The process of hardwood floor sanding and refinishing may present a certain level of uncertainty for anyone who has not had first hand experience with it.
There are many steps involved in sanding and preparing newly installed or pre-existing hardwood floors. Moreover, the refinishing process itself will present several possible options to achieve the results desired for your home's specific interior design concept. The following is a walkthrough provided by Inter County Floor Sanding as to the various steps necessary to complete a hardwood floor service project.
Our well trained craftsmen begin by determining the proper grit sandpaper required and number of sanding passes necessary for each specific work site. Based on experience, the mechanics will recognize the grit needed to remove any old finish, scratches and/or embedded dirt within the wood floor. Yet still not allowing too much wood to be removed with each pass. The floor may need to be sanded two to four times depending on the age and type of finish, and the condition and species of wood being refinished.
Newly installed unfinished hardwood floors will need to be sanded as well, due to slight milling imperfections and minor board edge unevenness.
We utilize the flooring sandpaper grit grades of 12, 16, 20, 30, 36, 40, 60, 80, 100, and 120. The main areas of the floor are sanded with a large professional drum sander, while the perimeter is completed with a circular edge sander. A hand scraper is used to remove old finish from corners, bullnosing on steps or ledges and generally any small area our sanders can not reach.
After the hardwood is completely sanded, a fine grit silicon carbide sanding screen is then passed over the floor with an upright buffing/polishing machine. This extra step is taken to ensure the wood has been sufficiently smoothed down and that the grain has been evened out.
The floor is then vacuumed, and tacked (passed over with a dampened towel) to remove any dust, prior to stain or finishing polyurethane being applied.
Between polyurethane coating layers the hardwood floor is abraded with a sanding screen as well. The first coat of polyurethane commonly absorbs into the wood and raises the grain. This will give the dried coating a slightly irregular and rough feeling - which is perfectly normal. The dried polyurethane simply requires a 'screening', so the floor will be made smooth prior to cleaning and recoating again.
Types of Polyurethane
We utilize the two most common types of hardwood floor polyurethane coatings. These are an Oil Modified polyurethane and a Waterborne polyurethane.
Both of these finishes are available in Gloss, Semi-gloss or Satin sheens. The image below displays general representations of what your floor may look like when polyurethane is applied to your hardwood floor.
Oil modified polyurethane:
This a petroleum/oil base finish containing plasticizers and various synthetic resins. This finish is solvent based and there is normally an odor associated with it. It will normally dry to the touch (walking in socks) in about about eight hours. However, depending on work site conditions, temperature, and humidity (all variables on Long Island) - drying may vary from six to twelve hours. Curing time for recoating, replacement of furniture, or allowing other remodeling work traffic will require skipping a day before such activities may resume. The oil-modified polyurethane itself generally has a transparent amber appearance and has a viscosity similar to new motor oil. When applied to an unstained bare wood the floor it will continue to retain this golden color. It requires a minimum of two coats to protect a floor, but three is the industry standard for sustained durability.
This a water based finish containing plasticizers and various synthetic resins. It has a milder odor in comparison to oil-modified finishes. This product normally dries to the touch (walking in socks) in about about two hours. However, depending on work site conditions, temperature, and humidity - drying may vary from one to four hours. Curing time for replacement of furniture, or allowing other remodeling work traffic will often require waiting until the following day before such activities may resume. The waterbased polyurethane itself generally has milky white appearance and has a viscosity similar to heavy cream. When applied to an unstained bare wood the floor it will appear to have a light beige/blonde color. It requires a minimum of three coats to protect a floor, but four is highly recommended for sustained durability.
After the floor sanding process has been completed, there are three basic finishing procedures available. For reference purposes they are termed “Natural”, “Stain”, and “Pickling/White”.
In this procedure a polyurethane is applied directly to the bare wood surface. No wood stain or any type of coloring is applied to the floor prior. This clear coat process will render the floor a light amber or golden honey color [as shown above]. Factors such as the hardwood species, age, and grading, will often affect the final color achieved on the floor.
