[Clayart] SANDY BOTTOMS

[Robert Harris]

Personally, I'm really against using bench grinders because of the amount
of silica dust they put out. and the 2.5 micron stuff that really harms
your lungs stays in the air for 24 hours before settling (so wearing a mask
while you're doing it doesn't really cover you). Unfortunately, the dust
that makes you cough (10+ microns) isn't the bad stuff.
Now admittedly, very very few studio potters get silicosis (and in the ones
that do it's almost always co-caused by smoking), but why add to the risk?

These days there are plenty of diamond grit solutions (like Hank mentioned)
that fit on a wheel that allow water grinding.
I've also seen solutions where people use air powered angle grinders
combined with water (which is essentially how they cut granite countertops)
if you really have a need for speed. If you look at the granite countertop
industry in general, they solved these problems years ago (most of the
diamond pads etc are sold to them).

 All in all, wet sanding is much, much safer.

On Sun, May 1, 2022, 13:55 <vpitelka at dtccom.net> wrote:

> I wrote about this in one of my Clay Times columns.  I am always looking
> for
> efficient ways of doing things without sacrificing quality and
> craftsmanship.  I soda fire to cone-8 and sand the bottoms or feet of every
> piece.  I've always done that, and when I was a production studio potter in
> Northern California that was a hell of a lot of pots. I discovered abrasive
> flap wheels around 1975 and since them have always used them to sand the
> bottoms.
>
> Search Amazon for "Norton Metalite R265 Abrasive Flap Wheel, 1" Arbor,
> Round
> Hole, Aluminum Oxide, 6" Dia., 1" Face Width, Grit 120, 6200 Max RPM" but
> be
> sure to also get "Norton Aluminum Reducing Bushing for 4 - 6 Abrasive Flap
> and Convolute Wheel, Reduces Hole Size to 1/2, 1 Arbor Model: 66261080523."
> Those are the bushings you need to adapt to the 1/2" arbor on your bench
> grinder.  You'll only have to buy the bushings once, because they fit all
> flap wheels with a 1" center hole.
>
> If you happen to have a spare 1/4 to 1/2 HP electric motor around, you can
> get a "motor shaft arbor extension" to fit the 1/2" or 5/8" motor shaft.
> It
> features a 1/2" arbor to mount the abrasive flap wheel.  That's what I did
> when I had Railroad Stoneware.  I mounted the motor on a stand, and sanded
> the bottoms of every pot as I unloaded the car kiln.
>
> If you don't have a an appropriate electric motor lying around, you are
> best
> off buying a bench grinder, because they are no more expensive than a new
> electric motor.  They are very reasonably priced, and you can use them to
> sharpen your trimming tools and shape your modeling tools.  The Skil 6"
> bench grinder I got for my studio does not seem to be available, but the
> "G9717 6" Bench Grinder with 1/2" Arbor" from grizzly.com for $57 is a
> good
> deal.  Grizzly Industrial does a good job of maintaining high quality on
> the
> products they sell.  Mount the grinder on a table or workbench in your
> studio or buy a stand for it.  I have a bench grinder in my workshop and a
> second one in my studio that has a grinding wheel on one end for grinding
> off glaze runs and soda deposits, and a abrasive flap wheel on the other
> end
> for sanding the bottoms.  It makes quick work of the sanding.
>
> I bought two of the "WEN 4288T Cast Iron Bench Grinder Pedestal Stand" from
> Amazon for $56 apiece for my bench grinders, and they worked out great.
> They are a bargain.
>
> If you buy a bench grinder for this application, remove the grinding wheel
> from one end and save it as a spare, and then remove the guard and the tool
> rest from that end as well in order to give maximum access to the flap
> wheel
> when sanding your work.  NEVER REMOVE THE GUARD ON A GRINDING WHEEL, but
> with a flap wheel, the guard is just in the way.  The grit and bits of
> fabric thrown off by a flap wheel will do you no harm as long as you ALWAYS
> WEAR PROPER EYE PROTECTION whenever using any sort of grinder or sander.
>
> Here's a bit of common sense shop safety protocol for bench grinders.  This
> is not so important in your own studio or workshop, but a very good habit
> to
> develop for the occasions when you use a bench grinder somewhere else.  If
> someone was walking through the workshop or studio with a length of angle
> iron or a long two-by-four and accidently whacked one end against the
> grinding wheel on a bench grinder and cracked it, the wheel would likely
> explode from centrifugal force upon startup.  So, as standard protocol,
> always stand off to the side when you start a bench grinder with a grinding
> wheel.  That way you're out of the line of fire.  Staying out of the line
> of
> fire is very important whenever people are using power tools or machine
> tools and equipment.
> - Vince
>
> Vince Pitelka
> Potter, Writer, Teacher
> Chapel Hill, NC
> vpitelka at dtccom.net
> www.vincepitelka.com
> https://chathamartistsguild.org/
>
> -----Original Message-----
> From: Clayart <clayart-bounces at lists.clayartworld.com> On Behalf Of Mike
> Gordon
> Sent: Saturday, April 30, 2022 6:22 PM
> To: Clayart international pottery discussion forum
> <clayart at lists.clayartworld.com>
> Subject: [Clayart] SANDY BOTTOMS
>
> Does anybody else have this problem??? All the feet on my bowls, cups have
> to be sanded smooth. Otherwise they feel like sand paper! Mike Gordon Cone
> 6
> in a gas kiln.=
>
>
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