Please keep in mind that any wet process is a harsh torture and
potential damage for each fiber. They are made to stay dry. The most sensible
part of a weave are the dye lakes 1 (as opposite to vat dyes
et.al.).
In order to understand the basic problem of antique
washing please imagine the following situation: in a wild, big garden,
forgotten since long time, there is a wall made from bricks. The bricks are
spotty. Lichens grown on them, even mosses. Residues of evaporated salt is
visible on the surface of the bricks. The mortar, that once kept the bricks
together, is corroded. A certain part of the mortar has fallen down. If one
scratches some spots, where the mortar seems to be intact, it is easily
removed.
In case one would try to clean this wall by means of a high
pressure - hot water cleaning apparatus for sure some parts of this wall would
be clean. Some parts would be smashed under the high pressure. Even where the
mortar seems to be intact , but is in fact partly corroded though invisible, it
would be rinsed out. As a consequence quite a lot of the bricks would drop out
of their context, immediately or later. Therefore some parts of the wall most
likely would collapse.
It would have been bettr first to remove the
corroded mortar and replace it immediately by fresh one. Some days later this
fresh mortar would be hard and resistant. Then it would be possible to clean
the whole wall thoroughly. It would be kept intact and would look moreor less
clean, then. That it is an old wall would remain perceptible.
Antique
textiles should be cleaned according to this principle. They have been made
using mortar. Substances that can be compared with the mortar of this above
given example exist in deed:
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The first step of treatment should be to repair the damages caused by
oxidation, but they cannot be completely reverted. This result of us is
confirmed by a new research reports on how to treat microbials stains on
antique papers 4 . Then the dye lakes must be repaired.
After this is done the textile can be washed. Preferably „soft" type of
tensides (detergents) should be applied. Alkyl sulphates or even alkyl ether
sulfates must be avoided because of their strong defattening properties.
Certain tensides tend to form chelates with polyvalent metals (all ethylen
oxide adducts). They attack the fastness of dye lakes and should not be used
therefore.
Against common knowledge soap is not an adequate
tensid to wash antique textiles made from wool. To achieve a proper cleaning
action with soap the fluid must be quite alcaline. Wool absorbs acids and
alcaline substances strongly. They cannot be removed with cold water and remain
in the wool causing long term damage. The optimal pH for wool and for human
skin is pH 5,5.
Finally the textile should get a
refatterning treatment using exclusively natural substances. This claim
excludes lanoline with is manufactured using mineral oil based waxes. Under no
circumstances one may use synthetic substances in order to improve the lustre.
Many of them adhere irreversibly as it is the case with the new synthetic
silicone substances.
If one is limited to use exclusively natural
substances for refattening the consequence is an antique textile with a good
lustre of excellent dyes and wool but with a lackluster sheen where their
quality would be mediocre. If silicone is applied a stark glare dominates all
areas of this textile. But silicone adds this glare even to grey concrete.
It is said that an archaeological excavation is the only scientific
experiment that cannot be repeated. The same is true for washing antique
textiles, especially if they have been stapled somehow somewhere in the Orient.
In case they are submersed in a first step into soft water and in case they are
washed using a special soft tenside nevertheless all dyes, which are not
fixed good enough by means of the above mentioned processes,are
irreversibly removed. Perhaps the textile would be clean then. Regarded
as a piece of art it is heavily damaged, if not destructed.
On
request we are ready to communicate which textiles, whose condition before and
after such treatments we could check with our own eyes, have been
„improved" by this way in the last years.
For a critical evaluation it must be noted that one has to achieve a
balance between factors that may oppose each other when an antique wash is
done3 :
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The system used here puts the priority on the last two aims, in case of
conflict on the expense of the first one.
1 A state of the
art treatment of an 18th century "Konya" carpet with an open, bright, lucent
yellow would be like this: first a HPLC with Diode-Array-Detection analysis of
the dye, whether it is made up from (a) flavones or (b) flavanol-glucosides. In
case (b) under no circumstances even 1 drop of water should be applied: the
bright yellow would change irreversibly to a dark, matt ochre-brown- yellow -
as is has happened often in the last 15 years.
2 In fact
there are more different molecules in cotton and linen than just cellulose.
3 Attention: in case a C14-radiocarbon dating
is planned the natural auxilliaries used here may interfere with that. The
result would be too „young" then.
4 Koch, Beate,
Trick, Iris & Vohrer, Uwe (2000): Stopp dem Buchzerfall. Spektrum der
Wissenschaft, 4 , 2000, 85 - 87. - This is the latest high technology approach
for paper conservation. Realized with different tools this is exactly the same
kind of treatment that KÖK uses since about 15 years for securing antique
textiles.