The Wrights on mon 11 aug 97
Here I am again as promised in my "wheel shaking" e-mail. Now I have a
technique question. I have had a terrible time with trimming. I think
it is one of the things that keeps me from persuing pottery as a primary
source of income. I have tried and tried and tried. I probably would
have a huge pile of thrown ware, except for having to trash pieces
because I footed them off center, trimmed through the bottom, warped the
top rim trying to press clay around the piece to keep it from moving
while I'm trimming the bottom sides....to put it simply AAAAAAAH!!!!!
I center, throw and cut off the wheel relatively successfully
considering I can't do practice pottery full-time. When I was in school
I followed my glaze recipes very well and almost always was pleased with
my results, even if they didn't turn out exactly as expected. I hand
wedge my clay and very rarely have air pockets. But as I inferred
above, it's all downhill when it comes to trimming and footing. I have
looked for help in books and magazines and still find little explanation
of how to center for trimming, trimming and footing. I can explain that
to anyone who needs to know but, I have so much trouble doing it. I'll
explain my procedures along with what potentially happens and maybe
someone might see a flaw in what I'm doing.
I will explain as though I were working on a simple cup or vase form.
I cut the leather hard pot from the wheel, so far so good.
I turn it upside down visually centering it on my wheel head or a bat.
Using my needle tool, I gently inscribe a circle on the bottom of the
pot. I check the distance all the way around and slightly adjust the
pot. Repeating this inscribing and adjusting process, I continue until
I have it centered. Textbook instructions right? A great portion of
the time, I do this so much that the entire bottom of the pot is used up
and I can't tell which line is which. I sponge or rub out the lines and
start over again. If I'm lucky, I FINALLY get the thing centered. I
take small balls of clay and press them around the pot onto the bat in
order to hold the pot in place.
Sometimes even when I am being careful, the pot slips out of place and I
have to start the whole blasted process over again. Also, sometimes
when I trim, the pot is still not holding steady, and I press the clay
balls down more, I warp the lip of the pot.
Next challenge: Using a very thin wire trim tool I gently trim around
the base of the pot and the bottom, adjusting the shape and using a rib
tool to smooth out the trim lines. I have trimmed too thin and trimmed
through so many pot bottoms, I couldn't even count the times. I found a
wonderful idea in one of the little CM books, (can't remember which one)
of using thumb tacks inside the pot and trimming until the points show
through. I tried that and had some success. I figured it will help me
at least until I can get the other problems narrowed down.
I know pottery requires patience and lots of it. I know there isn't a
100% success rate. I know it is a huge challenge. Fortunately, I love
it enough to want to jump these obstacles. I feel so stupid and
uncoordinated that I can't do these basic techniques. Even when I was
in the studio as a student 30-40 hours per week (would have been more
except for having to work), I didn't seem to improve on these
techniques.
I'm sure there is some patient kind hearted potter who would have mercy
on this frustrated "amateur", and give me some advice. Unfortunately,
we are financially tight so I can't afford to take classes, and I can't
afford to "volunteer" as an apprentice in a studio. Unless, I could get
a paid part-time apprenticeship in my area. So, I have to get help this
way.
Thanks alot in advance for your help.
Take care everyone, e you soon.
Flo
Boyd on tue 12 aug 97
Stick a tack through the clay from the inside, when you hit the tack you will
know the thickness.
Good luck
Boyd
Iron River MI
http://www.freeyellow.com/members/boyd/index.html
PATSYCATS on tue 12 aug 97
A couple of thoughts for you:
Timing is important. If the pot is too soft or too hard, trimming is
nightmarish. Pots should be firm leather hard in my opinion.
If the pot is thrown centered in the first place, it may simply be
necessary to visually center the upside down pot for trimming. I do it
directly on the wheel head so that I can see those concentric circle that
are inscribed on the metal head.
Make sure that you are spinning the wheel fast enough during trimming.
This will distribute the action of the trimming tool all the way around
the pot evenly.
I use a thicker "ribbon tool" rather than a really thin wire tool.
