The Cause

Most finishes and stains dry from the top down. When the first coat is applied, whether it is a stain or finish, it seeps down into the cracks between the boards. The material therefore stays comparatively wet because there is no air movement. Usually, at this point three things happen:

• Additional coats are applied
• The floor is covered
• Time elapses

As additional coats are applied, the problem is compounded. Then covering the floor may affect the dry time by locking the solvents down in the cracks. In time the floor expands and contracts. Expansion pushes the boards together and the still wet material down in the gaps is squeezed up, forming the beads.

How to fix the problem

It has to be understood that this is NOT a finish problem. How to know? The finish looks great on the face of the boards for all coats; the only issue is the cracks.
The solution to the problem is time. Allow the floor to expand and contract and just keep removing the beads that have cured or hardened with a putty knife or scraper. DO NOT attempt to screen the beads off, this will cause circular scratches in the surface of the finish. If there are bb’s that are still soft, remove them with a scraper then wipe the area with a rag dampened with mineral spirits.

How to avoid in the future

Apply the sealer, stain and or finish as per manufacturer’s recommended instructions using the correct coverage rate. Remember more is not better. Watch for excessive cracks. These can be trowel-filled (as per manufacturer’s instructions) Also pay attention to the factors that affect dry time. Floors should be installed at normal living conditions. That means with all windows and doors in place, all wet trades done and the HVAC system running. It is important to control the job site environment. Avoid high relative humidity, above 90% R.H. and lower temperatures below 50 degrees F (10 C) that can seriously slow the drying time of sealers, stains and finishes.

Once the floor is finished, allow it to cure appropriately before covering. Check the manufacturer’s technical sheets for correct dry times.

The Problem

Finish Drying too fast.

The Cause

Most finishes will dry too fast in high temperatures, above 90 degrees F. (32 C.) and low humidity (under 30% relative humidity). A combination of both makes much worse. Also direct airflow across the surface will cause the finish to dry too fast.

How to fix the problem

Determine which of the above is the cause of the problem. Lower the temperature and/or increase the humidity. Remember to STOP the A/C 30 minutes prior to application. Re-start when product tacks over, usually about one hour, dependent on waterbased or oil-based formula usage.

How to avoid in the future

A simple tool such as a hygrometer will tell you what the job site condition is and therefore you have the opportunity to act accordingly. DuraSeal^® recommends changing your expectation of the dry time if your application and drying conditions vary from…

• The coverage rate on the label (see Finish and Curing Parameters)
• A temperature above 70 degree F (25 C) and Relative Humidity below 50%.

Note: Dry times, either fast or slow, are affected by Temperature, Relative Humidity and Air movement, either natural (window) or forced (HVAC) PLUS coverage rate. Attention to these details improves success rates.

The Problem

Finish drying too slow.

The Cause

Air/product temperature at or below 50 degrees F. (10 C) and relative humidity over 90% and/or covering the floor with brown paper or cardboard before it’s dry will cause slower dry times. (A combination of both makes conditions worse) All of these points prevent the solvent from leaving the wet film. Contaminants in the grain or between the boards can also be the cause for slow dry. Additionally, some globally resourced exotic hardwoods may not be compatible with certain finish types. Consult your hardwood flooring distributor for specific species of concern.

How to fix the problem

Determine which of the above, or combination of, is the cause of the problem.

Remember to stop the A/C (close windows and doors) 30 minuntes prior to application. Then re-start (reopen) when the finish is tack free. This usually occurs after about one to two hours for oil modified polyurethane, and 15 to 20 minutes for waterbased products. After these corrections to the site conditions have been made, the main ingredient is time. DO NOT attempt to screen the floor until the finish has completely dried since this will cause deep scratches in the finish and will remain visible. You could also experience solvent entrapment, causing a tender topcoat, which is a cause of early wear. A complete re-sand is the alternative.

How to avoid in the future

A simple tool such as a hygrometer will tell you what the job site condition is and therefore you have the opportunity to act accordingly. DuraSeal^® recommends changing your expectation of the dry time if your application and drying conditions vary from…

• The coverage rate on the label (see Finish and Curing Parameters)
• A temperature above 70 degree F (25 C) and Relative Humidity below 50%.

