Some will contend that the natural colors, patterns and depth of wood surfaces are beautiful in themselves and need no enhancing and further that efforts to enhance actually distract from the natural beauty of the wood. We acknowledge that wood does possess a natural beauty. However, when you look at a standing tree, you don't see any of the beauty of the wood grain within. The sawyer first of all needs to cut the wood of the tree to feature the natural patterns within. Next, a woodworker will take that rough sawn wood and form it into an item of furniture which will show the beautiful grain to fullest advantage. The raw wood however, still does not display the depth, intensity and richness of its own grain pattern. Even simply wetting wood with water will show there is more to be seen than the dry wood reveals. Water evaporates quickly and the beauty it reveals is soon hidden again. Wood finishes not only preserve wood but they create a way of displaying the beauty of the wood in a lasting way.
Framing the Beauty:
Hopefully the preceding has illustrated that presenting the beauty of the wood doesn't happen without the careful efforts of a series of craftsmen. A second concept upon which our work as furniture finishers is based is that of "framing." In painting, photography and film making our attention is focused by the artist on a specific scene by placing that scene within a frame. In a similar way, our use of color, sheen and special effects can be seen as a way of framing one's attention on the distinctive features of the wood or on the design of the item of furniture. However, sometimes the wood or the item of furniture is itself a part of the "frame." In such cases the furniture may be finished not so much to stand out on its own as to aid in the creation of a certain feeling or mood in a room. We then become part of an artistic team to create that effect and the natural beauty of the wood is a secondary concern.
HOW
At this point we will become very practical and discuss what we do to enhance the appearance of the wood furniture items that come to us for refinishing.
Basic Finishing Process:
Once an item has been stripped and any repairs have been completed, we then prepare the wood for finishing. We sand all surfaces with a medium grit of sand paper and then again with a fine grit. The medium grit removes scratches and smoothes the surface, the fine grit does more smoothing to the point the surface will stain evenly and with the right penetration. The piece is then ready to be stained.
Wood stains are formulated from pigments and dyes. Pigments are very finely ground materials that are suspended in a liquid medium to create stains. Pigments are applied to the wood and wiped to force some penetration into the wood fibers and to ensure even distribution of the pigments. As the stain dries, the liquid medium that carries the pigments evaporates and the pigments remain on the wood. Pigments must be sealed in place or they will quickly wear off. Many stain vendors will formulate pigment based stains with a small proportion of a sealing material to hold the stain in place. Dyes can come in either powder or liquid form and are again mixed into a liquid medium to carry the dye onto the wood. Dyes are fully disolved in the liquid medium and will penetrate wood fibers as deeply as the liquid will. Dyes are absorbed by the wood fibers and will permanently color the wood. Because of the deep penetration and clarity of dyes, dramatic contrasts in grain patterns are accentuated and very vibrant colors can be achieved. Stains are also created by mixing pigments and dyes to create colors and effects otherwise not attainable.
After staining all surfaces are sealed. Stained surfaces must be sealed to stabilize and protect the stain. The sealing of all surfaces, stained or not, is important to minimize the effects of atmospheric moisture. We have seen many pieces come through which have sustained damage due to having only the exterior or visible surfaces sealed. Next, the item is thoroughly sanded with a very fine grit sand paper. We are then ready to begin building up the finish coats of protective coating. Because water based finishes are between 35 and 40% solids, it takes just two to three coats of finish to properly coat an item. Once those coats have been applied, we sometimes use an ultra fine grit sand paper to remove surface nibs.
Advanced Techniques:
Those were the basics for applying a standard finish. Very often however there are other steps that need to be taken in order to complete a project which has fully enhanced the appearance of the wood and the forms created by the woodworker. These are listed and defined below:
Two toning: Using a second stain color on certain sections of the item to create interest, highlight features or to make the piece appear more uniform.
Touch up: Repaired defects or damage must sometimes be disguised by creating patterns of wood grain to match the surrounding grain. This is done with the skills and supplies of an artist.
Filling: Sometimes it is preferable to fill the pores of open pored wood such as mahogany, walnut or oak. This gives a smooth, unbroken surface.
Toning: The addition of a small amount of color to one of the finish coats can be used to make the overall appearance of the piece more uniform or can be used to create depth of color.
Shading: The addition of a slightly larger amount of a deeper color to the finish can be used to create a semi-transparent shadow effect, typically around the perimeter of a table top or at certain focal features of the piece.
Highlighting: A heavily pigmented paste material is used to wipe across highly carved or figured elements depositing the paste in the recesses to accentuate the relief.
Glazing: A slightly thinned version of the paste used to highlight can be used on flat surfaces to vary the color or the intensity of color.
In-painting: Certain styles of furniture were designed with sections painted with a contrasting color, usually black. This is often seen in furniture from the 1920s.
Distressing: Wood surfaces can be artificially aged or damaged. Sanding through finished edges, adding specks and squiggles, denting with nail tips and creating scratches are some of the techniques used to distress.
Crackle or Craze: Many older finishes will show age by crackling or crazing. This effect can be replicated with clear finishes if desired.
Polishing: Certain sheens of finish are obtained by sanding with micro grained sand paper and then by polishing with compounds and perhaps buffing with a wool pad.
Options For Surface Sheen
The final consideration in finishing is the decision as to the sheen of finish. Finish sheens are measured by the amount of light they reflect, 100 being 100% light reflection and 10 being 10% light reflection. Gloss finishes are typically in the 80-90% range, Semi-Gloss finishes are above 50%, Satin finishes are below 50%, flat or matte are down below 25%, dead flat finishes are below 10%. Lower sheen finishes are made by mixing additives to the finish which reduce the ability of light to pass through the finish. One concern people commonly have about lower sheen finishes is their durability and cleanability. Unlike some house paints, there is no reduction in either durability or cleanability with lower sheen water based wood finishes.
Finishes Change Over Time:
People refinishing older furniture will often ask for a satin finish, thinking a satin finish would most accurately represent the finish originally on a piece. The reality is that all surface coated finishes tend to move toward the middle of the scale of reflectivity over time. Shellac finishes are very glossy by nature. Old varnishes were not quite as glossy as shellac but were also fairly glossy. As these naturally shiny finishes wear, fine scuffs and scratches break up the reflectivity of light and the sheen lowers. Also, one impact of ultra violet light is to create microscopic crazing within the finish which also impedes light transfer. Oxidation will cause chemical changes which darken the finish and also lower sheen. On the other hand, the additives which lower the sheen of finishes tend to accumulate at the top of the finish layer. The natural scuffing that comes with use will reveal the shiner material underneath the flatting additive and the finish will begin to appear more glossy. Consequently, all surface coated finishes over time will tend toward a more satiny appearance. In contrast to surface coated finishes, oiled finishes start out medium to low in sheen and become lower with wear.
