Snail Scott on tue 10 oct 00
At 05:23 PM 10/10/00 -0600, you wrote:
>Hi, Linda.
>
>Use an angle grinder with a masonry disk. Be sure to use heavy gloves--and
>of course safety glasses, breathing protection--but the gloves aren't as
>obvious. Don't forget 'em or you'll eventually regret it. This tool will
>come in handy for all sorts of things like grinding glaze off shelves, and
>is well worth the $50-60 price. I have a Black & Decker, but I'm sure any
>reputable brand would be fine.
I love my angle grinder; it's a seriously cheap ($25)
Chinese-made thing, but clay dust can kill the motor
of a good one just as fast, and I can afford to
replace this one! Note, sometimes a serious grinder
like an angle grinder or bench grinder can chip the
'good' parts of the glaze, especially if it's thick,
so take it easy and don't let one spot get too hot.
(I don't use a lot of glaze, so my grinder gets more
use when fitting together the parts of a multi-part
sculpture. For the few glaze drips I get, I tend to
use the drill-with-grinder-bit, for more control.)
-Snail
vince pitelka on tue 10 oct 00
> Hi, thanks to everyone who responded to my last question regarding bisque
firing-
> you all were very helpful. Now I have another question: Does anyone have
a
> suggestion on how to grind glaze off of the bottom of a pot? I've been
grinding
> with a dremel (Aluminum oxide grinding stone bit) which is pretty slow
work. Is
> there a faster way to get this done? I love the pot and would hate to
throw it out.
Linda -
For grinding glaze off the bottom of pots, the ideal tool is a bench
grinder. You can get a decent bench grinder for about $50 at your
neighborhood home improvement center. Or, check grizzlyindustrial.com for
very good tools imported from Asia, including good bench grinders. A bench
grinder will make short work of glaze drips. However, as I have said before
on Clayart, you should only grind off a glaze drip if you are going to keep
the pot for yourself, or if you are going to sell it as a second. The only
exception to this is on pots which have been ground and then properly
polished, as in the macrocrystalline-glaze process, but that normally
requires very expensive grinding and polishing equipment. If some glaze
runs are an inherent part of your firing process, then you should get an
abrasive flap wheel (Graingers Supply has them) and mount that on one end of
your bench grinder arbor. It does a decent job of polishing occasional
glaze runs, and gives the bottoms of your pots a wonderful silky smooth
surface.
A bench grinder is a very handy tool for all sorts of grinding, shaping, and
sharpening tasks. You can sharpen your trimming tools and other metal
tools, and you can shape and sharpen wooden ribs and modeling tools on the
flat sides of the grinding wheels.
Good luck -
- Vince
Vince Pitelka
Home - vpitelka@dekalb.net
615/597-5376
Work - wpitelka@tntech.edu
615/597-6801 ext. 111, fax 615/597-6803
Appalachian Center for Crafts
Tennessee Technological University
1560 Craft Center Drive, Smithville TN 37166
http://www.craftcenter.tntech.edu/
Linda & Malcolm on tue 10 oct 00
Hi, thanks to everyone who responded to my last question regarding =
bisque firing--you all were very helpful. Now I have another question: =
Does anyone have a suggestion on how to grind glaze off of the bottom of =
a pot? I've been grinding with a dremel (Aluminum oxide grinding stone =
bit) which is pretty slow work. Is there a faster way to get this done? =
I love the pot and would hate to throw it out. Thanks in advance. =
Linda.
Snail Scott on tue 10 oct 00
At 12:41 PM 10/10/00 -0400, you wrote:
>Hi, thanks to everyone who responded to my last question regarding bisque
firing--you all were very helpful. Now I have another question: Does
anyone have a suggestion on how to grind glaze off of the bottom of a pot?
I've been grinding with a dremel (Aluminum oxide grinding stone bit) which
is pretty slow work. Is there a faster way to get this done? I love the
pot and would hate to throw it out. Thanks in advance. Linda.
I like to use a grinding (stone) bit in my drill. The
larger diameter and higher RPM help speed things up.
Bits of this type (about 1" diameter, with about a
1/4" diameter shank) aren't too expensive...look near
the dremel bits in a hardware store. A bench grinder
is faster, but only if you've got one.
Cindy Strnad on tue 10 oct 00
Hi, Linda.