Practice tapping on the pot as a way of judging thickness. Thick areas
have a lower, duller sound. Thin areas sound more hollow.
Consider focussing on forms that don't require foot rings. Maybe you can
shape the bottom of the pot at the end of throwing to look a little bit
like a foot ring. Or maybe you could add a coiled foot. I make a lot of
pots with out a foot ring of any kind.
Good luck to you, Patsy
Cindy on tue 12 aug 97
Flo,
Trimming is one of the big challenges of potting and can certainly be
frustrating. Here are a few tips:
1.) Don't trim immediately after removing your pot from the bat. It sounds
as if your rims are too flexible and most likely your bases are still too
soft. If the rims begin to get too dry, you can always set them in a
plastic grocery bag while the bases firm up. Wait until the base does not
easily accept the impression of your fingers--no longer, though. Wait until
you can no longer adjust the rims with your hands--but not so long that
they begin to lighten in color. Much trouble can be avoided by exercising a
bit of patience.
2.) Don't trim at all after removing your pots from the bat if you can help
it. I seldom trim mug bottoms, for instance. I leave the mugs stuck to my
masonite bat for a day or two (my basement is mondo damp) until they've
reached the stage described above. I replace the bat on the wheel and trim
the base into a nice shape before removing the mug. Hint: you want some
undercutting usually in order to give the pot some lift and to make removal
easier. When I have the contours right, I cut the mug from the bat (while
rotating of course) with a clean (rub it on the cement floor) fettling
knife. Smooth the bottom with a rubber rib, your fingers, whatever works
for you.
Vases and urns I make with very small bases (that's just the way I like
them). The small base serves instead of a foot to give the pot a certain
amount of lift from the table or whatever. I trim them the same way I do
the mugs.
Sometimes I make wide-bottomed pots. In that case, I either have a rounded
footring which is slightly wider than the walls or I undercut slightly with
a wooden wedge-ended tool. With wide-bottomed pots, I use the lack of lift
as a feature. They seem solid--well-rooted. Very nice for pitchers and
other things you don't want to be easily knocked over. I always smooth the
bottoms. Sometimes you can't smooth right away, though, especially with a
wide bottom. The pot needs a little longer to dry first so you don't push
the bottom in.
3.) Of course some pots really need to be footed. I like to trim footrings
on cereal/mixing/etc. bowls, for instance. Sometimes, too, it's just easier
to smooth bottoms by turning upside down even if you don't want a footring.
If I'm only trimming one or two bowls, I invert them on the slightly damp
steel wheelhead. The rims can't be too dry, BTW, nor too wet. Here are two
ways of centering:
a.) Rotate the wheel slowly while holding a needle tool gently against the
outside, vertical wall of the pot. Rotate only once. If the pot is on
center, there should be an impression all the way around. Probably, your
tool will fail to touch the pot's walls in some places. Move the pot
towards the unmarked sides and try again, but raise or lower your tool
slightly. Do this until the pot is fairly well centered. Doesn't have to be
perfect.
b.) Use the same method, but instead of a needle tool, use your finger.
When you feel your finger touching the outside wall, stop the wheel and
adjust the pot in the manner described above. This won't work with a
kickwheel, because you have to be able to stop the wheel quickly. Start
with the first method and move on to the second method later if you feel
comfortable doing so.
Okay, so here's the bowl on the steel wheel. What holds it down? Just hold
it in place gently/firmly and rotate the wheelhead a fraction. Unless the
bowl has an inward-curving rim, it should be stuck firmly enough for
trimming. Vacuum and the interaction of clay/water/steel does this. I don't
really understand it, but it works. When you're ready to remove the pot,
just hold it steady while you give a bit of power to the wheel. The pot
should come right off, and it almost always does, too. Touch up the rim
with your finger to remove clinging wet clay or whatever. Warning: This
*WILL NOT* work if your rims are too wet or too dry.
