversely, the coarser the sandpaper used the darker the stain color will be. A coarse sanding will look less refined than the smooth surface that comes from progressing through increasingly finer grits of sandpaper. Final sanding will bring the surface to the desired smoothness. Sanding must be thorough, even and with the grain. If these criteria are met, no further sanding will be necessary.

Since there are so many grades of sandpaper available, some knowledge of what the various designations mean and a little practice are useful in order to sand effectively and efficiently. This chart is based on our experience and is intended as a guideline only.

The number of identification or grit on the back of sandpaper sheets indicates the smallest opening through which the abrasive particles will pass. For sandpaper marked 220, the abrasive particles will pass through a screen with 220 openings per linear inch. The types of abrasives commonly used for furniture finishing are garnet, aluminum oxide and silicon carbide. In general, red garnet paper is used primarily for hand sanding. Gray to white aluminum oxide is used for either hand or power sanding; black silicon carbide is the abrasive of choice for very fine sanding in the woodworking field.

Coarse sandpapers below 100 grit are rarely used for fine furniture finishing. They may, on occasion, be useful for distressing the surface, rounding harsh corners or breaking down extremely rough areas. The grades of sandpaper used most for furniture finishing fall between fine and very fine, that is from 120 through 220 grit; with 320, 400 and 600 grit reserved for special purposes.

For hard-to-stain woods, such as alder, birch, maple and poplar, finish sanding with 120-grit sandpaper will usually accommodate the problem. For finish sanding on most furniture hardwoods (e.g. cherry and mahogany) use 180- or 220-grit sandpaper. The use of grits up to 600 is not standard practice. Usually you will have to make a concession either to surface smoothness or to color acceptance. Factory-sanded furniture still requires finish sanding. Do the initial sanding with medium-fine paper and finish with one or more of the finer grades. Be sure to sand the whole surface with the same grit. If you miss a spot, the stain will be darker on the rougher areas.

Do not use steel wool when preparing wood for waterbase finish, as steel particles may cause rust spots.

Color Selection

The final color of a piece is determined by four factors:

  1. The color of the stain
  2. The nature of the wood species; different species of wood absorb stain differently based on porosity and oil or resin content
  3. How long the stain is left on
  4. The extent of wiping when removing excess stain
  5. The number of coats
  6. The topcoat used: one that dries clear vs. one that ambers

Get creative by mixing General Finishes stains together to create custom wood tones or colors. Be sure to mix enough to complete the entire project. Always be sure to test the stain on a hidden area first.

Other preparation

  • Look for ways to disassemble the furniture to make staining easier. Just by removing a few screws you can remove the back of a piece of furniture.
  • Remove dust with an air hose, damp cloth or oil-free tack cloth. Do not use tack cloths that contain any kind of oil when using water based finishes. Oil-free tack clothes are available from your local unfinished furniture or woodworkers store.
  • Optional: Raise the grain. On certain woods, such as oak and ash, pre-wet the wood with a damp cloth to raise the grain before final sanding. This will provide a smoother final finish. Allow the dampened wood to dry 30 minutes before the final sanding.
  • Stir the contents of the can well every time you open it. Whether you are using oil-based or water-based products, wood stains and milk paints contain colored pigments and dyes that settle to the bottom of the can and must be thoroughly mixed before application. It takes several minutes to thoroughly mix the contents of the can so the color remains consistent to the last brush stroke.
  • The open time with water-based products is shorter than oil, so stain one surface at a time. Don't be stingy when applying water base products. Load up your application tool with product and apply liberally, keeping the surface you are working on wet with product until you are ready to wipe that section off with a cloth. To get an evenly stained surface, it is important to wipe off the stain thoroughly and consistently in the direction of the grain. A second coat, applied after the first one is completely dry, will give you a darker and deeper color.
  • Mix colors to make it your own custom finish. Don't let a color chart slow you down. General Finishes water based products - Milk Paints, Wood Stains, Dye Stains, Glazes and Topcoats can be intermixed to create a unique finish. Let your creativity come out and play!

The tools you need

Before starting almost any wood-finishing project, have these items on hand. Get enough gloves, sanding blocks and sandpaper, lint-free cloths, paper towels, stir sticks, plates to pour your finish into, brushes and whatever else you might need.

  • Quality paper towels or lint-free absorbent wiping cloths.
  • Use gloves, even with waterbase products. Get several pairs if you are planning to layer colors on your project. Applicators will rinse well, but the dyes and pigments in waterbase products can stain your hands. Here is a tip: when cleaning up your work area after using waterbase products, just grab all the wet application cloths in your gloved hand and peel the glove off your hand over the cloths for quick disposal. Never do this when using oil based products. All oil based application materials must be carefully disposed of in accordance with the standards of your local fire department.
  • Aluminum foil and paper plates. Paper plates covered in aluminum foil provide the perfect container for application. Throw away the foil and reuse the plates. Remember, oil based products are combustible. Dispose of them in accordance with the standards of your local fire department.
  • Choose your favorite application tools. You can apply any stain with an old rag or bristle brush, but we recommend the following.
    • Foam brushes for small surfaces and corners. Flimsy foam brushes fall apart in minutes - a good foam brush can be used several times. Buy enough quantity to make life easy on yourself. We usually have several either in use, rinsed or drying. They can be stored after drying and reused several times.
    • Small, old bristle brush for dragging excess stain or paint out of corners.
    • Handi Painter pads for large surface areas. They make it easy to quickly apply a lot of product to a section. They work well for oil base or waterbase applications. You can cut them in half to make two applicators for mid-sized surfaces. Note that when Handi Painter Pads are new, or cut in half, they shed. Be SURE to brush or rinse off any fuzz before using, or put a nylon footie over the padded surface while working to keep the fibers from embedding into your finish and reduce bubbles in your top coat. If you are using waterbase products, they can be washed and reused many times.
  • Don't work like a dog sanding anymore. Use soft back sanding sponges! They fit on standard palm sanders, are very flexible, easy to clean (rinse with water), and last a long time. They work great for buffing between coats of finish and are available in four grades, and fine enough to rub out finishes. Our favorite for final finishing is the superfine grade.
  • Use Blue Scotch 3M Painters masking tape to section off your project. Great for two-tone finishes or for creating specialty looks such as this checkerboard or chevron pattern.
  • Clean-up materials: paper towels, cotton swabs, mineral spirits and sealed metal containers, such as empty paint cans (for cleaning brushes, and, with the addition of water, for disposing of rags and waste soaked with oil finishes).

Work Area Tips

  • Cover the floor with drop cloths, newspaper or plastic sheets. Make sure you cover the floor area around your project enough to easily walk around it. Be mindful of the bottom of your shoes; don't walk through drips and then track onto the floor, unless you don’t mind getting stain or paint on it.
  • If your project is small enough, put it on a lazy-susan table with wheels to easily access all sides.
  • When staining knobs, punch the knobs into the bottom of a cardboard box for easy finish application. Simply cut slots in the cardboard, and slide the screws (with the knobs attached) into the slots to make them freestanding.
  • Use old boxes for drying racks for small pieces such as drawer fronts. Recycling bins work well too.