Use an angle grinder with a masonry disk. Be sure to use heavy gloves--and
of course safety glasses, breathing protection--but the gloves aren't as
obvious. Don't forget 'em or you'll eventually regret it. This tool will
come in handy for all sorts of things like grinding glaze off shelves, and
is well worth the $50-60 price. I have a Black & Decker, but I'm sure any
reputable brand would be fine.
Cindy Strnad
Earthen Vessels Pottery
RR 1, Box 51
Custer, SD 57730
USA
earthenv@gwtc.net
http://www.earthenvesselssd.com
Martin Howard on wed 11 oct 00
A power file does the job for me. The flat part does the bottoms nicely and
the point is useful for the odd bubble elsewhere.
Martin Howard
Webb's Cottage Pottery
Woolpits Road, Great Saling
BRAINTREE, Essex CM7 5DZ
England
martin@webbscottage.co.uk
Fabienne Micheline Cassman on wed 11 oct 00
Vince,
I was wondering if you could go one step further with the grinding tools
information. I finally received the Grizzly catalog. I was wondering what
grit and material the flap wheel should be made of. What about the silicon
carbide bench grinding wheel, what grit, 60, 80, 120? The goal is to have
the bottom of the pots as smooth as a baby's bottom :)
Thank you,
Faye swimming in crystals :)) and positively grinding challenged
--
Milky Way Ceramics http://www.milkywayceramics.com/
Yes, I have learned from my mistakes...
I can reproduce them exactly.
vince pitelka on fri 13 oct 00
> I was wondering if you could go one step further with the grinding tools
> information. I finally received the Grizzly catalog. I was wondering
what
> grit and material the flap wheel should be made of. What about the
silicon
> carbide bench grinding wheel, what grit, 60, 80, 120? The goal is to have
> the bottom of the pots as smooth as a baby's bottom :)
Faye -
Abrasive flap wheels are always made of tightly bound strips of heavy emery
cloth. I believe the ones I have been using are 100-grit, and yes, they
will give a beautiful satin-smooth finish, especially after the flap wheel
is broken in a bit. Industrial abrasive suppliers have them - you can
easily find them on the Internet if you search the Thomas Register for
abrasive supplies. I buy mine from Grainger's Supply, which you can access
via their website. I do not have my Grainger's catalog here, but the
abrasive flap wheels are listed among the other grinding-wheel supplies.
They call them something else, so you have to do a little digging to find
them. If you cannot find them, I can look in my Grainger's catalog next
week. I believe that the abrasive flap wheels have a 1" bore, and when you
order them, you also need to order a set of bushings to fit your grinder
shaft. They will be listed along with the abrasive flap wheels.
Normally a bench grinder will come with a fine and a coarse wheel - perhaps
80 grit and 120 grit. I'd take off the coarse wheel and replace it with the
abrasive flap wheel. Grit ratings on abrasives are a bit misleading. A 120
grit grinding wheel be great for sharpening trimming tools and other tools,
and will hog off the occasional glaze run very effectively, but will leave
an obviously ground surface which is not very smooth. The 100-grit abrasive
flap wheel, even though it is a coarser abrasive rating, will give a much
smoother finish because it is a flexible grinding medium.
>From your post it sounds like perhaps you are doing macrocrystalline glaze.
If this is a serious endeavor for you, then you already realize that the
above is an entirely inadequate solution for grinding the glaze runs on
macrocrystaline-glazed pots. You need the kind of glass-grinder that
glassblowers use. Plan on spending a few grand. That will give you a
finish as smooth as glass.
For other applications, the abrasive flap wheel will do a wonderful job of
giving a satin smooth finish on all pot bottoms. As I mentioned in an
earlier post, in salt/soda or wood firing some glaze runs are inevitable,
and the grinding-wheel and abrasive flap wheel will make a great combination
for dealing with those runs. For other potters, the objective should be to
avoid glaze runs. And as I said, when they do occur, the pot is a second,
unless you can really grind away all traces and polish it very smooth with
the abrasive flap wheel. That's not really worth the time.
Best wishes -
- Vince
Vince Pitelka
Home - vpitelka@dekalb.net
615/597-5376
Work - wpitelka@tntech.edu
615/597-6801 ext. 111, fax 615/597-6803
Appalachian Center for Crafts
Tennessee Technological University
1560 Craft Center Drive, Smithville TN 37166
http://www.craftcenter.tntech.edu/
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