Hi All. We just had our floors resanded and finished and there seems to be consistent chatter marks across the whole floor. You can't feel them, but they are very noticable with the bit windows in the room.

There are a few pics at here - I took some darker pics and lighter pics so you can see the marks. The pics don't really show what it looks like when your standing in the room "in person".

http://www.valacom.com/floors/chatter1t.jpg
http://www.valacom.com/floors/chatter2t.jpg
http://www.valacom.com/floors/chatter3t.jpg
http://www.valacom.com/floors/chatter4t.jpg
http://www.valacom.com/floors/chatter5t.jpg
http://www.valacom.com/floors/chatter6t.jpg
http://www.valacom.com/floors/chatter7t.jpg

Can you give me any input on what should be done?

Thanks.

Yes, I see what you mean. They are not real bad but because there is a low, direct light source from the glass doors, they show maybe more than they would normally. Chatter is caused from many things but ultimately, the sanding machine was out of adjustment, either from the way the paper was loaded or something else. What kind of wood is that? It appears to be brazilian cherry with a satin oil poly finish. Overall, I think they look pretty good. If you need to have them better, they will need to be resanded, preferably with a belt style sander and an operator that knows how to sand floors without leaving chatter. Hardplating after drum sanding can remove chatter but one hopes not to leave it in the first place. I don't like to second guess another craftsman's work because there very well could be an excellant reason or cause that was beyond his ability to remedy. IMO, I'd try to live with it as it isn't real bad but it's your house and your call.

This is Australian Spotted Gum with a Swedish finish. I posted some earlier problems with the original installed that was using Traffic. The original installer did a very nice job installing, but had difficulty applying the Traffic finish. After 4 coats of traffic, the original installer as well as other contractors all agreed that that the floor needed to be taken back to the bare wood.

We really like the look of the Swedish finish much better, but the process of sanding off the Traffic resulted in creating chatter marks throughout.

The pictures don't show how significant the chatter marks are. They are conspicuous day and night.

I had the finisher make an extra pass with the large round circular sander along the walls to remove some remaining sanding marks left by the edger. The chatter does not show up on this 1.5 feet along the wall where this extra pass was made.

The chatter just showed up on the 2nd coat of finish yesterday and today on the third even worst. We used matte finish, but it still shows a lot.

Does a trio or some othe machine need to be used to solve the problem?

Please advise as I don't think we can live with this and I need to understand the best approach to take with the finisher.

Thanks.
Rob

If you cannot live with it, then it needs to be sanded again. I am not in aqreement that the Traffic finish was the cause of the chatter. There are different machines that will remove chatter from a floor BUT you need to have all the finish removed first before they are very effective. Typically, one would drum sand and edge to 100 grit, then either use a Trio, a 3 DS, or a hardplate on a buffer to remove sanding flaws. With hardplate, you still need to screen to 100 to remove swirl. If the sander/finisher doesn't know these techniques, I'd say you got the wrong guy.

Thanks very much for the reply. I don't see how removing the traffic could have caused the problem either. It just happened during that process. There was no chatter before this go around.

Will see what happens today when the finisher comes back out.

Thanks again.

Good Grief Rob, you've really been through it on these floors. What I don't understand is how the chatter became more visible with each coat. Most sweedish finishes I've seen talk about a 2 coat system yet they gave 3. Hope they didn't magnify thier own problem in offering the 3rd coat??

Do you have can lights? Those little beauties have set the finishing world back about 15 years. They've got a real way of amplifying what could usually been considdered a slight issue.

Seems like this will be the 4th resand on your floor isn't it? Maybe the first guy should sand the bugger then the second guy should come in and apply the finnish ... maybe they can form a genuinely good service if they get together in business. The sanding/prep was great the first time around but the guy didn't know how to run a mop! Now the second guy gave a beatiful finish over a chattered floor ... SHEEESH!

I'm hurtin for ya!

Good Luck,

At this point I dont know what to tell ya, you have had a hell of a time with this project. The chatter is not going to improve without sanding it back down to the bare wood its real hard to tell from the photos how evident it is throughout the entire floor ( i would imagine its everywhere but as you know certain lighting can highlight the machine marks.)

William - good grief is right!. Actually just grief.

Your right in that the orginal guy did great prep work and was not able to put an acceptible finish on.

This guy does not do as good of prep work, but is better at finishing. If they got together, they'd do really well.

Although we have can lights, the chatter is most evident during the day when the light is at a lower angle. And the contractor agrees that it is bad.

Current guy works for a large company and he maintains that he's done 3 floors since ours and did not have chatter. The chatter appeared after the second finish coat and was very noticable. He did not say anything so, I thougnt maybe the screening would take it out and then on the third it got worst. Wrong.

Thinking that maybe the process of sanding off the very hard traffic finish caused the machine to have little surges, etc. I have read that a machine might leave chatter if the power is not right and I wonder if the fact that this guy is direct wired into my breaker box @220 has something to do with it. He's not using a breaker, just large clips. Thinking out loud.

CURRENT STATUS:
This is the third sanding. Everything is now back down to wood. They sanded at about a 15-20 degree angle and are now using a yellow machine with 4 vibrating 6" pads on the bottom.

It looks to me that this machine leaves the typical "little" swirl marks that a hand vibrating sander leaves. I aked him if he was going to do a final sanding with the belt sander to get them out and he said "no need". This and the buffer will do fine.

I think he's asking for more problems and I think he's counting on a matte finish to hide any marks. Yes - we've gone to matte now to make life easier. I'm going to insist that they do a final sanding with the grain, then buff and finish.

