rotary polisher

[Kevin Jenness]

I am looking for a more effective power sander for turning. I have been using a variety of tools including a Makita electric die grinder, an electric Sioux close quarter drill, a Grex random orbit air sander and occasionally my Festool EC125 random orbit sander. The 5" Festool works fairly well on the outside of bowls with a foam interface pad but I would like a better solution for driving 2" discs on interiors. The Makita is fast, almost too fast at 7,000 rpm minimum and not super easy to control with its long straight shaft. The Grex is the most comfortable and maneuverable, great for finishing and hiding rotary scratches but not very aggressive and an air hog. I reserve it for 320# and above.

The Sioux is good ergonomically, easy to control and I can use it in one hand while rotating the lathe handwheel with the other, but it tops out at 1,300 rpm. Sioux has discontinued the 2,500 rpm 8005 unfortunately. I am currently looking at a mini rotary polisher, specifically the right angle Flex PE8 which can goes from 1,300 to 3,900 rpm, has a standard 5/8"-11 shaft and can be used with shaft extenders and 1" - 3" hook & loop backing pads.https://www.autogeek.net/flex-pe8-compact-rotary-polisher.html Aside from the two-handed grip, what's not to like? Have any of you used a tool like this for bowl sanding?

Further search shows variable speed angle grinders with a low speed of around 4k rpm, but they all seem to be heavier than the 4 lb. Flex. Ideally I would have a light, reasonably powerful right angle or close quarter die grinder with a top speed around 4-5 k rpm. I'd be fine with an air tool, but the ones I have seen run much faster. Grex has a small disc sander much like the random orbit one I have with a free speed of 15k rpm. The form factor is perfect, but I am not sure if it will be aggressive enough or slow enough for my purposes. Again, any experience to share? Thanks.

[Reed Gray]

Sanding the inside, kind of like turning the inside is more difficult. I use the 3 3/8 inch discs from VinceswoodNwonders. A 3 inch disc has more than double the surface area when compared to a 2 inch disc. Also, slow speed works better for sanding. With high speeds, the abrasives don't really get a chance to dig in and cut. I never have my trigger pulled more than half way. Added benefit of this is that your drill lasts a lot longer with the slower speeds. I have 3 or 4 of the Sioux/Milwaukee angle drills. Firm interface pads up to 180 or 220, then medium up to 400. If I go over 400, then I go to the soft ones.

robo hippy

[John K Jordan]

... I'd be fine with an air tool, but the ones I have seen run much faster. Grex has a small disc sander much like the random orbit one I have with a free speed of 15k rpm. The form factor is perfect, but I am not sure if it will be aggressive enough or slow enough for my purposes. Again, any experience to share? Thanks.

I have a different philosophy about power sanding with rotating disks. I simply haven’t done it for years. I don’t like the clouds of dust, the way power sanding can eat away at softer areas in the woods. and the way it can soften fine detail. I do effectively use the Grex and another pneumatic ROS on flat and curved surfaces but only at very slow speeds. I rarely need coarse sandpaper, usually starting with 320 grit or finer. At demos I show one piece touched only by 600 grit.

I've demoed and written about this many times and included pictures and instructions so I won’t repeat everything here but the basic steps:
- Turn to shape and make careful, gentle finish cuts with sharp tools. No chipout allowed.
- Smooth away toolmarks with appropriate negative rake scrapers, inside and outside.
- Turn off the lathe and remove NRS marks with hand scrapers. For this I usually mount the piece in a carving and finishing stand.
- While off the lathe sand by hand and/or with very gentle (low speed) ROS with fine paper; usually 600 grit is sufficient.
- Apply finish. Done.
Other well-experienced turners have examined and approved the quality of the results.

This method actually requires only three things - expertise in fine tool control, appropriately shaped and sharpened NRS tools, and appropriately shaped and sharpened hand scrapers, usually cabinet scrapers ground into various curves. A significant help is the carving/finishing stand which positions the work at a comfortable height and under good lighting. I use the one from Best Wood Tools.

After developing this method I would give up woodturning rather than go back to the old way with power sanding, on pieces large oe small. The result is better and often quicker. Note: I turn mostly dry wood. JKJ

[Kevin Jenness]

I wound up buying a Milwaukee cordless sander/polisher kit. 12 V with a 1.5 and a 3 amp hour battery. The kit came with some buffing pads and a roloc holder which I use with the twist-on backup pads from woodturner's wonders. The sander has two speed ranges, 0-2800 and 0-8300 rpm. The upper range is a little hard on the pads and you have to keep moving to avoid divots but it really melts away material. The low range is more easily controlled and twice as fast as my old Sioux drill. The unit is light and compact. It really could use a trigger lock, which I jury-rigged by drilling through the case and trigger and inserting a siding nail. All in all a nice tool. Until I reach John K's level of expertise I will be giving it a workout.477736

[Jeffrey J Smith]

I hope this doesn't sound snarky, but...I've found that sanding at low lathe speeds and low pad speeds gets the job done just as quickly and allows the discs to last longer in the process. I use a cheap, variable speed close-quarters drill from HF to sand. Going slower allows it to last longer, too. If there's a need to spend time sanding to get rid of deep tool marks or refine the shape of the turning, I've found its better to go back and try to use a little better tool control (or a freshly sharpened tool) to start at a better place with the sandpaper.
Once in a while, depending on the wood, I'll need to start at 80 grit, but usually its 120 or 180. Going back to get a better surface forces me to work on tool control and make certain my gouge is sharp. I usually finish sand higher grits (320 or 400) by hand, with the grain for the best surface.

[Kevin Jenness]

I don't find it snarky. Better tool control is absolutely the goal, and like you I strive to get as clean a surface off the tools as possible. When I get to sanding though I want to remove material where necessary and polish out the scratches of each successive grit as quickly as possible. As a cabinetmaker I have spent more of my working life sanding than bears thinking about, and I like to make it as quick and easy as can be.

I hand sand with the lathe turning at moderate speed where necessary, typically in corners where a power sander will destroy the detail. Sometimes I will use a hand-held scraper with the lathe off. I don't power sand much with the lathe running as it removes more material where it is not needed. I use the rotary disc for lower grits, rarely below 120, and a random orbit sander above 220.

I'm not worried about using up abrasives or wearing out my sanders - as long as they are not getting too hot the faster they work the better. I've had my Sioux drill for 30 years and it's still going strong, but the Milwaukee is an improvement in my book.

For reference, the rim of a 2" disc at 2800 rpm is running at a bit over 1400 ft/minute, about the same as my hand-held belt sander. The belts, of course, can dissipate the heat better but I don't have a problem with overheating as long as the discs are sharp and cutting freely and kept moving over the surface.

[Neil Strong]

I have found that fast with a very light touch works just as well as slow in the lower grits.

Like in turning, let the wood come to the grit.

I do slow down the lathe for the finer grits. Friction heat is the issue with those finer grits.

I made up my own power sander many years ago that is reversible with a flexible shaft. I don't hold the power unit, just the light flexible shaft. This reduces the stress on my back and neck. You can also add a 90deg attachment to sand inside deeper narrow necked hollow forms, where the Makita style power tool won't go.

It's hard to judge how much pressure you are applying if you are also wrangling the weight of a Makita style power tool. Whereas the light flexible shaft allows you to feel more precisely how much pressure you are actually applying with the abrasive against the piece.

[Bernie Kopfer]

I have been using the Bosch 12V angle drill. since the chuck head angle is quickly adjustable it becomes easy to use both inside and on the outside of bowls. And the speed is definitely not fast.