Note: Dry times, either fast or slow, are affected by Temperature, Relative Humidity and Air movement, either natural (window) or forced (HVAC) PLUS coverage rate. Attention to these details improves success rates.

The Problem

Topcoat has bumps when dry.

The Cause
Bubbles

This can be the result of the finish or the floor being too cold, humidity being too high, the previous coat(s) not being dry before this last coat was applied, or overworking the finish during application. In addition, not following the coverage rate directions such as applying too heavy a coat, often lead to this condition. Most finishes cure from the top down. If the wet coat forms a skin before the air folded into it can escape, the finish forms bubbles and can not level out.

Craters

These are caused by bubbles that have released their air but the finish has then hardened to a point that it can not level out and feels rough to the touch.

Trash in the Finish

Airborne dust from heating vents and/or failure to tack efficiently, place dust particles in the finish. Also an aged, partially-used container of finish may contain skinned product which may be distributed throughout the product upon agitation.

How to fix the problem

Oil modified bubbles and craters can usually be screened and re-coated with a thin coat of finish. Waterbased finishes that have bubbled can be scraped flat but will probably require re-sanding.

How to avoid in the future

Determining the conditions at the job site and ensuring that it is feasible to apply the finish is the responsibility of professional sand and finishers. Tools such as hygrometers and moisture meters tell you what the job site conditions are so that you can act accordingly. Where possible alter the temperature, humidity and ventilation conditions to those recommended by the specific product directions. Block off all air vents, sweep, vacuum, and tack, then apply finish.

If this is not possible to do immediately, it is better to wait until you can.

The Problem

The look of the stain is uneven.

The Cause

This can be due to the sanding procedures being uneven. Uneven sanding will cause the color to look uneven. Improper wiping techniques are another reason for uneven staining.

How to fix the problem

1. If sanding procedures are the cause, then only a complete re-sanding and re-staining of the floor will fix the problem.
2. If improper wiping techniques are the reason for uneven staining, and the floor has not yet been top coated, buffing the floor with mineral spirits and steel wool (for solvent-based finishing systems only), or white synthetic pad under the buffer, will even out the color.

How to avoid in the future

Sand the floor according to NWFA standards. Ensure ALL superfluous stain is wiped from the floor.

The Problem

Topcoat is not smooth when dry.

The Cause

This can be the result of the bottom coat(s) not being dry enough to accept an additional coat. Or, a topcoat’s solvents etches (eats) into weaker or uncured bottom coats. The job site conditions and too heavy a first coat are the usual reason for these problems.

Blistering

Will sometimes occur in spots and could be caused by spotty drying of bottom coats.

Wrinkling

Will result as blisters over a large area of the floor.

Alligatoring

Very heavy wrinkling results when the topcoat etches (eats) into the bottom coat and actually lifts it from the raw wood or the stain or sealer.

How to fix the problem

Blistering and wrinkling can usually be screened and coated with a very thin coat of finish. Alligatoring requires a complete sand and re-coat.

How to avoid in the future

Determining the conditions at the job site and ensuring that it is practical to apply stains and finishes is the first duty of professional sand and finishers. Tools such as hygrometers and moisture meters tell you what the job site conditions are so that you can act accordingly. Should the conditions be borderline, it is wise to allow more time than normal to ensure the sealer, stain or finish is dry. Correct temperature, humidity and ventilation are the keys to avoiding these problems. In addition, not following the coverage rate directions such as applying too heavy a coat, often lead to this condition.

Chipping is most often caused by abuse or excessive impact beyond reasonable and customary wear. When peeling occurs, the most common causes are incompatibility of the coating system, failure to observe recoat intervals or lack of proper abrasion. Delamination can occur due to pre-existing contaminants or improper abrasion.

Please consult with your DuraSeal^® Distributor for specific advice to minimize the occurrence of these issues, and always read and follow label directions.

Color Changes/Ambering

General Comments

1. All uncoated, bare wood and ALL oil-based polyurethanes get darker in color with time. They darken less and at a slower rate, when they are exposed to light.
2. Ambering of waterbased finishes varies widely. However as a general statement waterbased finishes are more color stable than oil-based finishes and therefore amber at a slower rate.

The Problem

The look of the floor has darkened non-uniformly over time.

