Hardwood Floors April/May 2024

VIEWING SAND JOB COMPLEXION If there were no goal for a clean complexion in our wood floor surfaces, there would be no need for any sanding beyond what initially gets the surface flat. Given that up to 70 percent of the investment of time and materials in total sanding and screening is devoted to these processes, it’s a sure bet that sand job complexion is taken quite seriously. Finish sanding is an upward progression of finer and finer sanding grits used upon the wood floor surface until it is ready for finishing. Judging the floor’s sand job complexion is all about whether the sand job succeeded in a sort of “leave no trace behind” campaign in regards to any vestiges of the sanding process left behind that interferes with that expression. Sand job complexion flaws come in a number of forms, including bar-like marks transecting the boards. These marks clearly are not a natural feature found in the wood; they are merely a function of scratch pattern. Picking out these features as opposed to those of the topographical sort differ in a couple of ways: Reflected light, in many cases, is not utilized in picking these features out. In fact the glare only will make them harder to see – especially when there is a finish on it. However, there are some cases where the visible bars are seen best in the glare of the raw wood. A little practice is all it takes to know what’s in the glare: surface disruption “chatter” or a “chattered” scratch pattern. When there is a presence of scratch pattern chatter upon the floor, you usually can kneel down to that floor’s surface, place your hands around a section, and still see it. Conversely, if you were to try the same test with topographical chatter, the feature often disappears. THE USUAL SUSPECTS: SAND JOB TOPOGRAPHY ISSUES BIG MACHINE Any time someone shows me photos that clearly depict chatter as topographical issues (commonly called “waves” or “ripples”), I will never advise to NOT have the machine looked at. Out of-round wheels, arthritic suspensions, drum pressure, and suspension issues all heavily factor into how flat any floor’s sand job topography is going to appear when the floor is finished. We call this the “Ride of the Machine.” If you shut down the motor, roll the machine up and down the floor while raising and lowering the drum, you are working the Ride of the Machine.