If you're trimming a lot of bowls or a lot of other similar forms, throw a
chuck. Simple--just center a correctly-sized mound of clay, clean off the
wet surface with your rubber rib, and invert the bowl over the mound of
clay. The clay will hold the form steady while you trim. You can do this
for bottles, lids, and other difficult forms, too, by hollowing out the
chuck and raising thick walls to sufficient height, and placing the pot
inside the chuck. That gets awkward, though. I trim lids on the pots they
belong to, and treat the other stuff the way I treat mugs and vases. (After
all, the more time I have to spend, the more I have to charge. I like to
give people a quality product at the lowest price possible, and one way to
do that is to keep trimming/footing for forms that really need it.)
4.) The actual trimming goes something like this. Is the pot heavy? I stick
a needle tool through the side close to the bottom to see if it's too
thick. Then I have some idea how much trimming to do there. Some
wide-bellied forms are hard to throw as thin as I like at the
bottom--they'll collapse. Bowls can be like that too, especially if you
haven't thrown a lot of bowls. I trim that extra thickness off first, using
the big, pear-shaped tool and/or a flexible metal rib, then I trim the
outside of the footring using the shortest edge of the triangle-shaped loop
tool. I like the footring to angle out from the pot, because it looks nice
and because that means I can hold on to it easily for glazing. (Sometimes I
like to dip just the rim in a contrasting color. That can be a problem if
you can't get a good grip on the bowl.)
For trimming the inside of the footring, I start with a rounded loop tool,
as it seems better able to get a start cutting the flat bottom of the pot
without using an excess of pressure. I was taught to start with the outside
of the ring, but I generally start at the center and work out. You gotta do
what works best for you. Once I have the inner hollow roughed out, I go to
the flat side of the loop tool and smooth things up until I like the looks
of it.
As for trimming through, we've all done it. I can only tell you to check
the thickness of the bottom with your needle tool before trimming (those
little punctures heal over--no problem) and to tap periodically on the
bottom with your finger or with a tool. After a while, you'll learn the
sound and feel of a bottom that's getting too thin. Eventually, you'll
throw all your pots with consistent thickness in the bases so you won't
have to make as much fuss over this step. Your hands will know what to do
intuitively.
I hope this helps, Flo. I know how frustrating that trimming can be until
you get the hang of it, so hang in there.
Cindy
Karen Gringhuis on tue 12 aug 97
Flo - You MUST learn to tap on center - to center a revolving pot w/
a gentle tap of your hand. I can't explain it in words - everyne does
it differently. Me - when the high side gets to 12 o'clock, I tap w/ my right h
anything. It's worth the time to get it learned.
Footing off-center is no big deal. You center the foot, not the rest
of the pot. I purposely distort my rims so they are not the exact
same circle as feet. Just try to make the feet themselves round
before you cut them off. Sometimes they're just not round so
trim anyway & don't worry about it.
Make sure your balls of clay to anchor the pot are soft & push
them straight down - they will move themselves tight to the pot
wall.
Do NOT (IMHO) spend money on a Giffin Grip. They work on the
assumption that your rim circle has the same axis as your foot.
A very erroneous assupmtion IMHO. I use mine only to trim
plates.
New suggestion - take a sail rib & cut off the point to be
a hgt. that you want your average foot to be. Angle
the top edge of it back sharply. After you get your wall started
up, push s
the cut off end against the side wall where the foot will be.
This will pre-determine the approximate hgt. of your foot. Then
continuew shaping above this. If well done, the foot edge then
requires little or no real trimming.
Also depending on the shape of your pot, you can trim it while wet
& right=side up - believe it or not. The wooden pointed 1"
wide or so Kemper tool will do this. If you throw on bats,
leave the pot on the bat NOT cut off to set up a little, then
replace bat & pot on wheel & again trim right side up before
cutting off bat.
Above all, work on your throwing, The goal is to throw the
shape, NOT trim the shape. Trim as much as you need to but
keep throwing better next time.
If you post your geographic locality, perhaps someone here
is a neighbor who would help you.
