Vince Pitelka on sun 20 apr 97
>I need to evenly band bowls that don't always come out the same. None of my
>brushes work very well -- the irregularities in the ware make the lines vary
>too much in thickness.
>
>Any ideas on gizmos that have a reservoir of pigment and a consistent line
>pattern?
Jeff -
I know of nothing which will work on an irregular surface any better than a
brush. I have had excellent luck using a brush to apply very consistent
banding on very rough clay surface. I suppose it depends on how deep your
pattern or texture is, and whether the shape of the vessel is altered at
all. Obviously, using a banding wheel and brush to get consistent, even
banding around a form will work well only if the form is quite round and
symmetrical at the point where you are banding, and the surface is not too
deeply textured.
For banding with slips or oxide/water mix I use good-sized East Asian
bamboo-handle brushes with good reservoir capacity (wet brush-head 3/4" to
1' maximum diameter, tapering down to fine point) for banding with slips on
leather-hard greenware, and with oxides in water on bisque-ware. It is
essential that the slip or oxide-mix be the right consistency. For this
purpose I use strongly tinted opacified slips, which would not be suitable
for thicker applications like slip-trailing, feather-combing, or marbling.
For example, if you apply rutile, cobalt carbonate, or iron oxide brushwork
underglaze on bisqueware, the glaze will usually crawl away from the oxide.
But if you use an opacified slip on leather-hard greenware, with up to 8%
rutile, up to 7% cobalt carb, or up to 25% iron oxide, watered down
considerably, it will flow on very smoothly, and subsequently the glaze will
not crawl. Some people add a little cmc gum or glycerin to make the mix
flow on even more smoothly. I have tried this and it does help quite a bit.
Another thing that often helps is to mist the surface with a spray bottle
before doing your banding. When banding with slips or oxides, if the medium
does not flow on smoothly, it can usually be attributed to a mixture which
is too thick, and/or a surface which is too dry.
When banding with oxide/water mixtures on bisqueware or on a dry unfired
glaze surface this problem is compounded. But again, if you use a mixture
which is thinned adequately (and colored more strongly to compensate), as
long as you mist the surface with water, or brush some clean water on first,
you should be able to get good, even, smooth banding. Again, a little cmc
gum or glycerin added to the mix might help. Dissolve your cmc gum in hot
water to get a thick gel, and then just add a little of that to any slip,
stain, or glaze when you are having trouble with flowing or adhering.
A note on those East Asian brushes - avoid buying bamboo-handle brushes
which say ANYTHING on them in English, and avoid the ones with the plastic
ferrules holding the bristles in place. Look for the ones which have thread
binding around the bamboo very close to the bristles. This prevents the
bamboo from splitting. If the string starts to unravel, remove it, replace
it with new binding using nylon upholstry thread, and seal it on with marine
spar-varnish. When properly cared for these brushes will last indefinitely.
If you want to get the most life out of them, don't EVER leave them standing
in liquid for any length of time, always clean them thoroughly, and allow
them to dry with the bristles shaped to a point. And if you know anyone
going to China, Korea, Vietnam, Thailand, etc., give them fifty bucks to
spend on brushes. You'll have a lifetime supply.
One final note - successful banding depends greatly on the quality of your
banding wheel. A hand-turned banding wheel only works well if it is very
heavy and and has good bearings and thus can develop steady momentum. Such
banding wheels tend to be very expensive. But if you have a potter's wheel
you already have an ideal banding wheel for such work. I am fortunate in
that I have an antique Garrard direct-drive turntable which I have adapted
to serve as a power banding wheel. It works great. A friend I know made a
similar one from a ceiling-fan motor. Either of these can be stopped or
slowed by hand without damaging the motor, unlike a normal motor.belt-drive
setup.
Good luck.
- Vince
Vince Pitelka - vpitelka@DeKalb.net
Phone - home 615/597-5376, work 615/597-6801
Appalachian Center for Crafts
1560 Craft Center Drive, Smithville TN 37166
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