Many hardwood floor installation mistakes occur as a result of improper finish application. Hardwood floor contractors must be sure that they’re knowledgeable about all of the products they use on their clients’ floors.
Here are some general rules of thumb that you should always follow when applying finish to hardwood floors:
Rule 1: The manufacturer’s instructions trump everything else.
Before you even think about applying a drop of finish to a hardwood floor, you must read the manufacturer’s instructions. You have to find out everything there is to know about the proper handling of the product before you start using it.
The finish manufacturer’s instructions will tell you important information such as:
• coverage rate
• cure time
• aftercare and cleaning instructions
Your clients should also know about the finish you’ve applied to their floors. Include cleaning and maintenance instructions in your floor care guides to prevent clients from accidentally damaging the finish.
Rule 2: Allow the finish to properly cure.
If you don’t allow the finish enough time to cure in between each coat, or if the environment is not properly prepared for the curing process, you risk ending up with finish problems.
Every finish is different. Going back to Rule 1, you have to become familiar with the product’s instructions in order to know how long it will take to cure, and how to facilitate the process.
But there are four basic stages of the curing process that almost every hardwood floor finish goes through. Certain signs will tell you when it’s time to move on to the next step.
Stage 1: Set point / gel point
At this point, the finish is not dry yet. It will still be tacky to the touch, but enough liquid has evaporated from the finish so that it no longer flows and levels.
Stage 2: Dry to the touch
Dust no longer sticks to the finish because the surface is no longer tacky. At this stage, you should help out the curing process by circulating air in the room using a box fan with a timer.
Stage 3: Hardened
Once the finish has hardened, the floor can be screened and covered with another coat of finish. After the final coat has reached the hardened stage, you’ll usually turn the floors back to the care of the owners.
To give the finish additional time to cure, furniture shouldn’t be moved back into the room until five to seven days after the job is complete. Rugs should only be replaced about a month after the job is finished.
Stage 4: Fully cured
Although you can usually put the floors back into use within a week of applying the top coat of finish, the product is not fully cured yet. (That is, unless you used a UV hardwood floor finish system, which cures the floors instantly.)
The length of time it takes a finish to fully cure ranges from a few days to several months, depending on the type used. Oil-based finishes take longer to cure than water-based finishing products.
Minor imperfections in the finish still have a chance to disappear over time as the product fully cures.
Rule 3: Perform adhesion tests.
When you refinish a floor that was previously worked on by someone else, try your best to find out which products they used. Before you apply a new finish system to the floor, you should perform an adhesion test in an inconspicuous area to make sure it’s compatible with the old finish system.
It’s important to perform an adhesion test because if the floor was previously coated in oil-based finish, for example, and you try to coat it in a water-based finish, the new top coat will likely peel if you do not take some important steps in your preparation process.
Even if you’re pretty sure that the finish you plan to use is compatible, you’ll want to perform an adhesion test anyway to make sure that the new system will work. Better safe than sorry!