Good luck. Karen Gringhuis
Paul Kaplan & Marilyn Price on tue 12 aug 97
The Wrights wrote:
> ----------------------------Original message--------------------------
> Here I am again as promised in my "wheel shaking" e-mail.
Try using a Giffin Grip. Makes life easy when centering.
Gina Dewar on tue 12 aug 97
Flo,
I find the Giffin Grip a wonderful time saver, and it holds everything
perfectly centered for me while I trim. If you can possibly add this to your
pottery tools it is worth every penny! As for trimming the right thickness,
try tapping your work, then trim a little, tap again, etc. You will soon
learn to recognize the sound of clay that is just the thickness you like. I'm
still a beginner at all this, but I find the Giffin Grip and tapping sure do
work for me.
Unruly JuliE on tue 12 aug 97
Flo -
One way of telling how thick you clay is when trimming is to tap on the
various parts of the "bowl" (for instance). Learn the sounds of the
thick leatherhard clay. As you trim, stop and tap again. The sound
begins to change. Eventually you will get the hang of that and will not
lose so many pots.
Trimming tools are "ribbon tools" not wire tools. Ribbon tools are
about 1/8" wide (not thick) and have sharp edges on both sides (sorta'
like a double sided knife, but not that SHARP!!!). A wire tool is for
sculpting clay. The sharp edge will make a big difference on trimming.
Dull trim tools are not worth a darn!
And if you can possibly afford one, buy a GIFFIN GRIP. This is a
self-centering contraption that fits on you wheelhead sorta' like a
bat. You can take a piece off and put it back on, recentered almost
instantly. I would never be without one again (of course I am spoiled
with it!)!!! You can find them for as low as $125.00. Save your
pennies and you will be glad you did!
Hope this helps.
JuliE in Michigan where it certainly feels like fall!! 540 for a high
today! BBUUUURRRRRRRR!!!!!!!
cobbeldi on tue 12 aug 97
Flo, trimming takes lots of practice, but I think you are unneccesarily
complicating the process. I do most of trimming when I throw using wooden
ribs. Pot thickness judging comes with time. Using a needle to measure
the bottom thickness is my best way to judge bottom thickness and to know
how much to trim off. When I cut the leather hard pot off of the bat, I
turn it upside down, hold my finger steady up against the pot, and keep
adjusting the pot until the pot is hitting my finger evenly all the way
around. The clay chucks I use are secured to the bat, not the pot,
therefore, I don't warp the rim. The bottom and the sides of the pot are
smoothed with a rib, and any trimming is done with a large and a small
looped trimming tool. You can also judge the thickness of the walls by
learning to judge the sound it makes when you thump the side and bottom of
the pot with your finger. Go slow, and keep checking, even if it means
taking the pot off of the wheel, checking it and then re-centering it and
trimming some more. See if there are any potters in your area who will
allow you to come to their studios and observe their trimming techniques.
Every potter that I know is more than happy to give pointers to a beginner
and allow them to observe.
Hope I was of some help.
Debra in Alabama
----------
> ----------------------------Original message----------------------------
> Here I am again as promised in my "wheel shaking" e-mail. Now I have a
> technique question. I have had a terrible time with trimming. I think
> it is one of the things that keeps me from persuing pottery as a primary
> source of income. I have tried and tried and tried. I probably would
> have a huge pile of thrown ware, except for having to trash pieces
> because I footed them off center, trimmed through the bottom, warped the
> top rim trying to press clay around the piece to keep it from moving
> while I'm trimming the bottom sides....to put it simply AAAAAAAH!!!!!
>
> I center, throw and cut off the wheel relatively successfully
> considering I can't do practice pottery full-time. When I was in school
> I followed my glaze recipes very well and almost always was pleased with
> my results, even if they didn't turn out exactly as expected. I hand
> wedge my clay and very rarely have air pockets. But as I inferred
> above, it's all downhill when it comes to trimming and footing. I have
> looked for help in books and magazines and still find little explanation
> of how to center for trimming, trimming and footing. I can explain that
> to anyone who needs to know but, I have so much trouble doing it. I'll
> explain my procedures along with what potentially happens and maybe
> someone might see a flaw in what I'm doing.
