Jeff Longtin on fri 12 jul 02
Gang,
Have a few plate forms that I want to make thin and I'm thinking about my
alternatives. All this talk of paperclay makes me wonder when did paperclay
replace nylon fibre as a clay body additive? If I recall the benefit of nylon
fibre was that upon burning out you had fibre/resin residue left in your clay
to aid in strengthening. It now sounds like all you have left with papeclay
is complications, iron, ash, etc.
Does anyone know the big difference between the two and the pro's and con's
of both?
Years ago I used nylon in a slip-casting body and found it to be allright
except that the backside to plate forms had a very pebbled texture. As I
didn't see an improvement in warping I chose not to continue its use. With
the forms I'm making now I definitely need something to counter cracking.
Thanks
Jeff Longtin
iandol on sat 13 jul 02
Dear Jeff Longtin,=20
Paper fibres were being used as an additive, strengthening clay, long =
before Nylon was invented.
It may interest people to know that because plant fibres are hollow =
tubes and clay particles are extremely small by comparison that =
capillary action draws fluid clay into the fibre. So fired paper clay =
may be stronger and denser than we believe it is.
Best regards,
Ivor Lewis
vince pitelka on sun 14 jul 02
> Have a few plate forms that I want to make thin and I'm thinking about my
> alternatives. All this talk of paperclay makes me wonder when did
paperclay
> replace nylon fibre as a clay body additive? If I recall the benefit of
nylon
> fibre was that upon burning out you had fibre/resin residue left in your
clay
> to aid in strengthening. It now sounds like all you have left with
papeclay
> is complications, iron, ash, etc.
Actually, with nylon fiber the advantages are only in the wet and bone-dry
stages. In firing, the nylon combusts completely just like paper pulp. But
the normal addition of nylon fibers is very small - usually only a loose
handful per 100 pounds of clay, so there is a much smaller amount of carbon,
ash and porosity.
There is no fiber additive that I know of that remains to provide greater
strength in the fired clay. Even fiberglass or ceramic fiber (which are
carcinogenic and severe skin irritants and should never be used in clays to
be worked by hand) will interact thermochemically with the other materials
in the claybody during the firing, and will cease to work as strengthening
fibers.
Best wishes -
- Vince
Vince Pitelka
Appalachian Center for Crafts
Tennessee Technological University
1560 Craft Center Drive, Smithville TN 37166
Home - vpitelka@worldnet.att.net
615/597-5376
Work - wpitelka@tntech.edu
615/597-6801 ext. 111, fax 615/597-6803
http://www.craftcenter.tntech.edu/
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