|PREPARATIONS FOR FINISHING
IMPORTANT: Allow ample time with the sanding procedure to apply the first coat of stain or other finish the same day that sanding is completed. This prevents a raised grain condition which creates a rough surface.When machine and hand sanding are completed sweep and vacuum the floor. Wipe up and/or vacuum all dust on windows, sills, doors, door frames, and baseboards.Inspect the floor carefully. Spot-fill missed cracks and nail holes with a commercial flooring filler, applied sparingly with a putty knife. When dry, hand sand with fine sandpaper, same grit as final sanding.
IMPORTANT: Check with finish manufacturer or supplier to make sure fillers are compatible with finish materials.
For future re-finishing, it is essential to know the brand names and color of the stain and other finishing products used, or if the floors were prefinished at the flooring manufacturing plant.
Immediately after sanding is completed the finishing process should begin. This process involves applying a protective coating and a color, if desired, to the flooring. Finishing produces a uniformly enhanced surface and seals the wood to make it less absorbent to moisture and foreign materials.
GENERAL TYPES OF FINISH MATERIALS
IMPORTANT: Read entire label before applying finish and use only compatible products. Compatibility questions between different materials should be referred to the finish manufacturers.
Always follow ALL of the manufacturer’s safety precautions, especially for skin contact, ventilation, breathing apparatus, fire hazards and disposal.
Penetrating Seal. This sealer soaks into the wood pores and hardens to seal the floor. It wears only as the wood wears, will not chip or scratch and is generally maintained by thin applications of wax. After years of wear the floor can usually be restored without sanding by cleaning it and applying another coat of sealer or a special reconditioning product. Worn areas can usually be refinished without showing lap marks when new finish is applied over the old. A penetrating sealer may also contain stain which colors the wood while sealing it.
Stain or stain sealer combination. Staining is the first step in the finishing process if other than a natural finish is desired. The oil stain with a penetrating sealer in combination is generally easiest to apply and accomplishes two things, coloring and sealing, in one application. Stain only (without sealers) requires more care with the application in order to avoid uneven coloration and lap marks. A stain only generally requires 8 hours or less to dry (Read directions). The combination products (stain and sealer) require at least overnight or up to 48+ hours to dry in stagnant, damp, or humid conditions.
Fast-drying sealers and stains. These products should be used only by a person who is accustomed to handling and applying them. The mechanic should be able to complete the job within the allotted drying time to avoid lap marks or a splotchy appearance.
With a sealer/wax system, most manufacturers recommend two coats of a penetrating sealer, then wax. A reconditioning product is generally available for use when traffic or other conditions cause discoloration or wear of the finish. These reconditioning products restore the floor to its original appearance without the need for sanding.
With a surface finished system, one coat of sealer generally followed by two coats of the surface application produce satisfactory results. FOLLOW THE MANUFACTURER’S DIRECTIONS.
Application:Stain or penetrating sealer can be applied by hand wiping with rags, by brushing, or with a lambs wool applicator. Start application in one corner along one edge of the room and move with the direction of the flooring. Use a paint brush to apply to flooring at wall lines. “Cut in” about 2″ or 3″ from walls to avoid smearing moldings. Apply liberally with rags along the length of the starting wall in a strip you can reach across.
When using an applicator apply a heavy streak of material along the grain; leave about one foot of space from the wall-side application. Go to where this stripe was started. Do not re-dip; use the excess material to fill in the empty space, wiping across the grain. Maintain a uniformly stained area to a particular line or run of boards across the room.
Distribute material evenly, do not leave puddles or a heavy excess on the surface. Wiping up the excess can follow almost immediately after the applier moves away from the corner area. The length of time the stain is allowed to remain on the floor, to some extent, will determine the degree of color tone. Use clean rags and wipe up the excess material left on the surface of the flooring. Repeat the application and wiping process, working parallel to the stained area across the room. Be sure to overlap by one strip into previously stained area and wipe the overlap well or else an area that appears darker (a lap mark) can result.
NOTE: Do not allow stain/penetrating sealer to dry before wiping. DO NOT allow water drops, sweat, or bare hands and knees, etc. to come in contact with the unstained and stained areas or discoloration and imprints will result.
After completing the first coat allow to dry overnight or longer, as necessary. Use a #1 steel wool pad or white or brown fiber buffing pad on a floor buffer and buff the floor. Clean, vacuum, and dust residue. & If only stain was used, apply sealer as the next step.