>
> I will explain as though I were working on a simple cup or vase form.
> I cut the leather hard pot from the wheel, so far so good.
> I turn it upside down visually centering it on my wheel head or a bat.
> Using my needle tool, I gently inscribe a circle on the bottom of the
> pot. I check the distance all the way around and slightly adjust the
> pot. Repeating this inscribing and adjusting process, I continue until
> I have it centered. Textbook instructions right? A great portion of
> the time, I do this so much that the entire bottom of the pot is used up
> and I can't tell which line is which. I sponge or rub out the lines and
> start over again. If I'm lucky, I FINALLY get the thing centered. I
> take small balls of clay and press them around the pot onto the bat in
> order to hold the pot in place.
> Sometimes even when I am being careful, the pot slips out of place and I
> have to start the whole blasted process over again. Also, sometimes
> when I trim, the pot is still not holding steady, and I press the clay
> balls down more, I warp the lip of the pot.
>
> Next challenge: Using a very thin wire trim tool I gently trim around
> the base of the pot and the bottom, adjusting the shape and using a rib
> tool to smooth out the trim lines. I have trimmed too thin and trimmed
> through so many pot bottoms, I couldn't even count the times. I found a
> wonderful idea in one of the little CM books, (can't remember which one)
> of using thumb tacks inside the pot and trimming until the points show
> through. I tried that and had some success. I figured it will help me
> at least until I can get the other problems narrowed down.
>
> I know pottery requires patience and lots of it. I know there isn't a
> 100% success rate. I know it is a huge challenge. Fortunately, I love
> it enough to want to jump these obstacles. I feel so stupid and
> uncoordinated that I can't do these basic techniques. Even when I was
> in the studio as a student 30-40 hours per week (would have been more
> except for having to work), I didn't seem to improve on these
> techniques.
>
> I'm sure there is some patient kind hearted potter who would have mercy
> on this frustrated "amateur", and give me some advice. Unfortunately,
> we are financially tight so I can't afford to take classes, and I can't
> afford to "volunteer" as an apprentice in a studio. Unless, I could get
> a paid part-time apprenticeship in my area. So, I have to get help this
> way.
>
> Thanks alot in advance for your help.
> Take care everyone, e you soon.
> Flo
>
Robert Speirs, M.D. 12 4450 on tue 12 aug 97
Dear Flo,
I can just feel your frustration and empathize with you very much. I am
sure you're going to receive tons of advice on this. Here is mine:
First, be sure you trim your bottom very evenly with your wooden tool at
the end of throwing your form before cutting it off your bat. Your pots
need to be at the proper wetness/dryness before trimming, too. Since I
have never been able to master tapping onto center, I hold my fingertip
against the bottom rim while the wheel is turning, and, when the pot
ceases to touch my finger, I pull it that direction. (you have to do
this repeatedly) When I think my finger is touching it all the way
around, I then use my needle tool on the bottom to "check" myself like
you've been doing. If the line doesn't meet, it isn't centered! Then,
if it's not centered, I hold the needle tool where my finger was feeling
(side of the foot) and see if that will tip me off where the error is.
Wherever the needle tool makes a mark, push it away from you slightly.
With patience, I can get it centered perfectly.
Instead of using balls of clay to hold my piece, I learned, from
watching a video of Warren MacKenzie, to wet the rim with a sponge, put
it on the wheel and center. When it is centered I press down with my
whole palm to get a good seal. This way I won't distort the rim with
clay balls. It holds really well for me against the metal wheel. You
can't really use this method with tall pieces, but I often trim those
right side up without cutting them off the bat if I have a flat bottom
without a foot.
As for trimming through the bottoms, I can't help you much. I seem to
have a sixth sense about it and have hardly ever done it. I will tell
you that I am very conservative when trimming the bottoms and don't push
my tool very aggressively.
