Weird Wood Sanding…

Wendy’s Blog

Sometimes weird things appear as new marks that weren’t there before— a.k.a, mistakes in the sanding!

If your newly refinished hardwood floors have weird marks that weren’t there before, something is wrong with the sanding.

Think about your hardwood floors,the reason you wanted hardwood floor refinishing could be several reasons that you want them refinished. The finish might be tired, faded, or thin. It could be blistered or scratched perhaps. But it didn’t look weird before you got them refinished like it does now!

You hired your contractor, and they began their work. Now you see things that weren’t there originally, besides the blemishes you were trying to correct.

But now in random places you have odd looking marks, kind of like divots or dips in the hardwood that weren’t there before. (What is that?)

So now you are looking at your floors and you see a long depressed area in the wood that was never there, and it is about 4-6″ inches long, or it could be longer, like the length of a wall.  You feel it, and it is concave, below the rest of the floor. And, you see some marks like that that are shallow, and some are pretty deep. (What is that?)

Some can be long just a few inches in from the wall. That also is a drum mark where the refinisher repeatedly engages the drum while it is standing in about the same position, away from the wall.

Having a “drum mark”—which you shouldn’t have, is a rookie mistake.

A drum sander is a “work horse” in the industry. It is a very heavy machine that has a sanding belt that slides on “the drum” and does the bull work of the sanding. This machine is a beast! It weighs a ton, and must be fine tuned. If it’s out of tune it will leave “chatter marks” or lines in the floor.

drum mark or divot depression on hardwood floor
While dropping the lever to engage the drum while stationary, the drum will “drop” a 4-6″hot depression- a classic mistake by the refinisher

When it is fired up the sanding belt spins on the drum above the floor. It does not touch the floor until the refinisher engages it. When the refinisher pulls the lever the drum “drops” and now the sanding belt with the drum contacts the floor and starts the sanding.

A HUGE MISTAKE—dropping the drum before you move in a foward walking motion. This is a rookie mistake. The refinisher has to learn to begin moving, engage the drum in the direction of the grain, and lift and de-engage the drum at the end of the pass, before the machine is turned in the opposite direction.

On this particular job the drum marks were everywhere. I think I counted between 10 and 20 in this hallway alone.

Training corrects this!

When a refinisher is working with a sanding instructor or professional, they will correct this mistake for sure. In fact, they will watch and adjust the “engagement-disengagement”, and hammer it over and over again until the refinisher has a full working knowledge on how to avoid causing this “trauma” to the floor.

Weird half circles appearing against an edge of the floor are edger digs, and again a rookie mistake;

A sanding edge machine is like a wild animal. It is heavy to begin with, and then when its turned on it becomes a beast to control. The B-2 and 7 R edgers are usually run by men because they are harder to control. But without practice or experience, refinishers can often lay in to the edger on one side, creating a half moon, uneven mark, or marks.

'Edger digs', banana marks on hardwood
This landing has bad edger digs that you can see along the edge by the railing

Pictured here are a whole gang of edger marks, still visible after the re-sanding had started. With our fingers crossed we couldn’t promise that we would remove them, but sure hoped we could for the customer. Such a prominent location, this would be bad if they were permanent!

Patches of roughness, and edger marks, there are multiple things going on here.

terrible sanding and edger digs
This red oak edge looks more like plywood than hardwood, no where near what it should look like

Not going to sugar coat this, this floor is hammered in about every direction, as far as the sanding goes. Then its still a mess and continues to be a mess with the staining. In fact it didn’t look stained, it was flat out painted!

Perhaps two fatal mistakes can be seen here, in one picture

sanding staining against the grain on hardwood floor
With the grain going from left to right, look closely and you will see faint lines going from top to bottom, evidence of working against the grain.

The drum sander was run by the refinisher in every which way, the worst cardinal sin in refinishing that could be done. Then to top it off the stain was rolled on with a paint roller, from a standing position. AND, the stain was also applied across the grain.

If this is what the hardwood floors look like after refinishing, it is simply unnacceptable. The wood has been traumatized with the sanding process, no blemishes were filled, and then the stain was painted on.

To sum up the scenario, there is no room for unsupervised or inexperienced on the job training with hardwood floor refinishing.

Just diving in and getting your hands on this aggressive machinery doing very complicated and difficult work without experience or training will not yield a chance of professional results. To learn why training is important click here: Why Finishing Hardwood Floor Training Matters

Thankfully now we are able to share that we have completely restored this floor, and saved the roofers’ necks!

There are no signs of the trauma. The wood responded completely, and the floor is now flat, smoothe and gorgeous. I am sharing this so that if this kind of work is done to other floors that customers have the sense to pull the plug. I also share this to educate contractors who may think they want to do floor sanding in addition to other work.

If you decide to offer this service, hire an experienced refinisher, or go to an accredited refinishing school. There is no room doing this work for unsupervised on the job training!

We fix screwed up and ‘botched’ hardwood floor jobs. If you have any of this kind of workmanship give us a call. Hopefully we can fix it for you! Free estimates and friendly advice, you don’t have to live with messed up hardwood floors. Call 609.953.0472 or Contact Us on line.