Sander left ripples in 100 year old floor

Q: I have a F******* drum sander. It only has one round drum, not 2. I sanded my floor by letting it pull itself forward, but it put ripples in my 100 year old maple floor. Am I supposed to pull this type of sander?

A: Any type of sanding machine is to be walked forward, then back, feathering the drum at the wall so as not to leave a gouge.

These ripples are called chatter and can be caused by a drum out of balance, bad wheels, bad pulleys or bearings causing shake in the machine.

You will now have to either grind the floor for a long time with a polisher and sand paper or start over by first sanding on a slight angle to remove the chatter. Since your machine has an issue this won’t be a good choice.