Sanding Schedule to Avoid Swirl Marks

To remove mechanical sanding marks, you have to hand sand at the end. Here's more. March 26, 2013

Question
Can anyone suggest a sanding schedule for sanding soft maple that will be stained with SW wiping stain? I went to 180, but seem to be getting a few swirl marks from the sander. Can I go as high as 240? The sander that I’m using is the Festool ets125.

Forum Responses
(Finishing Forum)
From contributor M:
First of all I try to avoid staining maple at all. It never seems to take the stain especially if it is dark. However I also use a Festool and I use a 100 grit to start and then a 150 to finish. I don't go any farther if it will be stained. The finer the grit the less the stain will take. The 100 sand is thorough the 150 sand is with little too no pressure. In my experience swirl marks often come from over sanding. Really all sanding is making nothing but lots of swirl marks. The trick is to get them consistent so that you can't see them.



From contributor C:
Festool is a good sander. Try slowing down your sanding time and be sure you’re sanding with fresh paper.


From contributor R:
Remember, sanding is just replacing one scratch pattern with another. If only going from 100 to 150, try 120 in between. Only sand enough to remove the previous scratch pattern, and then move on. Even RO’s leave discernible swirls so finish by hand if you don't want any.


From contributor F:
You can sand to whatever grit you want, but swirl marks will always be there, they just get gradually lighter and lighter. Or you could sand to say 150 with the ROS and finish up with hand sanding. Depends on what level of quality you’re trying to achieve. Personally I would never send anything decent out the door without hand sanding.


From the original questioner:
Has anyone who’s ever used the Festool linear sander (I believe it's supposed to imitate hand sanding in a linear fashion) had any problems?


From contributor R:
We use Festool sanders but always hand sand, even on large jobs. What are you afraid of?


From contributor B:
Ideas to reduce swirl marks: work the grits in sequence (don't skip a grit), insure that your dust collection is working properly, and make sure that all of the stray grit from the previous sand is removed before going on to the next grit. Best practices include vacuuming or wiping off both your workpiece, as well as the sander and back-up pad between each grit. Lastly, include a final hand sanding step in the same grit that you finished your disc sanding.


From the original questioner:
I’m not really afraid of anything, just looking to do it quickly and efficiently. Thanks for the insight - looks like I have to hand sand.


From contributor R:
Don't fight it. There's quite a bit to setting scratch patterns by hand.


From contributor O:
If after you have sanded you have swirl marks, you are not done sanding – it’s that simple. Why are you locked into SW wiping stain? Why not achieve your final color with a toner, a dye stain, or a combination mixed in with your topcoat.


From contributor W:
My "go to" sander is a Festool ETS 150/5 with a 3/16" orbit. If I am staining oak or maple dark I finish up with a Dynabrade RO with a 3/32" orbit with 150x. Like others have said, I wipe down before stain with thinner and use a strong raking light to see missed areas.


From the original questioner:
I haven't got into spring toners. I would welcome some advice on how to go about doing it. Also I will be applying thinner prior to staining. Is there anything I can do to affect the wood as to make it less likely to take the stain evenly.


From the original questioner:
Well I finished the job. I sanded up to 220 with my Festool sanders, hand sanded with grain, washcoated, stained, let it sit for 24hrs, sprayed on the cat lacquer, and sanded between four coats. They look like glass, not sanding marks, and they are smooth.


From contributor F:
If you finish for a living you’re a professional finisher, if not, you’re not. All the rest is semantics and nonsense and doesn't really matter anyway. You can be a pro finisher and do good work, or your work can be crap. I had a pro with a nice shop, large walk-in booth (all high end gear), and many years of experience do several projects for me and none of them were up to my standards - and I'm just a cabinet guy!