Polyurethane is applied to the edges of the rooms by a hand brush, whereas a lambs wool pad (applicator) mounted on a 16" wooden block is used to apply finish to the center of the floor.
With this process a wood stain is applied to the floor, and hand wiped, prior to any protective polyurethane coatings. This stain is for cosmetic purposes only and will have no effect on the floors protection. After the stain is allowed to cure, polyurethane coatings are applied over the dried stain as in the natural process listed above.
We commonly use the industries leading manufacturer of stain Minwax® brand Wood Finish™ Stain. There are nineteen different stain colors to choose from and we recommend viewing the above link to visit Minwax's® web site and products directly.
Please note that Pickled Oak 260, Weathered Oak 270, and Classic Gray 271 require a aliphatic non-yellowing urethane and are applied with the "Pickling/White Process" decribed below.
If you prefer to have another manufactures stain applied, please let us know and we will gladly use it. Factors such as the hardwood species, age, and grading, will often affect the final color achieved on the floor.
A floor with a white-wash style look can be achieved with or without the use of wood bleach. In the basic white coloring process a ‘pickling white’ wood stain is hand rubbed into the grain of the bare wood floor. Factors such as the hardwood species, age, and grading, will often affect the final color achieved on the floor. One of the most widely used hardwood flooring today, red oak, will commonly result in a pickled floor having a primarily washed white look - with a slight pinkish tint on many boards. A white oak floor may have a slight almond or beige tint for the final white color.
If a pure and exclusively white floor color is desired, a wood bleach is applied to the floor surface before the pickling white stain is applied. This will remove most of the wood’s natural tinting and leave the wood very white once it has been screened down. There will still be variations in shading between the individual floor boards, however each one will be much lighter and whiter.
Also, many colors of white are now available to choose from. Due to the fact that the wood itself will no longer affect the resulting color of the floor, any color wash may be utilized. A white oil based paint will be used as a stain/wash once it has been properly diluted with mineral spirits. The floor will NOT look painted, but the diluted paint – now a stain – will be hand rubbed into the wood grain as in the basic ‘no bleach’ pickling process. We often use Benjamin Moore® Satin Impervo™ enamels, and are available in many colors of white (i.e. bone white, linen white, china white, etc.) Essentially any oil based paint can be used.
Some of our past customers have even requested floor color shadings of gray in dens, red in dining rooms, and blue or green in children’s rooms. The possibilities of color are quite broad, while still allowing the beauty of the floor’s wood grain to be radiate through.
After the stain/wash has thoroughly dried, coats of a specific non-yellowing waterbased urethane are applied as a protective finish.
Maintenance Recoats / Topcoating
Several years after a hardwood floor is completely sanded and finished a maintenance coat will be needed to sustain the floor's performance and cosmetic appeal. This recoating procedure, commonly called a 'topcoat', will return a hardwood floor to its newly refinished condition - provided it was performed within the ample period of time required.
A 'screening' of the original polyurethane coat, with a silicon carbide sanding screen on an upright floor buffing machine [animated right], will remove any light scuffs and surface dirt. The screening process does not remove much of the existing coatings, nor does it expose the bare wood as in the full sanding procedure. It simply creates microscopic scratches in the surface of the existing polyurethane coat. These abrasion scratches enable the new coating to properly adhere to the older one.
Please note that If your hardwood floor has ever been cleaned with an unapproved hardwood polyurethane floor cleaner or wax had ever been applied (liquid or paste) to your wood floor this topcoat procedure generally CAN NOT be performed. Polyurethane does not adhere to certain chemicals or cleaners that leave a film or wax on the floor. Unfortunately, Inter-County Floor Sanding cannot 100% guarantee that a topcoat will have absolute cohesion with an existing floor finish due to fact that we have zero control over what may or may not be on an existing finished floor.