Sanding marks

[Redsox_500]

I use Baltic birch a lot of projects & I use an ETS  150 but keep getting “scratch “ marks or “swirl” marks. Any idea how to eliminate these.

Thanks Steve

 

[luvmytoolz]

I use Baltic birch a lot of projects & I use an ETS  150 but keep getting “scratch “ marks or “swirl” marks. Any idea how to eliminate these.

Thanks Steve

What grit and type of sanding discs are you using?

 

[Redsox_500]

Starting off with 80 upto 400 grit, some of the sanding disc are Wurth others are from Amazon

 

[peter halle]

So many things to suggest and others will have more.

1.  Wipe off your work before you start and also between grits.
2.  Adjust your suction to pretty close to minimum - you don't want to suck your sander down into the work.
3.  Start your sander with the pad in contact with the work surface and lift it off before turning it off.
4.  Sand in patterns - go side to side and then top to bottom so to speak.  Go methodically and overlap your patterns.
5.  Use a raking light to check your progress - particularly at the end prior to applying finish.
6.  Let your sander do the work - don't apply more pressure than necessary to keep it on the surface - see #2.
7.  Check your sandpaper to make sure you don't get anything stuck on the paper which would create a lump.
8.  Check your velcro on the backing pad for debris as well as on the back of the paper.

These should start you off.

Peter

 

[Redsox_500]

Thanks Peter I’ll will try these next time I’m in the shop, appreciate it

 

[Birdhunter]

I use BB a lot and start sanding with 150, then 180, and finish with 220.

 

[bobtskutter]

I've been struggling with swirl marks on a recent project.
Rotex125, Granat P120/180, rotex mode and full speed
Sanding pine plywood has been leaving swirl marks.

I did some experimenting...
...I think I was moving the sander too slowly and the surface was heating up - it was warm to the touch.
...increasing the speed I moved the sander across the surface stopped the wood heating up and the marks disappeared.

just my experiance.
Regards
Bob

 

[festal]

80-400 on BB is a lot sanding.  you sure you need all that? 

 

[jeffinsgf]

80-400 on BB is a lot sanding.  you sure you need all that?

That's what I thought, too. Can't imagine needing to start any coarser than 120 (more like 150) and don't see much value in going beyond 220 until finish is applied.

 

[jcrowe1950]

80-400 on BB is a lot sanding.  you sure you need all that?

That's what I thought, too. Can't imagine needing to start any coarser than 120 (more like 150) and don't see much value in going beyond 220 until finish is applied.

In the context of baltic birch, I agree....it probably would be good to start at 180 and sand lightly. In terms of desired finish, IME it depends on what appearance you want and what kind of finish you use....if you use a film finish like urethane or lacquer, you can go to 220 and then sand finer between coats. If you are using a hard wax oil without accelerators....sanding to a finer finish will allow you to go from a matte finish to something more with more luster. That's probably overkill for BB in any case. As always, YMMV

 

[Michael Kellough]

I've been struggling with swirl marks on a recent project.
Rotex125, Granat P120/180, rotex mode and full speed
Sanding pine plywood has been leaving swirl marks.

I did some experimenting...
...I think I was moving the sander too slowly and the surface was heating up - it was warm to the touch.
...increasing the speed I moved the sander across the surface stopped the wood heating up and the marks disappeared.

just my experiance.
Regards
Bob

If your softwood plywood is like ours in NA then you only need 80 grit on the B-side and no coarser than 120 on the A-side.

I wouldn’t use Rotex mode on softwood unless my technique was impeccable. Rotex will cut into softwood way too easily.

 

[bobtskutter]

Thanks for the suggestion.  I'll try it out.
regards
Bob

 

[Crazyraceguy]

I've been struggling with swirl marks on a recent project.
Rotex125, Granat P120/180, rotex mode and full speed
Sanding pine plywood has been leaving swirl marks.
Bob

Bob, I seriously doubt that is your technique. Meaning that no one is going to be able to get a swirl-free finish in Rotex mode. Hardwood or soft, the pure rotary/orbital motion is more for material removal and the scratches are just part of it. Rotex mode is not for finish sanding.

 

[Geoffrey]

With the ETS 150/5, I try to stick to the 1 inch per second rate of moving the sander across the surface. I also often hold it near the plug-it connector, sometimes on top, but either way I avoid putting any weight on it. I do not think I have too many swirl mark issues this way.

 

[bobtskutter]

Hummm.....maybe I need an ETS125?

Bob

 

[jeffinsgf]

Hummm.....maybe I need an ETS125?

Bob

Maybe...but first try just shifting your Rotex into random orbit mode after you get it flat.