Hey all,

I’m new to this site, but not to using Festool tools. I have two sanders that I currently use, the Rotex RO 150 and the ETS EC 125. I had the Rotex first and was happily using that beast, but wanted a more well rounded finish sander so I got the ETS EC 125. I’ve been using this sander very happily as this sander is much more enjoyable to use and so easy as well. I primarily use these sanders for making Live Edge slab tables with epoxy.  Since I’ve had both of these sanders I’ve run them both at low speed(s) #2 setting primarily. The question I have is, what is the proper or best speed that I should be running this sander for the best possible finish? Would I be better at a fast speed for low grit and slow for higher? Is there a middle of the road speed for all grits? Or am I completely off on all. Please advise as I am trying to up my game as well as turn out the best result with these high end amazing tools. I appreciate any help that anyone could give. And thank you guys in advance.

I'll always start sanding bare wood at max speed unless I'm getting some bad feedback from the tool and wood.

For epoxy and applied finishes I slow the speed down so that I'm not putting too much heat into the surface.

Probably more important than sander pad speed is the level of vacuum that the sander is seeing. You want just enough vacuum to remove the dust/grit from the surface and to keep the sanding disc clean. Too much vacuum will pull the sander against the surface making movement difficult, creating swirls, putting too much heat into the surface which is bad for everything including the pad itself and it can cause the sander to become jumpy which makes floating the sander across the surface impossible.

Here are a couple of previous threads and  to the FOG. 

https://www.festoolownersgroup.com/festool-how-to/what-speed-do-you-sand-at/

https://www.festoolownersgroup.com/festool-tools-accessories/sandingfinishing-question-gritspeeds/