Varnish can help keep your wood floors looking great. When applied properly, it can also add extra protection.
Step 1 - Preparing the Floor
Remove all furniture from the room, including any rugs. Use a vacuum to clean any dust, dirt, and pet hair. This debris can reduce the effectiveness of the sandpaper.
Step 2 - Sand the Floor
You must apply varnish to bare wood. Use different grits of sandpaper to sand off the existing finish, beginning with a coarser 80 or 100 grit until you see bare wood, and finish sanding with 120 grit paper or even 150 grit if you want a finer surface. For smaller floors, this can be done by hand or using a belt sander. If you are working in a large room, you may need to use a drum sander. You can rent one of these machines from nearly any tool rental shop.
Step 3 - Repair any Marks
Look over your floor carefully and find any cracks or dents. Fill them with wood filler, and wear latex gloves while you smooth the substance with a putty knife and your fingers.
Step 4 - Clean the Surface
Sweep the dust from the floor. Vacuum the floor to remove any trace elements of dust. Use the hose attachment to vacuum the walls and ceiling as well. This is to prevent dust from collecting on the wet varnish.
Use a damp mop to finish cleaning the floor surface before proceeding. It is important to note that the mop can not be too wet. If it is wet, you may have to allow the floor to dry for several days before you can apply the varnish.
Step 5 - Apply the Varnish
Use your brush to apply the new oil-based varnish to the floor. Apply in sections that are no larger than 4 to 5 square feet. When making the strokes, try to follow the wood grain. This will ensure that the varnish looks natural.
Step 6 - Add a Second Coat
Allow the new varnish to set for 24 to 36 hours. The length of time required for this depends on the climate. Apply a second coat to the floor using the same technique. It may also be necessary to apply a third or even a fourth coat. Three coats is quite common.
When finished with the second coat, allow it to dry for another 24 to 36 hours. If the color has set well, you will not need a third coat.
Do not walk on the floor for at least 24 hours once the job has been completed.