Sanding speed

I usually sand at higher speeds, and the finer the grit the faster the speed. At some point I use the reverse switch on the lathe and continue sanding.

IMHO, heat is NOT your friend, so I try to sand a low speed and light pressure.. For bowl sanding I'd suggest a drill and a couple of these:

I use a $25 right angle drill... a Milwaukee knockoff.. works well for me..

Or, try this if you don't have or want to use a drill..

Very easy to make your own, also...

mac

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I mostly make bowls. I have tried a lot of sanding tools and techniques. I have also been told by others of many and varied ways to sand. One guy told me to always keep the lathe up on the fastest speed and use a drill. Another told me to always sand with the lathe off. The answer is somewhere in between.

I use several different sanding tools, depending on what the problem is and what part of the bowl is being sanded:

1. I use an inertia sander (Sorby Sandmaster) similar to the one Mac describes with the lathe at a fairly high speed. About 1000 to 1200 rpm. This works nice for smoothing out tool marks and with course grit sandpaper can get rid of some (not all) of the tear out you might get on the inside of the bowl. It also works very nice with finer grit paper because it does not leave many swirl lines or scratches.

1. I also use a cheap knock off 45 degree angle drill for bottoms of the bowl, the rim, and some of the tough spots. Usually this works best with the lathe on a slower speed. Anywhere from 100 to 600 rpm although I have been know to pump it up a little faster. It can also be used with the lathe stopped, although this can tend to dig in to the wood and cause dents and dimples especially with courser grits.

2. I recently purchased a random orbital air sander specially made for bowls from Packard. It is manufactured by Grex. You need to have a large air compressor to run this tool. I am still learning how best to use it. So far I have found that the best use of this tool is when the lathe is off and I am sanding the tough spots like end grain tear out, etc. It does not dig into the wood and make dimples, holes, nor scratch marks like the angle drill. It is harder to control when the lathe is running therefore so far I still use one of the other methods when the lathe is on.

1. Sometimes it is best to resort to good old hand sanding. Lathe can be on or off. Slower speeds are best for bowls and your fingers.

I have found that sanding at too high of a speed will usually cause other problems. Wears out sandpaper faster, causes checking of the wood, sends more dust flying, etc.

Hope this helps, Ted

Hi MGIB, Musing right along about the "best speed to use for sanding",

Ending up with hand sanding (which is slow speed) of a well tooled piece moving thru increasing grits using fresh good quality paper with the grain is probably the gold standard as there are so many variables with power sanding ...but it is too effective and convenient not to use. Here are a few variables that I think might impact "sanding speed". Just my take, not trying to be a condescending knowitall.

The timber's characteristics, the orientation of the timber's grain to the lathe and sander axes, the diameter of the piece, whether the abrasive rotates circularly or randomly or in a a linear direction with or across the grain. The abrasive itself and its backing and adhesives, The grit of the abrasive, the lubricants on the wood, the pressure of the abrasive against the piece. Whether the abrasive is driven by a power tool or by the piece itself or is hand held.

If the piece is spinning on a lathe, surface speed depends on the diameter of the piece as well as rpm of the piece and the abrasive. I'm assuming that you meant surface speed not spindle speed.

Whether the rotating sandpaper is in a random or circular orbit can be important.

Each rotation of a cross grain piece like most bowls, will present two areas that are a problem both for tooling and sanding due to tear out and scratches. They will be 180 deg apart. Probably best to sand the _problem area with the grain. Maybe by hand.

The same grits in different brands of abrasives don't cut the same. Anybody try those bargain H.F. sheets of aluminum oxide? If so, you know what Brown _can't do for you. Sandpaper is a cutting tool, not a burnisher and as with any edge tool it gets dull. We can clean its edges a little, but we can't sharpen them so it's best to replace worn abrasives. Life is too short for cheap sandpaper. I prefer Norton's 3X.

There is a difference between sanding a lubricated surface or between coats of a finish and sanding raw wood. Wiping off sanding dust between grits becomes important as the grits become finer.

When wood fibers have been burnished (pressed down) by excessive radial pressure of a dull turning tool or its bevel or by reusing dull sand paper, opposing rotations of abrasive and wood instead of climb (with the rotation) sanding is useful.

The speed at the periphery of a sanding disc is higher than near the center. BTW. are there variables that affect the 'to & fro' "speed" of a palm sander or the rpm of a belt sander relative to the wood?

I think you have to decide the "best speed" for each sanding situation. There are many strong opinions posted on rcw based on personal anecdotes or reading about someone else's anecdotes and so on. Often half truths and rigid rules are perpetuated. It's whatever works for you.

There's no always or never for sanding speed or for most anything else in woodturning and posting a personal opinion in capital letters doesn't make it so. RIGHT!! :)

Turn to Safety, Arch Fortiter

Some very interesting point, especially about hand sanding..

I find that the more I turn, the more I'm finding myself hand sanding.. especially on the finer grits..

Some weird shaped pieces are just easier to sand with the lathe stopped, IMO..

I power sand whenever I can, but a lot of my stuff is wet sanded with Danish Oil and you don't want to power sand them.. DAMHIKT

A real advantage of wet sanding is that the air stays a lot cleaner... I don't even use the DC when wet sanding..

I've tried using a flex shaft instead of the drill but I need a better flex shaft... Seems to be the way to go though..

mac

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More useful, wipe the surface with a wet rag to break the hardening and saturate the fibers. All the easier to cut them away after they stand up.

Speed means nothing in sanding. Pressure does. Pressure is friction, and that's grit breaking, dislodging, and paper heating the surface. Don't press!