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View Full Version : Anyone thickness with a ROS? Mirka Deros and Ukuleles



Matt Lau
09-04-2019, 5:47 PM
Hi everyone,

I don't have a wide belt sander, but I do have a Mirka Deros.
I have to remove about 1 mm from some Koa for ukuleles.

Has anyone used a random orbital sander to thickness thin sheets of wood?

I've been to quite a few pro-luthiers, and the vast majority use wide belt sanders.
One person (who's wide belt sander doesn't have space) uses his drill press with a machined sanding disk.

Mark Bolton
09-04-2019, 6:46 PM
How would it ever be consistent and remotely efficient?

Edward Dyas
09-04-2019, 7:16 PM
No more thickness than that probably a normal sanding would remove 1mm.

Leo Graywacz
09-04-2019, 8:19 PM
Get some 40 grit Mirka HD paper and you'll make some good progress. Just remember you'll need to go through 80, 120 and 150 to get a nice surface for finishing when you take in account of your final thickness.

Richard Coers
09-04-2019, 9:20 PM
I'd build a thicknessing system like folks do on big natural edge slabs, and use a router to take off the 1mm. .04" is a lot to even begin to take off evenly over an entire board with a random orbit.

Bradley Gray
09-04-2019, 9:26 PM
I f you use your sander for this be sure and mark the target depth on the edge. The rim thickness is effects flex more than the middle.

Derek Cohen
09-05-2019, 8:57 AM
I would suggest - in the absence of a planer - that you use a hand plane to remove 1mm. A ROS? Never.

Regards from Perth

Derek

Mark Bolton
09-05-2019, 2:45 PM
No more thickness than that probably a normal sanding would remove 1mm.

My gosh. 1mm would take forever to cut off with any ROS we have. What are you sanding with? An angle grinder? 15 thou would be a mile to come down starting even with 100 grit through 150. And it would never be flat.

Zachary Hoyt
09-05-2019, 3:45 PM
I use an angle grinder with a Kutzall disc to rough carve fiddle and mandolin soundboards and backs, it takes the material off fast but leaves a very bumpy surface. I use the ROS to clean these up somewhat, but I wouldn't want to try to make a really flat surface with the ROS. I use a drum sander now to thickness wood for the kind of job you're describing, but I used to run it through a planer and hope for not too much tearout. With koa's value I would think you'd want to be careful not to spoil it, so I would try to find someone with a drum sander in your area. It would just take a couple of minutes on a drum sander and you'd have very good uniformity, no tearout and no snipe.
Zach

Carl Beckett
09-06-2019, 10:24 AM
I would suggest - in the absence of a planer - that you use a hand plane to remove 1mm. A ROS? Never.

Regards from Perth

Derek

+1 I would hand plane it