The Cause

Since the wood itself and, sometimes, its topcoat are darkening with time and light exposure, then any areas of the floor covered with area rugs, furniture, etc. will appear darker when uncovered. This is more pronounced if an oil modified polyurethane finish is applied instead of a non-yellowing or non-ambering waterbased finish.

How to fix the problem:

1. For an immediate remedy, completely re-sand (If applicable re-stain) and re-coat the entire floor.
2. The condition is substantially but not completely reversible with the passage of time. Removing the items that are blocking the light will allow the previously unexposed, darker areas to lighten and blend somewhat with the rest of the floor. The blend is not perfect, however, because the wood lacks the ability to “recover” fully.

How to avoid in the future

Finishing with a non-ambering topcoat will eliminate the darkening appearance contributed by the finish. Protecting the wood from the bleaching effects of sunlight is achieved only by minimizing sunlight infiltration via drapes and ultraviolet (UV) light blocking windows. UV light blockers in the finish cannot eliminate color variability problems caused by sunlight.

Note

This condition can occur on any floor but is more pronounced the lighter the color of the floor.

Scuffing often occurs due to improper maintenance or the use of harsh or improper cleaning products. Additionally, freshly applied coatings can scuff easily when put into service prior to achieving full-cure. Care should be taken in avoiding abuse of your hardwood floor. Please read and follow label directions, and use DuraSeal^® Floor Cleaner and maintenance products to maximize the lasting beauty of your hardwood floor.

The Problem

Finishes will wear.

Wood Floor Preventative Maintenance

1. The use of walk off mats at exterior entrances help to prevent sand, grit and water from being walked onto the floor. Sand, grit and water are the floor’s worst enemy.
2. Install proper floor protectors on furniture used on hardwood floors. Protectors will allow chairs to move over the floor without scuffing. Clean the protectors on a regular basis to remove any grit and sand that may have become imbedded in them.
3. Sweep on a daily basis or as needed but do not use household dust treatments as this may cause your floor to become slick or dull the finish. Vacuum regularly. Clean the hardwood floor when the household carpets are being vacuumed. Brush attachments work well on hardwood floors, but do NOT use the beater.
4. Since finishes are designed to protect the stain and face of the wood, they are not designed to protect against excessive water. Never WET-MOP a hardwood floor. Excessive water causes wood to expand, possibly damaging the flooring. Propriety hardwood floor cleaners such as the DuraSeal^® Hardwood Floor Cleaner are the industry’s recommended method for cleaning floors.
5. Keep high heel shoes in good repair. Heels that have lost or worn through their protective cap will expose the fastening nail. This will exert over 8,000 lbs. per square inch of pressure on a floor. This pressure will damage all types of wood floors.

The Problem

Worn finish.

The Cause

Any floor finish can be worn off to bare wood. This is caused by improper or no maintenance. It needs to be pointed out that the lack of walk off doormats, the use of street shoes and hard-soled slippers indoors, as well as dogs and cats with will definitely contribute to premature wear of a finish. Another reason is the lack of good quality felt furniture protector under chairs and tables.

Harsh chemicals contribute to the early deterioration of finishes. Although vinegar in water once was a viable cleaning solution, it is no longer recommended by the industry, due to its acidic value. It has been determined that prolonged use of vinegar in water as a cleaning solution actually leads to de-glossing of the finish and eventually premature wear.

How to avoid in the future

Ideally the use of entryway walk-off mats and the removal of street shoes will greatly reduce the amount of sand and grit being tracked onto your hardwood floors.

In addition, the use of finish manufacturer’s recommend floor cleaners such as the DuraSeal^® Hardwood Floor Cleaner will ensure the remove of normal dirt and dust without the introduction harsh chemicals.

DuraSeal^® offers a complete line of superior quality professional hardwood floor products such as Stains, Sealers, Polyurethanes, Waterbased Finishes, Sports Floor Coatings, Wood Fillers, Waxes, and Maintenace Products.

DuraSeal^® products are sold through a select group of professional hardwood flooring distributors in major markets throughout North America. To find a distributor in your area click here.

DuraSeal^® is exclusively formulated for site-finished hardwood floors and is sold to professional flooring contractors.

Yes. DuraSeal^® has high performance products for all your hardwood flooring needs. Click here to view our products.