Well, I hope I explained this clearly. Best of luck with a frustrating
situation.
Laura in Oregon
Craig Martell on wed 13 aug 97
Hi Flo:
I think that Patsy gave you some real good advice, such as, you may not need
to trim everything.
Try throwing some of your forms as completely as possible and use ribs or
throwing sticks to finish and embellish them while in the upright position
and fairly soft. I have several wood "profiles" that I have made to accent
the feet of cylindrical and eliptical forms, so I don't have to do any or
much turning to finish them. I think Robin Hopper has a section in his book
"Functional Pottery" about using profiles. You can also use them on rims.
You can also turn some straighter, taller forms in the upright postion, a
few hours after they have been thrown. Don't cut them off until you've
turned away the clay that you don't want or wet the bottoms and restick them
to the bat or wheelhead.
You might also want to try using chucks and chums to hold some of your forms
while you turn away clay. Chucks are cylinders of clay that you make to
accept a pot that is hard or impossible to key down with wads. Bottle forms
are a good example. You center the chuck and key it to the bat or wheelhead
and invert the pot to be turned inside the chuck. The pots don't have to be
recentered usually but they do need to be leveled. For this I use a small,
round bubble level about the size of a 50 cent piece. Put the level on the
center of the pot bottom and adjust the tilt of the pot until the bubble is
in the bullseye and you are ready to turn. Chums are thrown mushroom shaped
forms, hollow in the center so you can tap the foot to assess thickness,
that you invert forms over to turn. I use chums to turn teabowls, rice
bowls, soupbowls, small bowls of 10 inches or less. When using a chum, you
don't apply pressure to the rims of pices with clay wads so there is no
distortion. You can also turn the entire outer surface of the piece if you
want. There are no wads in the way, and most of the centering is already
done. If the pots are starting to get dry, you will need to moisten the
contact area on the chuck or chum as well as the pot. Use one of your
fingers to apply pressure while turning to hold the piece securely. Also,
use a medium to med. fast wheel speed.
Teach yourself to tap pots to center. Place them as close to center as
possible and with the wheel turnig at about med speed, tap the pot perfectly
on center. The only technique I can reccomend here is to tap lighly and even
more lightly as you approach perfect center. You CAN learn to do this!!! I
did, so you can. You will not need to draw rings on the pots, you will be
able to tell, by eye, when they are centered.
Design your pots for turning, make the rims thicker if need be to accept
the clay wad method without distortion. If you are going to want a foot
ring, think about that while throwing the piece and be generous with the
clay. When throwing the piece, check the thickness of the bottom with a pin
tool so you know that there is enough clay to make a foot ring. Remember to
follow the original form when turning and don't attemp to radically alter
the profile of the piece by turning a lot away. We used to try to save bad
forms by turning when I was in school and we usually wound up with nothing,
or a worst pot than we imagined so I'm speaking from experience here.
Turning is a skill, like throwing, glazing, firing, and it takes some time
to learn. Remember to enjoy the process while you are struggling with it.
Regards, Craig Martell-Oregon Hope this helps!!
Bliss, Kris on wed 13 aug 97
>----------------------------Original message----------------------------
>Here I am again as promised in my "whusting process, I continue until
>I have it centered. Textbook instructions right? A great portion of
>the time, I do this so much that the entire bottom of the pot is used up
>and I can't tell which line is which. I sponge or rub out the lines and
>start over again. If I'm lucky, I FINALLY get the thing centered. I
>take small balls of clay and press them around the pot onto the bat in
>order to hold the pot in place.
>Sometimes even when I am being careful, the pot slips out of place and I
>have to start the whole blasted process over again. Also, sometimes
>when I trim, the pot is still not holding steady, and I press the clay
>balls down more, I warp the lip of the pot.
>
>
.. I have trimmed too thin and trimmed
>through so many pot bottoms, I couldn't even count the times. I found a
>
here's a trick for you on your pot bottoms, after you have
your pot upside down and centered, tap tap tap on the center
hear how it sounds solid ? well, as you are trimming towards
the ring, at each pass, tap tap tap, when it sounds hollow,
stop.
