search  current discussion  categories  techniques - cracking 

crack repair

updated sat 20 feb 10

 

Lee Love on thu 18 feb 10


A guy in this neck of the woods, used gold or gold colored luster to
cover small blemishes. Would this work? Or would you have to fill
with a neutral luster and coat with gold luster?

A friend of mine used to get her gold luster from a friend in
Japan who would never charge her. After he passed away, she ordered
for herself for the first and last time.

--
Lee, a Mashiko potter in Minneapolis
http://mashikopots.blogspot.com/

=3D93Observe the wonders as they occur around you. Don't claim them. Feel
the artistry moving through and be silent.=3D94 --Rumi

Bruce Bowers on thu 18 feb 10


Hi All,
I am wondering if anyone has had first hand experience with Kin Tsugui,
Japanese lacquer and gold repair of cracked pottery.
I know that the original way of performing repairs of this type is to lay
down layers of Urushi lacquer and then dusting gold powder over the
top....then burnishing.
Urushi lacquer, in pen form, is about $1150!.......and gold....forget about
it.
Therefore, I am interested in whether anyone has done repairs of this type
using gold leaf and sizing for gold leaf. If so, does the finished job
look cheesy?
I have a few small cracks in woodfired pots that I would like to accentuate
in this way.
The cracks are pretty small and could easily be filled and smoothed with PC
epoxy prior to any gold work.
Usually, I just let cracks show themselves as part and parcel of the pots
interaction with nature, but another approach would be nice to have, too.
Any advice would be great.
Bruce Bowers
_www.bowerswoodfireandpics.com_ (http://www.bowerswoodfireandpics.com)

Mike on fri 19 feb 10


Hi Bruce,

Trust me when I tell you you do not want to use real urushi. Unless
you're one of the few who isn't sensitive to urushiol containing plants
like poison sumac, etc... And urushi requires fairly strict humidity
and temperature conditions bet met for it to cure properly.

Filling the cracks with epoxy (like you mentioned) is the first step to
the process. Those 2 part putty sticks are really convenient for this
but get the kind that allows for some working time. The 10 minute stuff
is just too fast.

After it's filled and sanded/smoothed, find a non urushi lacquer (I use
one called shin-urushi, or 'new-urushi', which will not cause allergic
reactions, which dries fairly quickly, and which can be thinned with a
standard thinner. It's used mostly here by folks who make and repair
fishing poles). Anyway, depending on the surface to repair, you could
probably use a number of 'store bought' lacquers.

There are three options to applying the lacquer and gold.
1. apply the lacquer first, use a cotton ball or makeup brush (less
waste with the makeup brush) to pick up the gold dust and drop it onto
the tacky surface. The gold will sink in. After it's had a chance to
dry a bit and not be so tacky, tamp or brush away the excess. polish the
surface after it has dried fully. The tool of choice for burnishing
urushi gold repairs is the front tooth of a large tai (sea bream)
affixed to the end of a stick or still attached to the jaw. (Seriously,
I'm not making this up.)

2. take a few drops of lacquer and thin it with a drop or two of
thinner. then mix in the gold powder until you have a nice thin gold
paste (like warm honey). Get a very fine brush and go over the crack
line. Do it in one stroke if possible, DO NOT go over the same place
more than once. Only make as much as you will use because otherwise it's
a real waste.

These first two methods have the advantage of the gold being in the
lacquer not just on the surface. So it doesn't wear away so easily.

3. Apply the lacquer, then apply gold leaf over the lacquer. Tamp it
down well with something soft (a cotton ball). clean the edges after the
lacquer has dried. Masking the area with tape ahead of time works well.
This method is better for wide areas to be repaired, not so good for
thin cracks. Also, it's easy to scratch away the surface color. With
this method sometimes another layer of lacquer is applied over the gold
to protect it.

One alternative to gold dust is mica dust. It's sold in some ceramic
stores around here as a cheap alternative to gold for over glaze
painting. Problem is the mica does not really polish up to much of a
shine, though it comes in a range of colors. Also, depending on the
piece to be fixed, silver is an option. It is far cheaper, and the
tarnished silver surface might actually work better than gold on some
pieces.

I hope this helps,

Mike

Mike
in Taku, Japan

http://karatsupots.com
http://karatsupots.blogspot.com

Kiln Building Workshop, Oct. 15 - 22

http://karatsupots.com/workshop2010/workshop2010.html
http://karatsupots-workshop.blogspot.com/


(2010/02/19 9:15), Bruce Bowers wrote:
> Hi All,
> I am wondering if anyone has had first hand experience with Kin Tsugui,
> Japanese lacquer and gold repair of cracked pottery.
> I know that the original way of performing repairs of this type is to lay
> down layers of Urushi lacquer and then dusting gold powder over the
> top....then burnishing.
>
>
>

Lee Love on fri 19 feb 10


In John Britt's list of shino glazes, from his recent shino workshop,
Shaner crackle Shino Slip is listed. It is recommended to heat the
glaze to 1100F, and then rub a 50/50% mixture of stain and frit or
gestly borate into the cracks, and then fire to cone 10.

If your crack is deep, maybe you could add some type of mixture to the
crack like this, and then color with gold enamel. You could choose
your temp.

Or, how about PMC, precious metal clay? This material is
very big in hobby circles in Japan. It might be interesting to used
to decorate or add rings etc to pottery.

--
Lee, a Mashiko potter in Minneapolis
http://mashikopots.blogspot.com/

=3D93Observe the wonders as they occur around you. Don't claim them. Feel
the artistry moving through and be silent.=3D94 --Rumi

Lynn Goodman Porcelain Pottery on fri 19 feb 10


I tried a couple of times to cover up flaws with gold luster--all it
does is highlight the flaw and make it look worse. Better to call the
piece a second and move on.


On Feb 18, 2010, at 9:52 PM, Lee Love wrote:

> A guy in this neck of the woods, used gold or gold colored luster to
> cover small blemishes. Would this work? Or would you have to fill
> with a neutral luster and coat with gold luster?
>

Lynn Goodman
Fine Porcelain Pottery
Cell 347-526-9805
www.lynngoodmanporcelain.com

Lee Love on fri 19 feb 10


Butch Holden is the potter that uses the luster technique. I can't
find pieces here, but here are some examples of his colorful work:

http://lakecountryjournalonline.com/node/122

--
Lee, a Mashiko potter in Minneapolis
http://mashikopots.blogspot.com/

=3D93Observe the wonders as they occur around you. Don't claim them. Feel
the artistry moving through and be silent.=3D94 --Rumi