Festool sander stroke; 3mm vs 5mm?

[kooshball]

I am looking at buying a festool ETS EC 150 EQ and am not sure how to decide between the 3mm or 5mm stroke. 90% of its use will be for sanding furniture in preparation for finishing. I do not anticipate using it for polishing or buffing finishes. I work with many species of wood so being able to handle soft woods and hard woods is important.

That said, which orbit size would be most appropriate for my intended uses?

Thx!

 

[Rwe2156]

For finishing 3mm.

 

[Bill Clemmons]

Both! I use mine the same as you are intending, and for most of my sanding I use the 5mm (rough) setting. I typically wet the wood to raise the grain prior to the final sanding. On the final sanding, after wetting, I switch to the 3mm (smooth) setting with a finer grit paper.

 

[Ricksmi]

I prefer the 3mm for finish sanding and follow the method Bill uses of wetting the wood to raise the grain and then a final sand prior to finish.

 

[JimD]

I do not own a Festool sander but my favorite is a now out of date Bosch DEVS 1250, a bit like the Rotex of Festool and it has a 5mm stroke. Normally I use it for all my sanding including final sanding with 220 grit prior to finish application. It has a 5mm stroke. I cannot see any scratches it is leaving nor can anybody else who has examined my projects. I often use it's aggressive mode early with 100 grit and sometimes 80 grit but I rarely use that sanding mode for 150 or 220 grit paper. The aggressive mode (Bosch calls it turbo, I believe) would leave visible scratches but I always finish sanding with that grit in random orbit mode. I use this sander because it reduces my sanding time both because of the 5mm stroke and the available "turbo" mode.

 

[Wiley's Woodworks]

Summing up all the above responses, the 5mm stroke with lower grits will do better at removing wood, the 3mm stroke with higher grits will work best for final sanding before applying finish. I usually stop at 220 grit for finishing, and usually follow that with hand sanding with a block and a slightly used piece of 220. Think of this last step as a skim coat. With thinner finishes I may microscopically scratch early coats by hand with 320. So far I have not found it necessary to wet the wood and raise the grain with any species of wood.

I have a DeWalt vibrating square pad sander that I use with 220 grit for my final sanding. You can cut down on sanding swirl marks by making sure you don't press down on the sander (just rely on the sander's weight) and move it across the surface faster than your early sanding steps.

 

[kooshball]

I do not own a Festool sander but my favorite is a now out of date Bosch DEVS 1250, a bit like the Rotex of Festool and it has a 5mm stroke. Normally I use it for all my sanding including final sanding with 220 grit prior to finish application. It has a 5mm stroke. I cannot see any scratches it is leaving nor can anybody else who has examined my projects. I often use it's aggressive mode early with 100 grit and sometimes 80 grit but I rarely use that sanding mode for 150 or 220 grit paper. The aggressive mode (Bosch calls it turbo, I believe) would leave visible scratches but I always finish sanding with that grit in random orbit mode. I use this sander because it reduces my sanding time both because of the 5mm stroke and the available "turbo" mode.

Funny you mention that 1250 devs; I actually have one machine too which I completely forgot about since I have never used it for fine work!

 

[Darl Bundren]

Funny you mention that 1250 devs; I actually have one machine too which I completely forgot about since I have never used it for fine work!

You might try the Bosch sander in a fine finishing application and see if it works out for you and all you'd be out is the cost of the paper if it doesn't. I have one and typically use it for removing lots of material in the destroyer mode. I've used it to rough out shapes and remove finishes quickly, and it's great for that.

I also have a Festool ETS 150/3 (an older one, I think--I just looked and the new ones seem a little different?) that's my go-to if sanding to final grit is all I need. I prefer the ergonomics and operation of the Festool--I can shift my grip from holding it from the top to holding the handle to (if the wood's not squirrely and pulling) holding it at the junction where the hose connects to the port. In all three positions, the pad stays flat on the work without canting or tipping. Seems like the vibration is lower, too, and the more I use it, the better the amortization rate of the initial purchase cost . It removes less material than the Bosch, but for final sanding, that's fine by me.

Good luck with it!

 

[Douglas Robinson]

If you live near a Klingspor go visit them. The advice here is good, and the staff at Klingspor can demonstrate how they use them and make recommendations based on your intended use.

 

[JimD]

I find the Bosch DEVS 1250 works well for fine work but it does tend to remove more wood on the side where the motor is. I often use it one handed and that probably affects how well it is supported. But as long as you are aware of the tendency I do not find it hard to make sure I move it around so I do not get a thin side on the project.

I've owned many sanders over the years and still have a battery powered Milwaukee finish sander and an old Rockwell pad sander and a 3x21 belt sander. I occasionally use the Milwaukee but the others just sit in their drawer almost all the time. The Bosch is so much faster I just use it. Especially with 40 grit in turbo mode (stripping paint off my house) it is a handfull but it produces good results.