Try this, a coupla times, may be it will lower the number of
wasters.
Note: this won't work if your work is too dry.
BTW, i put a foot ring pretty much everything.
>
kbliss@customcpu.com
13781 Arne Erickson Cir.
Anchorage, Alaska 99515
A.K.Farrell on thu 14 aug 97
Flo,
I've definitely had my share of the sort of trimming problems you describe.
One of the things that struck me as I read your message is that although
I originally used the centering method you described, I don't think I've
done it that way for a couple of years. Partly that has to do with the kind
of pots I'm making, I think. There are a few approaches you might try;
they do all take practice.
For centering, you can "knock" the pot on center. With the wheel spinning
fairly slowly, watch the pot and identify the "bulge" where the pot
sticks out from the center. Let it go around a few times so you can
predict the next time that bulge goes past your hand and give it a gentle
tap when it does. (Have your other hand ready to stop the pot on the
opposite side in case you're not all that gentle!) Richey Bellinger
demonstrated this in a class I took. It took me quite awhile to get it, and
I'm not sure if I'm doing it "right" or describing it well, but somehow
I get my pieces centered and I don't have to inscribe the sides in the
process. Richey suggested practicing with a piece of bisque ware until
you get the feel of it.
The above seems to work best with pots that are about as tall as they are
wide; it's trickier with tall narrow pieces but can work. Occasionally I
center a narrow piece for trimming by simply holding my hands gently around it
(as if I were collaring in, sort of), until I can feel the piece is centered.
I've never witnessed anyone teach this, but it works for me.
To hold the piece in place, note that low wide pieces (bowls, platters, short
mugs) will hold themselves in place with a thin film of water under the rim.
This forms a seal which keeps the piece from moving. (Too much water and the
piece will slide around -- and you'll dissolve part of the rim!) You can wipe
the wheel head with a damp sponge, then tap/knock it on center and finish with
a light tap or press on the base of the pot (top) to seal it. Helpful hint:
when (not if) you get a piece stuck to the wheel before you center it, don't
try to pull it off! Wait for the seal to dry or add additional water to slide
the pot to the edge of the wheel. It's like a suction cup; get an edge off and
the suction is gone.
You can also center the piece, then squeeze a little water around the edge and
give it a moment to seep under the pot and form a seal.
For the actual trimming, I've settled on tapping the piece and listening
to the tone to determine whether it's thin enough. You will trim through
the bottoms and sides of a few pots on the way to learning to do this
correctly. I'd rather lose one now and then than leave an unnecessarily
thick and heavy base, but I have a collection of doorstops to attest that
it wasn't always so! The piece should make about the same sound when
you tap a side as when you tap the trimmed base.
Trim the center of the base first, so that you leave clay around the edge
to support what you're trimming.
Before you put the piece down to trim, you want to feel down the inside and
outside with both hands, taking note of where it thickens and what the curve of
the inside shape is. (I mention this late in the process because that's when
I think of it, I guess.)
I've been told it makes a difference whether your wheel is level. Picture a
cylinder: when you pull up, you're pulling straight up (against gravity),
so if the wheel is not level the base of your pot won't be perpendicular
to the sides.
Keep in mind too that many forms don't require a foot. Many mugs, vases with
narrow bases, etc. look just fine without one. Open the piece close enough
to the wheel head that you won't need to trim. After forming the shape, you
can use a wooden knife to trim the excess off the base (using just the point
and holding the knife VERY firmly while cutting down at an angle into the
turning pot). You can also trim such a piece "upside down?" once it is leather h
on the base of the piece will help compress the clay and guard against cracking.
Keep at it! Remember that you get more practice throwing than trimming (you
don't trim your throwing rejects), so it probably will take some time for
your trimming skills to catch up.
