Funori

Robert Proctor <wpfineart [at] artconservators__com> writes

>... 0.1 gram of the dried
>material was then redissolved in 10 mL distilled water and warmed in
>a small bain de marie. After about 2 hours I noticed it had turned
>an orange-pink color! Has anyone else seen this or have an
>explanation? As one may imagine, I am hesitant to ever use funori
>now.

In our experience, the colour pink-orange in a funori mixture may
well be associated with mold but in that case, one would expect the
presence of a very foul odor as well. Without a clear description of
what transpired in the lab, it is not obvious what has happened to
the samples.

We have been doing quite a bit of experimental work with funori.
Material purchased from Talas and from University Products was
prepared and produced an adhesive with the required characteristics
for adhesion of rice paper to wood as is one of many typical uses of
the material in Japanese crafts. However, the level of material
purity and the need to be fully aware of all the ingredients present
in concoctions used in the conservation of works of art is such that
this material is probably/possibly not a good starting point. There
is no documentation available for either product. One other problem
with both is that we don't know how the raw material was treated in
Japan or wherever in the world it might have been harvested, and we
don't know how it was bleached.

The Jun Funori product (translated as Pure Funori) made by Lascaux
is a western attempt to industrialize the craft process of
extracting the polysaccharides from the seaweed. They are apparently
after a "one size fits all" convenient adhesive with the remarkable
"no tide lines" characteristic of all funori fixatives. The
resulting substance has apparently been less than 100% consistent
and as a commercial producer, Lascaux is less than forthcoming about
the precise admixtures used in bleaching or the methods employed in
the purification process.

The traditional harvest and extraction methods provide a material
with the characteristics required for its uses in the traditional
Japanese crafts. They may not produce exactly what is needed in the
fine art conservation world. At the very least, the methods and
materials need to be carefully examined.

We started our research in Japan. Our plan is to continue to
purchase raw unbleached funori of two different types from a family
firm in Fukui City. They have been agents in the funori trade for
well over a hundred years. The location of the harvest off the Five
Islands off the Shizuoka Prefecture in Japan is well documented. The
first type is fukuro (pouch) funori, with long flotation airbags and
a higher concentration of polysaccharides. It is mauve in color. Ma
funori, another more commonplace type, harvested nearby is deep
purple. To give an indication of how deeply rooted funori is in the
sophisticated Japanese craft culture, we are told that the weavers
of the best silk for kimonos, prefer to lubricate the weft threads
on the loom with a funori lubricant made of a combination of these
two types of seaweed.

One of the problems with the industrial production of funori
adhesives is that the raw seaweed varies so much from year to year
and place to place. The polysaccharide content in the seaweed
apparently goes up and down from year to year. The local experts we
have spoken to in Japan believe the climate change issues are at
play in this. We don't know.

Our plan is to establish a methodology for the extraction of
polysaccharides from different species of funori of known origin and
provenance. The material will ultimately be identified by year of
harvest for instance, 2013 or 2016 with a fairly precise location
identifier. As we get them currently, both species are simply rinsed
in fresh water, sun dried and packaged in heavy poly bags. They both
smell and taste like the ocean when we get them.

We are experimenting with extraction techniques and hope to be able
to provide a constituent analysis of the material that is extracted.
The idea would be to produce a known quantity of adhesive with
precisely known characteristics and a provenance that can be shared
with conservators. The finite supply of any given annual yield would
be tested and packaged as a dry mixable powder with published
performance characteristics.

We arrived at this line of research after using both the Talas and
University Products funori offerings to stabilize very friable
tempera painted ceilings at Glanmore National Historic Site a
splendidly decorated historic house museum in Bellville Ontario.

We would be very interested to share our experience with others who
are using funori in architectural conservation.

Rod Stewart
Masumi Suzuki
Historic Plaster Conservation Services Limited
26 Barrett Street,
Port Hope
Ontario L1A 1M7
Canada


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                  Conservation DistList Instance 26:11
                 Distributed: Saturday, August 4, 2012
                       Message Id: cdl-26-11-002
                                  ***