If the SEALER / WAX SYSTEM is the final finish, apply a second coat of sealer and allow to dry. Neutral color should be used if no additional colorant is required. After drying, if rough to the touch, this second coat should also be buffed with #1 steel wool or a fiber pad, and the floors cleaned of residue. Paste wax or liquid buffing wax is then applied and buffed to a satin sheen with the buffing machine. To apply a thin coat of paste wax place a walnut size glob of wax in an old cotton athletic sock. Heat from the hand will melt the wax as the pad is rubbed over the floor; let dry before buffing.
SURFACE FINISHES – These finishes remain on the surface of the floor and form a protective coating.
Polyurethane, “Swedish Finish”, Moisture Cured Urethane, and Water Based Urethanes to name a few are blends of synthetic resins, plasticizers, and other film-forming ingredients. All are durable, moisture resistant finishes. These finishes are generally available in high-gloss, semi-gloss, satin and matte except moisture cured urethane. Any one of them is a good choice for a kitchen where there is exposure to water splashing or spills.
Oil Modified Polyurethane is generally the most common surface finish. It is durable and moisture-resistant, and generally the easiest to apply. This type finish tends to amber slightly as it ages.
Water based finishes (Urethane and/or Acrylic combinations) These are clear, durable, non-yellowing and are non-flammable at time of application. They generally have advantages similar to Oil Modified Urethanes without the odor of mineral spirits, and they dry much faster.
Moisture Cure urethanes are harder and more moisture resistant than the other surface finishes and are generally available only in gloss. They cure by absorbing minute quantities of moisture from the air, which causes them to dry and harden. Relative humidity is critical to the curing process. Follow manufacturer’s directions. These finishes are extremely difficult to apply properly and are best left to the professional.
“Swedish Finishes” (Acid Cure Urethanes) are also durable finishes, generally harder than polyurethanes. They are clear, fast drying and resist yellowing. Type of undercoat, working time, number of coats, and other factors are all critical and make application difficult. These finishes should be applied ONLY by the highly skilled.
If a SURFACE FINISH is to be applied (i.e. Polyurethane, Water Based Urethane, etc.) after the application of stain and sealer, be sure the floors are completely dry. Follow by buffing the sealed floor with #1 steel wool, a buffing pad or a fine screen and completely vacuum up residue.
NOTE: If water based urethane is to be applied NEVER use steel wool. Steel fibers rust on contact with water and will discolor the finish. Use an abrasive nylon screen or fiber buffing pad (white or brown).
Oil Modified Polyurethane APPLICATION. Follow manufacturer’s instructions and safety recommendations. Turn off open flames (don’t forget pilot lights) and shut off AC/heating units, if recommended. Stir material well but avoid bubbles. Pour into clean paint tray or bucket. Apply to flooring with brush or lambs wool applicator. Start application along one edge of the room with the direction of the flooring. Cut in at the wall with a paint brush. Apply Polyurethane along the length of the starting wall in a strip you can easily reach across.
Brushing. Fill 1/3 of brush with finish, dab off excess drip, apply a liberal amount with smooth even strokes along the grain. Watch out for splattering. Do not over- brush which will introduce bubbles. Work from where finish has not been applied into the area that is still wet, feathering out the lapped areas.
Applicator. Fill applicator with finish, dab off excess drip, and apply across the strip direction in short strokes, working toward previously wet area. Straighten cross strokes with a single gliding stroke along strip direction, feathering into previously applied wet area and lifting the applicator up.
Apply finish in parallel strips across the room. Always maintain a “wet” edge. Don’t retouch missed areas (holidays) if finish has begun to skim over. The next coat will fill these areas. Allow to dry overnight.
When dry walk over the floor, especially perimeter exterior walls and feel corners. If the finish sounds or feels tacky it is not dry. WAIT FOR IT TO DRY: Buff the completely dry finish with #2 steel wool pad or a used 120 grit screen, or hand sand with 120 to 150 grit sandpaper.
NOTE: If finish does not powder when buffing, additional drying time is recommended. Tacky finish can knot up and accumulate on the buffing wool, screen, or sandpaper and scratch the finish.
Merely dull all the finish. Don’t forget to hand sand or steel wool corners and edges. Too much buffing removes finish material to the extent the sealer/stain is exposed or removed.
Vacuum up all dust. Tack floors with a lint-free towel (wrapped around a bristle broom) and slightly dampened with water or 100 % mineral spirits. Let floor dry completely.
