Hardwood Floors April/May 2019

AT THE SITE

Sanding Aesthetics Causes and Cures

SANDING MARKS (CHATTER, WAVE, DISHOUT/SHELLOUT)

The process of sanding a wood floor is more than just something that can be taught through a book, video, or user manual. Sanding is an art as well as a skill. Those of us who sand floors understand our equipment in a way that is difficult to explain. Whether it’s how the machine feathers, where the machine cuts, how we clock, wheel placement, the rhythm of our step, the pitch of the motor, or just the feel of the sander over different species, every machine is unique. A perfect install can be ruined by a poor sand job, just as a perfect sand job can make a poor install look good. I think we’ve all learned from our mistakes in an e ort to become be er oor nishers. e following are many of the sanding-related irregularities that are more speci cally detailed in the most current edition of Problems, Causes, and Cures (Publication C200) available at nwfa.org .

Sanding imperfections seen as drummarks, side cuts, sanding scratches, or swirl marks, slight unintentional indentations causing ripple-likewave e ects or “bars” that run perpendicular to thewood’s grain direction on the surface of awood oor that can become visibly pronounced in direct lighting. Indentations, or waves, usually repeating undulations, visible on a site- sandedwood oor surface, most o en visible a er a nish has been applied. Dishout in the surface of individual boards or within thewood oor, resulting fromso er areas having been sanded to a lower level than harder adjacent areas.

CHATTER

WAVE

BIG MACHINE MARKS

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