Following the directions in our floor
sanding guide and video should prevent problems preparing
your hardwood floor for refinishing. Unfortunately, a
few problems you might experience may not become evident
until you apply the first coat of finish. By screening
the floor prior to applying the finish, you can normally
eliminate the problems before they require corrective
action. However, minor problems can be easily fixed. If
the affected area is small and localized, you should consider
hand sanding, followed by screening.
Here are a few of the common problems
the “do-it-yourselfer” might encounter.
1. Chatter marks - Chatter marks
are consistent imperfections, between ¼” to 1” apart.
These marks are related to the drum sanding operations
and can be removed screening the area, using 100 grit
mesh screen. Screening the entire floor will help to make
the surface texture of the floor consistent from the edge
to the center. It also removes or reduces chatter.
2. Waves - Waves are similar to
chatter marks, but generally are 1” to 6” apart. Waves
normally appear in the direction of sanding and will become
worse with repeated passes. Minor waving can be correct
by re-screening with 100 grit mesh screen. To correct
severe waving, you will need to drum (or belt) sand the
floor diagonally at a 45 angle. Be sure to move the sander
slowly over the affected area. Another possible solution
is to use a hard plate sander with 80 or 100 grit paper.
3. Swirl marks - Swirl marks occur
during edge sanding. To prevent swirl marks avoid “bearing
down” on the edger to achieve faster cutting. The best
technique for removing swirl marks is hand sanding the
affected area. Severe swirling, sometimes called “dishing”
may require scraping; followed by hand sanding.
4. Picture framing - Floor preparation
normally requires drum sanding, edging, scraping and hand
sanding. The key to achieve professional results is to
blend the areas receiving different preparation techniques,
so that you achieve a more uniform finish. Picture framing
is the difference in color and texture that becomes visible
when finish is applied to a prepared hardwood floor. (The
wood absorbing the finish at different rates causes it.)
The best way to prevent “picture framing” is to screen
the entire floor using 120 grit mesh screen, prior to
applying any finish. Screening between coats of finish
will also improve color and luster consistency.
5. Sandpaper not removing old finish
- If your floor has been painted, has a heavy finish or
has is coated with mastic, you might experience “loading”.
Loading is simply clogging of the grit, resulting in loss
of cutting capability. This is a problem that the professional
floor sander also encounters. If the sand paper no longer
seems to be removing the old finish, check to see if the
paper is clogged with old finish. If the paper is clogged,
replace the paper. If you continue to experience problems,
consider using coarser grit. Remember, you should use
the finest grit possible to get the job done. We normally
recommend starting with 24 grit, if you are removing old
coatings.
Should you experience problems while refinishing
your floor, these troubleshooting tips will help. If you
need additional assistance, please call or submit your
question
to Dr. Sand. We will be happy to assist you achieve
superior results.