Any input? Let me know what process you guys would take.

Thanks,
Rob

If you want to piss off a pro, just tell them how to do their job. I suggest you let him be. If he screens the floor, there should be no little swirls from that multi-disc sander. As long as he uses a fine enough grit, there should not be glaring sanding marks. The one thing I would request from the business owner, is that he and you inspect the sanding job after it has been completed and BEFORE any sealer/stain or finish is applied. That way, any correction can be made easily. At that time, you can point out any concerns about the sanding and the owner of the company can be assured his men did the job correctly. This will save you lots of grief.

Gary - Thanks. I don't want to piss them off. They are good guys and we get along real well so we can have some pretty frank discussions.

We've been through the ringer on this and my goal is simply to make sure that the floor is ready before any sealer/finish is put on.

I will make sure we do the walk through. After belt sanding the finish off at an angle, they used this multi disc (quad) sander today. Then they used the buffer with 120 grit sand paper.

Lots of angle sanding marks still in the floor. I guess they will have to go back to quad tomorrow and work on the angle marks more.

I just wonder if they should have gone (or should go) with the grain with the belt sander at some point to ensure the angle sanding marks are removed.

Oh, well. Don't care how it's done as long as no sanding marks remain before the finish goes on.

If anybody has any other input, please fire away. I'm going to live in a tent if it doesn't get finished this time.

I don't know about the guys you hired. If I had sanded this floor, I ALWAYS sand the first couple of passes at a 7 to 35 degree angle and sand with the grain on my final pass with the BELT sander. Then I follow that up with hardplate, multi-dics, buffer, etc. This has been STANDARD sanding procedure (with a few twists) for 10 years or more. Sounds as if these guys are expecting the mutli disc to remove the angled sanding. WRONG! Not going to happen. Just make sure they don't apply any finish until the floor is sanding mark free.

Current status:

After sanding the floor at about a 30 degree angle to take the chatter marks off, they have sanded for about a day with a yellow machine with 4 orbital sanders on the bottom. I think its a multidisc of some type?

Yellow machine was obviously flatening the floor and taking out any remaining chatter but was a bit time consuming.

After once over with the yellow multi, they decided to give it a shot at belt sanding 80 grid with the grain.

Chatter marks came back in all the sanded areas. Wolfgang got about 1/3 done and decided to stop. He insists that he is not getting chatter at other sites with this machine. He indicated that he never had to resand a floor in 25 years because of this.

He left today to go get a hard plate sander and return Sat. morning. Plan is to hardplate the whole floor, then multi disc sand, then buff.

My guess is that either the chatter was still in the floor and it came back out, or his machine does not work well on this hard wood. Can hard wood (spotted gum) vs. soft wood make a difference in machine performance?

stumped in FL

Here is the latest.

After getting the chatter marks again yesterday, Wolf brought a hard plate and cut the floor with 40 grid hard plate. Chatter is now gone again. Then he cut it with 40 grit multidisk sander and 120 screen.

Hardplate swirls/multidisk swirls pretty deep remain in the floor. Wolf then went to a 60 grit multidisk cut, then 80 grit multidisk cut, then 150 screen very slowly. Swirl marks gone, the one room we focused on looks good.

Then he thought that maybe just skip the 60 and 80 grit multidisk and tried other rooms with just the 150 screen. Marks did not come out.

Back to the same successful approach we used on the one room, 60 grit multi, 80 grit multi, then 150 screen very slowly.

Looks like we may be able to put a coat of finish on it on Sunday.

Sounds to me that some of his problems have been in skipping some in-between grits. This species also sounds like it will tell on anyone who attemts that kind of short cut.

In essense he has sanded the job 2 more times in all of this yet thankfully without applying finish untill it was right.

Those chatters could be resulting from species vs. machine issues. But that would be a first for me, then again I have never sanded the spotted gum. Is there a chance that this floor was installed in the same direction of the floor joists beneath? Maybe some kind of harmonic vibration going on here ... puzzled ... me too.

As long as this mystery gets put to bed soon, the happier you will be.

Take care Rob,

Will

Will - In probably 400 sq. ft. of area the joists run parallel to the flooring and the other 1600 sq. ft. run perp. The floor was orignally built for tile and has two layers of 3/4 t&G. Not much moves or vibrates. The orignal finisher attained a real flat floor with no chatter.

On the resand is when the chatter showed.

The first coat went on beautifully. Only issue is that so much sanding compacted saw dust into a lot of cracks and it didn't come out on vacuming. After the first coat, lots of real light sawdust in the cracks between medium dark planks.

After the floor dried yesterday I spent 6 hours with my wife scraping out the sawdust in the cracks with a razor then vacuming it, then putting filler in and immed. wiping the filler off of the top of the floor.

Did all 2000 sq. ft. My back was aching last night at 1am.

Wolfgang the finisher showed up at 7am and was not to thrilled but was a good sport and understood. He said the sawdust lines would darken with time, but I'm not going to walk around on a new floor with dust stripes in it and wait for them to darken to my liking.

Me and a laborer wiped down the remaining filler haze and Wolf screened with 220. He's applying second coat of finish now and I'm real happy that I removed all of the sawdust in the cracks now that I see the finish going on with no light lines.

The swedish IMO looks very rich compared to the Traffic that was on it.

Thanks again for everybody's input and I'll post final once more after the final coat is on and the job is finally finished.

We started just before Thanksgiving.

Rob