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Author Topic: DTS400 severe swirl marks  (Read 819 times)

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Offline E_Aiken

  • Posts: 1
DTS400 severe swirl marks
« on: June 20, 2019, 06:00 PM »
I purchased a DTS400 earlier this year and have been struggling with sanding marks from the start with it. I'd read a few accounts of these sanders needing a break-in period before they function at their best, and in waiting for that moment, I passed the 30 day window. I'm sanding 120/180/220 (starting lower if needed, generally not) and moving slowly. Hooked up to my MIDI even at minimum suction, the sander sticks to the workpiece, yielding bad marking. Using the included dust bag, the suction is resolved, yet there are still generally swirl marks left I need to go back and clean up by hand or with my Bosch sanders (when they'll fit.)

I'm happy to accept it as user error, though I don't have problems with either of my Bosch sanders nor my cheap Ridgid. Has anyone else encountered this and found a method to eliminate it?

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Offline Peter Halle

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Re: DTS400 severe swirl marks
« Reply #1 on: June 20, 2019, 07:36 PM »
Sorry to read about your situation.  Out of curiosity do you see the swirls after sanding with the first grit?  If not, try wiping off the board between grits and see if that helps.


Offline sheperd80

  • Posts: 127
Re: DTS400 severe swirl marks
« Reply #2 on: June 21, 2019, 08:30 AM »
I have the same issue with that sander, its relegated to only sanding primer on painted projects at this point and in that capacity its decent i guess. I bought the interface pad for it and that helps a bit along with lowering the sander speed and vac suction. Its dissapointing though, this is definitely not the finishing sander i hoped it would be. It wont go anywhere near hardwood or fine furniture pieces.

The "system" dust collection aspect is the only reason i still have it, otherwise id use a much better $50 home depot sander. I still may end up doing that. I dont know how festool manages to take an age old design, do it wrong, and charge 4x as much.

Sent from my SAMSUNG-SM-G890A using Tapatalk
« Last Edit: June 21, 2019, 08:35 AM by sheperd80 »

Offline RobBob

  • Posts: 1378
Re: DTS400 severe swirl marks
« Reply #3 on: June 22, 2019, 07:33 AM »

Alex knows this sander well...

Online ScotF

  • Posts: 2651
Re: DTS400 severe swirl marks
« Reply #4 on: June 22, 2019, 11:40 AM »
Try turning suction down. You also need to move a finish sander slightly faster than a random orbit sander - lower grits will leave more of a swirl but this evens out as you go up in grits. You might need to go one farther than you normally would to get a good finish. I get great results with my DTS - but it did take practice.

Offline Sparktrician

  • Posts: 3801
Re: DTS400 severe swirl marks
« Reply #5 on: June 22, 2019, 11:43 AM »
You might want to view this video -
- Willy -

 "Remember, a chip on the shoulder is a sure sign of wood higher up." - Brigham Young

Offline Alex

  • Posts: 6054
Re: DTS400 severe swirl marks
« Reply #6 on: June 22, 2019, 11:57 AM »

Alex knows this sander well...

Not sure I can add much to this discussion, most things I sand get painted with a solid colour and swirl marks are not so much an issue there. If something does need to be absolutely perfect and swirl free I tend to go to my ETS125 because as a random orbit sander it leaves a much smoother surface.

The break in period is very important with this type of sander, you have to get through it or it won't work with full power. Not sure if that still counts for the new updated model though, it has a more powerful motor and I have not had a chance to use the new types yet.

But I have found that random orbit sanders are very prone to swirl marks as soon as there's just a tad too much of loose material on the surface. It tends to stick on the paper making it an uneven surface that leaves swirls. Keep your surface cleaning by wiping and vacuming it and change paper often.   

I have also encountered the problem OP describes of the sander getting sucked to the surface even on the lowest setting of the vac, it happens with the higher grits, even then the suction is just too much and that will leave marks. You could make a little piece of hose with holes in it to put between the sander and the standard hose, reducing suction even more.