Troubleshooting Sandpaper Scratch Marks

      Sandpaper choices and sander settings both play a role in swirl marks created by small wood slivers that stick to the sandpaper. May 27, 2014

I finally bought a Festool sander after years of using everything else. So far, I'm not quite as enthusiastic about it as all the reviews I've read on them. In fact we changed back to a Porter Cable to remove the horrible swirl marks left by the Festool.

The problem is this. The Festool paper is holding slivers of wood and scratching the surface terribly. This happens after we raise the grain. All of the small slivers just seem to stick to the paper and won't come off unless you physically remove them. Has anyone had this problem and found a remedy?

Forum Responses
(Cabinetmaking Forum)
From contributor M:
I'm not sure about the "holding slivers" part, but I had a similar experience going from PC to Festool 5" sanders: lots of swirl. The solution for me was to form my own opinions of what the different types of paper are good for. In general, I've found that rubin paper sands coarse. So if you want a P120 type finish, then sand to p150. Brilliant sands more like the 3m Stickits that I had been using on the PCs on bare hardwood, so if I'm sanding oak for stain or cherry, I'll switch to Brilliant at P120 to get rid of the swirls. Good extraction; not good on paper, nor on the heat buildup that kills the hook on the pad.

From contributor X:
Also, if you have an extractor with variable speed (like the Festool), then turn it way down for sanding. Some of the smaller sanders like the ETS125 need to be turned down too close to the slowest speed. Too much vacuum can be as bad as not enough. I have been using the Rotex 125 with 120 grit to get the defects off from the widebelt sander, then finish up with the ETS125 with 150 grit rubins. It's nice having dedicated sanders, so you don't have to change paper back and forth.

From contributor M:
Another small note: I really have no idea what sanding process you are referring to. Raising the grain seems to suggest sanding sealer, but slivers of wood suggest bare wood. I do remember once in middle school shop class being instructed to spray my little duck cut-out with water to raise the grain before sanding, but I'd never consider doing such a thing now. So what is it? And what sanders/paper are you using?

From the original questioner:
This is sanding bare wood prior to finishing. I always raise the grain by wiping the piece down with a damp sponge, let it dry and sand away the swollen fibers. It eliminates any possibility of grain raising during the finishing process, helps bring unwanted scratches to the surface, and gives you a better finish. I think your shop teacher was onto something.

At any rate, I'm using rubin paper 120, 180 grit. When you raise the grain, it brings loose fibers to the surface. When they are sanded off with the rubin paper, they become lodged in the paper, causing swirl marks. Mirka garnet paper does not do this. I will probably try some brilliant paper to see how it does.

Sanding schedule is as follows: widebelt 120 grit, ROS 120, raise grain, ROS 150, 180. This particular job is red oak.

From contributor M:
Thanks. Learn something new, or old, every day. My guess is that the brilliant will work better for you, but your problem might have something to do with the extra coarseness of the FT paper. Perhaps raising after p150 would relate better to your process with Mirka paper.

Would you like to add information to this article?
Interested in writing or submitting an article?
Have a question about this article?

Have you reviewed the related Knowledge Base areas below?
  • KnowledgeBase: Knowledge Base

  • KnowledgeBase: Cabinetmaking

  • KnowledgeBase: Cabinetmaking: General

  • KnowledgeBase: Finishing

  • KnowledgeBase: Finishing: General Wood Finishing

    Would you like to add information to this article? ... Click Here

    If you have a question regarding a Knowledge Base article, your best chance at uncovering an answer is to search the entire Knowledge Base for related articles or to post your question at the appropriate WOODWEB Forum. Before posting your message, be sure to
    review our Forum Guidelines.

    Questions entered in the Knowledge Base Article comment form will not generate responses! A list of WOODWEB Forums can be found at WOODWEB's Site Map.

    When you post your question at the Forum, be sure to include references to the Knowledge Base article that inspired your question. The more information you provide with your question, the better your chances are of receiving responses.

    Return to beginning of article.

    Refer a Friend || Read This Important Information || Site Map || Privacy Policy || Site User Agreement

    Letters, questions or comments? E-Mail us and let us know what you think. Be sure to review our Frequently Asked Questions page.

    Contact us to discuss advertising or to report problems with this site.

    To report a problem, send an e-mail to our Webmaster

    Copyright © 1996-2020 - WOODWEB ® Inc.
    All rights reserved. No part of this publication may be reproduced in any manner without permission of the Editor.
    Review WOODWEB's Copyright Policy.

    The editors, writers, and staff at WOODWEB try to promote safe practices. What is safe for one woodworker under certain conditions may not be safe for others in different circumstances. Readers should undertake the use of materials and methods discussed at WOODWEB after considerate evaluation, and at their own risk.

    WOODWEB, Inc.
    335 Bedell Road
    Montrose, PA 18801

    Contact WOODWEB

  • WOODWEB - the leading resource for professional woodworkers

      Home » Knowledge Base » Knowledge Base Article