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question about terra sig/shine

updated sat 5 aug 00

 

Cindy Strnad on wed 2 aug 00


Shelley,

Actually, the acrylic floor wax is much more subtle than you might imagine.
I thought the same thing, but I did try it, and it produces a nice, subdued
sheen--as long as you don't apply three coats or something. One thin coat is
sufficient, if needed.

Shelley Corwin on wed 2 aug 00


re mark's floor wax-hmmm-old indian trick, eh? those tipi floors must have
been something to see! paste wax or carnuba, then buffed, will be a bit more
subtle and does the same thing. if you really want a deeper look, use
jewelers rouge on a wheel buff. wax only works on burnished, smooth area, it
sticks in the rough crannies and looks disgusting.

Gavin Stairs on thu 3 aug 00


At 12:47 PM 8/3/00, shelly wrote:
>... the phrase old indian trick just got to me! cultural
>adaptation, assimilation, etc. shelley

Lot of old indians out there. Lot of tricks, too. Tricky
indians. Surprising how young some of those old indians are.

I have a rant in me, wants to jump out and say, "That's not right! Using
wax to fool those unsuspecting tourists!" Problem is, it's real
authentic. Not the floor wax, mind you, but using organic finishes and
fillers to waterproof and decorate pots of open fired earthenware. I'm
sure even the Romans did it. Crafty old indians they were.

There's nothing very mysterious about the terra sigilata finish. It is
shiny because of the plates, as noted. The deflocculation and decanting
tricks are to select only clay particles that are sufficiently small and
thin (i.e., the ones that don't settle out fast). So the burnishing lines
them all up nicely.

The finish is destroyed when the ware is heated up enough to remove most of
the water of crystallization, because when you take out that water, clay
recrystallizes, and the little plates turn into little blobs of random
orientation. The interesting question is, what is holding things together
before that temperature? That is what we call immature fired clay. I
suspect that what happens is that the recrystallization happens over a
range of temperatures, depending on the local distribution of fluxes and
clay particles. Or perhaps because the clay particles recrystallize from
the edges inward over an extended range of time/temperature. I don't
know. But the true terra sig is fired to some point midway through the
dewatering phase of maturation. Well before the good glass forming phase.

I've not seen a good, detailed discussion of this recrystallization
process. However, if one were to dig deep enough in the academic
literature, one would be sure to find something about it. It's the kind of
niggling detail that intrigues such people, and which often ends up leading
to breakthroughs in technology.

Gavin

Richard Jeffery on thu 3 aug 00


> >re mark's floor wax-hmmm-old indian trick, eh? those tipi
> >floors must have
> >been something to see! paste wax or carnuba, then buffed,
> >will be a bit more
> >subtle and does the same thing. if you really want a deeper
> >look, use
> >jewelers rouge on a wheel buff. wax only works on
> >burnished, smooth area, it
> >sticks in the rough crannies and looks disgusting.
>
If you do use wax and it does stick in the crannies... you can melt it in
with gentle heat. Do it all over, and you will lose the thin layer of wax
on the smooth parts, which is no good. Try using a small blowtorch/brazing
torch, with a gentle flame and just waft it over the wax - you will see it
sink in. You might need to touch up the surrounding smooth areas if you
overdo it.

Have you ever tried using a buffing wheel to get a decent high shine (if
that's what you want)? They are used by cabinetmakers - looks a bit like a
round scrubbing brush, fits in a power drill. Don't try to make one from
that description unless you KNOW the bristles won't shoot out at 1500 rpm -
and use gloves and eye protection if you buy one. Use it after you have
removed the excess wax with a cloth (old towels are good - not quite as
abrasive as fine steel wool), then use the wheel all over to buff the piece.
Furniture tends to stay still - with pots it might be easier to fix the
drill in place on a bench and move the pot into and over the brush. You
need to keep it moving all the time to avoid hot spots, and beware of any
deep crannies that might snag and pull the pot out of your hands. Small
fragile extrusions might cause a problem, too....

Richard
www.TheEleventhHour.co.uk

Shelley Corwin on thu 3 aug 00


along the acrylic floor wax idea-i sometimes use diluted acrylic medium, or
plain elmers glue. non toxic and cheap! this way you can use a pit fired
pitcher or eat out it. the phrase old indian trick just got to me! cultural
adaptation, assimilation, etc. shelley

Gayle Bair on thu 3 aug 00


Shelley,
I have used Shoe polish on rough
incised pieces. I polished them with
a piece firm foam and they looked great.
The dye in the shoe polish gave depth and
rich colors. My favorites were a combination
of cordovan and brown.
One thing to watch out for is fading when
exposed to direct sunlight.
Gayle Bair- Bainbridge Island, WA
where most of the year direct
sunlight is definitely NOT a problem



>snip
wax only works on burnished, smooth area, it
sticks in the rough crannies and looks disgusting.

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James Bledsoe on fri 4 aug 00


I once met an "indian" who lived all his life in Los Angeles at his art show
he exhibited genuine indian artifacts, his common every day cloths, levis
and nikes and Mc Donald's. He was a real indian and every thing he did or
had was real indian stuff.

by the way do you all know the milk trick for sealing porous bodies? yah
just rinse and let the milk sour in vase. The casing will seal that puppy
tight

old human trick

Jim

>>
Lot of old Indians out there. Lot of tricks, too. Tricky
Indians. Surprising how young some of those old indians are.

I have a rant in me, wants to jump out and say, "That's not right! Using
wax to fool those unsuspecting tourists!" Problem is, it's real
authentic. Not the floor wax, mind you, but using organic finishes and
fillers to waterproof and decorate pots of open fired earthenware. I'm
sure even the Romans did it. Crafty old indians they were.
<<