Apply second coat. A third coat may be desired for increased protection and durability. Buff between coats to dull the surface.
Water Based Urethane APPLICATION. Follow manufacturer’s instructions. Turn off AC or Heating units, if recommended. Pay particular attention to coverage figures, open time, and when-to-buff instructions. Use catalyst, if required, stir in and let stand if recommended. Pour finish into non-metal tray or bucket. Apply to flooring with brush recommended for water based materials, paint pad, or manufacturer supplied applicator.
Most water based materials are applied by pouring a “small river” along the starting wall near the “cut in” area. The applicator “plows” this material along the direction of flooring the length of the room with excess directed toward unfinished area. As finish material is used, re-pour the “small river” and continue application. Open doors or use fans to exhaust moisture laden air when finish films over and is dust free to facilitate curing. Some manufacturers recommend buffing the rough raised grain after the first coat. Some recommend application of a second coat in 3-5 hours without buffing. Follow buffing directions and use fiber pads or screens. A third coat is generally recommended. Application of more than two coats in one day is generally not advised.
NOTE: Do not over-work material. Keep renewing the small river of material and be sure to maintain a wet edge in order to avoid gaps and excessive foaming.
BLEACHING . Bleaching is generally used to lighten the natural coloration and subdue the darker characteristics of flooring. Bleaching is generally followed with an application of a white or pastel stain. Application of these products should be done by the professional. Before using a bleach be sure the flooring is clean and free from oils, grease, and old finish that might repel the bleach and give an uneven effect. Use only bleaches specified for wood flooring and follow application and drying directions carefully. Some products need neutralizing after application. Extra time is required to complete the bleaching process and allow complete drying.
It’s a good idea to make a test area in an inconspicuous place, since the length of time the bleach remains on the floor and the amount used will affect the degree of color removal. Also, bleaching White Oak can result in a greenish coloration.
The bleaching process should be done only once.
A white stain may be applied before the surface finish. Check that all products are compatible with the stain and/or sealer used and that a non-ambering surface finish is used. The final sanding cut with an 80 grit paper is advised with white stains. This promotes absorption of the larger coloring particles of the stain into the flooring. Be sure the excess stain is wiped from the surface. Follow by buffing when stain is dry. Stain residue on the surface of flooring can interfere with adhesion of the final finish.
NOTE: Seasonal cracks, surface discolorations, and dirt are VERY noticeable and may be objectionable in a white floor.
You should first determine what type of finish is on the floor so appropriate materials can be used.
To determine if a floor was originally finished with a penetrating seal, scratch the surface with a coin or other sharp-edge object in a corner or some other inconspicuous space. If the finish does not flake off, a penetrating seal was probably used and a reconditioning product can be applied to restore its original beauty. TEST AN AREA.
If the finish flakes in the corner, a surface finish was probably applied to the flooring. Next check for wax. Wax interferes with intracoat adhesion so recoating over wax is not recommended. Attempt to smudge the surface in the same corner with your finger. If a smudge is evident, wax is probably present and complete re-sanding and finishing is indicated.
With Surface Finishes which have not been waxed you can recondition by re-coating if the finish has not been worn away to expose bare wood.
To re-coat finishes first remove furniture, etc. Next clean floors with a non-residue cleaner designed for polyurethane on wood floors or non-aromatic 100% mineral spirits. Dull the finish surface with steel wool, a sanding screen or paper as required by the type of finish used for re-coating (See appropriate finish section above) Apply a compatible finish using appropriate application techniques as described in finishing.
CAUTION – Adhesion between coats of surface finishes is affected by wax, grease, and some maintenance products, as well as some types of stains, bleaches or sealers. One brand or type of finish may not be compatible with another. Check with manufacturer for compatibility. Make a test in a closet or some other inconspicuous place to be sure the finish will adhere and dry properly. This is particularly important when refinishing an old floor since some of the old finish may have penetrated the wood below the level to which it is sanded.
VARNISH AND SHELLAC – These products were commonly used as floor finishes before today’s modern formulations were introduced. However, they are rarely used today, and generally are not considered as durable as the modern finishes. Shellac is not recommended for use as a floor finish since it shows water spots readily. NITRO-CELLULOSE LACQUERS are hard and brittle and scratch easily (very flammable when applied).
STENCILING – Decorative borders or overall floor patterns can be applied to hardwood floors with the use of stencils. However, this job should be done by a professional finisher familiar with these procedures.