# Most efficient way to sand 1/4" roundover



## mbira (May 15, 2014)

Hi guys. I build marimbas (large wooden xylophones). The keys are usually made of Padauk and I always use a 1/4" roundover bit on the edges. I recently acquired a small Jet drum sander (the 1020) and I have 220 grit paper on that. I've read other places that people have trouble with that grit, but it seems to work for me. Anyway, I have all the faces except the endgrain down to that 220 drum and then do the roundover and cut the arch for tuning the key on the bandsaw and then fine tune with a belt sander. 

After I'm at that point, I use a RO to finish sand (to 220). A lot of my time is spent cleaning up that end grain for the small router bit lines and getting the curve of the roundover feeling really good. 

Finally my question-can anyone recommend a machine or some way to more quickly do that part of the sanding? I'm looking at edge sanders, but they can't do that roundover. Any other ideas? 

Here's a picture from one of my marimbas-sorry the pic doesn't better show the arch underneath:










To give you an idea, this week, I had to sand 80 keys. It took 3 days. I'd really love to speed up that bottleneck! 

Thanks for any tips!


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## epicfail48 (Mar 27, 2014)

If poor quality on the roundovers is your issue, I'd spend some time upgrading the router bit and playing with speed and the like. A sufficiently sharp bit at the right speed should, SHOULD, produce an already satisfactory finish. As far as a machine goes, maybe one of those air bladder drum sander thingies


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## mbira (May 15, 2014)

Thanks for your reply. The round over itself is good, it's just that transition from the round over to the 220 drum sanded part needs to be touched up-especially on the end grain. These keys are touched often and they need to deal real good on the curve.

That's not to say that my router and table couldn't be better-I'm sure it could! I'm definitely due for an upgrade there!


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## TimPa (Jan 27, 2010)

since you have a very consistent profile, i wold take one of the flap sanders and cut it to your profile, then mount it in a table that the piece could ride on.


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## Steve Neul (Sep 2, 2011)

I don't know if there is an actual machine to do this or not. I think a porter cable speedblock sander would do a better job for this than your random orbital sander. The pad on a orbital sander is too hard to sand a radius. It has a tendency to make flat spots on the edges where the speedblock sander has a soft felt pad.


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## epicfail48 (Mar 27, 2014)

mbira said:


> Thanks for your reply. The round over itself is good, it's just that transition from the round over to the 220 drum sanded part needs to be touched up-especially on the end grain. These keys are touched often and they need to deal real good on the curve.
> 
> That's not to say that my router and table couldn't be better-I'm sure it could! I'm definitely due for an upgrade there!


my bad, guess I didn't read close enough. In that case, I think an air bladder sander would be your best bet, something like this:
http://www.grizzly.com/products/4-x-1-1-8-Hand-Held-Pneumatic-Drum-Sanders/H2881

That one actually chucks into a drill, but you can find independent bench to models. There's an air bladder inside the sanding drum, inflate to the right level and it'll conform to a shape


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