I'm currently sanding some raw hard maple in preparation for staining, and I've noticed some faint swirl marks left by my Festool ETSC 125 sander. These marks can be frustrating because they sometimes show through the stain, which means I have to re-sand and start over. I'm wondering if other folks prefer finishing the final grit by hand using a sanding block instead. Also, I've been considering whether switching to a square sander like the Festool RTS 400 could help reduce these issues. What are your thoughts and experiences on this? Thanks for any advice!
2 Answers
I recommend hand sanding with the grain for your final pass. Using 400 grit might actually be overkill for staining; it can make the surface too smooth for the stain to adhere properly. Usually, sticking with a grit around 120-150 works better for me.
Hey! I've had similar issues with swirl marks before. One thing to check is whether you're using a Fe$tool dust collector. If the suction is set too high, it can pull the disc too tight against the wood, causing those swirl marks. I usually finish off with a longboard on the final grits to get a smoother surface.
Thanks for the tip! I do have it set to about 2-3. Should I lower that suction setting?

Just to clarify, I mentioned 400 because that’s the model number of my sander, not the grit I’m using. I'm targeting 120-150 for the stain.