- Amy
At 08:22 AM 8/11/97 EDT, The Wrights wrote:
>----------------------------Original message----------------------------
>Here I am again as promised in my "wheel shaking" e-mail. Now I have a
>technique question. I have had a terrible time with trimming. I think
>it is one of the things that keeps me from persuing pottery as a primary
>source of income. I have tried and tried and tried. I probably would
>have a huge pile of thrown ware, except for having to trash pieces
>because I footed them off center, trimmed through the bottom, warped the
>top rim trying to press clay around the piece to keep it from moving
>while I'm trimming the bottom sides....to put it simply AAAAAAAH!!!!!
>
Evan Dresel on thu 14 aug 97
One thing that hasn't been mentioned yet is to examine the pot before you
trim. Run your fingers along the inside and outside profile if possible and
feel where the thickness is and where the curvature changes. Think about
where the foot needs to be for that pot. Get to know it before you start to
trim -- then follow everyone else's advice.
Good luck.
-- Evan in hot W. Richland WA wishing he'd signed up for both sessions of
Vince's ancient clay workshop
Daniel Turnell on fri 15 aug 97
When Ever I turn My peices The first thing I do is check how dry they are,
If the rims are still bendable I leave them alone, If their still "Sticky"
I leave them alone. If the pot is none of these, Then I throw a pancacke of
clay on the wheel. ( just like throwing a plate) Then I put concentric
circles on it with my wheel moving ( I like to move it fast when I do this)
whith the tip of my potters rib; or if you like to call it, a scraper, then
I use my scraper. Try not to use a ribbon tool and cut the circles into it,
It just makes a mess. Then line up your pot with the circles...push down on
it... then start turnin'
This only works with open faced, wide rimed pots. If your neck is to thin
then it probably will not work
you could probably still use the thumping technique that everybody else
described
good luck and happy potting!
D.E.T.
Ron Roy on fri 15 aug 97
Holding the pot (on the wheel) with your fingers and pushing on the pot
with your thumbs will tell you how thick the clay is. If the clay is still
too thick it won't move, if it just moves a little then you can stop. If
you want it thinner - keep trimming.
I know many of you will be wondering if this results in warpted and dented
pots - it will if you press to hard but - Clay has a little flexability
when it is "right" for trimming (many say cheeze hard) so when you have
learned how hard to press it works like a charm. I've been doing this with
my porcelain for 15 years now - a great way to get even walls and bottoms.
I must also add - especially when trimming porcelain - to use a sharp tool.
I belive a round wire tool requires too much pressure.
It is important to centre the pot so that the general area which is going
to be trimed in on centre - not the rim.
I can teach anyone to tap to centre - well almost anyone. The most
important things to remember - go slow at first till you learn when to tap.
The most important part is to get the tapper (your finger) off the pot
instantly. Its not a tap as much as it is a flick - more wrist than
anything else - you certainy can't do it with your arm.
The other part is learning how hard to tap - if it's way off centre then
tap harder but as you get closer to centre lighter and lighter. When I was
learning to do this - it was the only time it happened - I did look up
occassionaly to find the room turning.
Ron Roy
Toronto, Canada
Evenings, call 416 439 2621
Fax, 416 438 7849
Studio: 416-752-7862.
Email ronroy@astral.magic.ca
Home page http://digitalfire.com/education/people/ronroy.htm
John Harlow on sat 16 aug 97
> This only works with open faced, wide rimed pots. If your neck is to thin
> then it probably will not work
For bottle shapes or pots with a smaller rim than base I
use collars glued to wooden batts which clip on the wheelhead
I use for batts. The collars are effectively thick-walled
pots with wide bases in a variety (4 is enough) of diameters
biscuited. They're great time-savers once made and of course
don't degrade with use as a clay collar would.
----
/ / \ pot upside down
/ | |
\ /
+ \ / +
+ \ / +
+ \ / +
+ > < + bisque collar
+ || +
+ +
++ ++
+++ +++
====================== wood batt
###################### wheelhead
###
###
Hell, I'll start a 'useful tips' section on my website and mail
clayart when it's done! Watch this space!
John
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