TAONGA

Kaea, Issue 2, 1 March 1980, Page 16

TAONGA

Taking care of your

In the course of his work as senior technical officer for the Anthropology Department of Auckland University, Karel Peters has come across many unfortunate cases of deterioration or neglect in prized possessions such as carvings, piupiu, cloaks and whakapapa books. Often, this damage could have been avoided with proper knowledge and care. In this article Karel gives us the benefit of his experience and knowledge to explain how best to look after our taonga.

Over the past years I have been engaged on conservation projects associated with Maori communities, working on meeting houses, pataka, wooden headboards and so on. In a number of these cases the deterioration could have been easily avoided if the owners had known how to recognise the deterioration processes which had been going on for quite some time.

I don’t propose to give recipes for the treatment of artefacts. The science of conservation is too complicated to allow discussion of treatments here, and in any case what is a good treatment for one object could be dangerous for another even though it may be made of the same materials. Rather, I will give the reasons for various cases of deterioration and explain how these can be avoided. Good “housekeeping” is most important, and the saying “an ounce of prevention is worth more than a pound of cure” is particularly apt. The collections held by Maori tribal communities and private families contain a great variety of materials, ranging from meeting houses with wooden carvings, painted surfaces, tukutuku panels, etc., to such items as cloaks, piupiu, headbands, kits, mats, photographs, paintings, watercolours of ancestors, books, letters, drawings. All these articles are made of organic materials wood, natural textiles, feathers, paper, etc. which are affected by changes of the environment. They are hygroscopic, i.e. moisture-sensitive, and either absorb or release moisture, thus shrinking or expanding. These changes are small but nevertheless they take place and, because the deterioration is slow, to the untrained eye there is little to see. Unless well-documented records are taken, people are lulled into a relatively “safe” feeling. In summer when temperatures are high we get excessive dryness, shrinkage sets in and with that cracking and warping of wood. Paper becomes brittle; textiles, basketry and fibrous materials (tukutuku panels) are weakened by this drying out. In winter excessive wetness causes swelling and warping of wood. Paper, textiles and basketry are in danger of mould or fungi growths, and salts absorbed in these materials will crystallise and thus expand, causing damage to the natural structure of the materials.

Light, which contains ultra-violet radiation, causes damage particularly to textiles, paper and all organic materials in which colour is important. It causes textiles to rot and colours to fade. One has only to think of cotton curtains which have been hanging in front of windows collecting sunlight for a long period of time.

In cities and built-up areas air pollution brings soot, dirt, and chemical components into the environment and these also contribute to the deterioration of artefacts.

As well as these environmental factors which will affect the collections and articles you have, there are pests such as rats, mice, moths, cockroaches, silverfish, and probably possums. These pests are not slow in destroying artefacts and I have seen irreparable damage done by them in a very short time when they have been left unmolested.

You might well say that I have painted a very bleak picture. However, with a bit of good housekeeping a lot of these general causes of deterioration can be avoided. I will divide the materials into three groups: wood, textiles, and paper; and describe in layman’s terms the main reasons for deterioration, and methods such as correct storage to prevent this deterioration.

Above The head of the figure at left. Concrete extends from crown to chin. Deep cracks have appeared, and only the stainless steel headband holds it together.

WOOD

Unless precautions are taken to guard against biological attack, dry rot and wet rot, wooden artefacts can suffer serious damage by the growth of fungi or by attack from borer. Carvings made in timber are not always tanalised. They are usually set in concrete or in the ground and in most cases it is there that the rotting starts. The timber is kept rnoist for long periods of time by the water held in the concrete and rot sets in, the wood gets soft, the mechanical strength disappears, and eventually the wood will crumble at a touch.

Borer attack is serious and if allowed to go unchecked can do great damage. The only effective way of dealing with this problem is fumigation, and this should not be done by borerbomb, but by a reputable professional firm which deals with fumigation. It should be followed by spraying with an insecticide. For portable artefacts this spraying is not

necessary if they are stored properly, but in the case of buildings it is advisable. It is not always possible to do this however, particularly with decorated houses. Then one has to rely on fumigation only, but as soon as new borer infestations are shown up again by fresh borer dust, fumigation has to be carried out once more.

A word of warning: The use of borerbombs is not advisable as these have practically no effect at all on borer. They only affect the borer fly in flight and, as borers fly for about two months, it means in practical terms that one has to let off bombs over two months, and keep the smoke in the building for twenty-four hours each time. Even then the larvae inside the wood will not be affected and they will go on destroying the interior of the wood.

Wooden carvings outside buildings are exposed to the elements and invariably develop cracks due to stresses brought about by the changing elements such as temperature and humidity. Wooden carvings like the poupou, pou-mua and amo are usually set in the ground and/or concrete, and it is there that deterioration sets in. They are all also subjected continuously to rain, dust, sun, etc. The dust settles into the cracks and holds the moisture for long periods. Bacteria start to grow and rotting sets in slowly but surely, and over a long period of time the timber will lose its strength: although looking good on the outside, one day somebody will be able to put a finger through its protective coat of paint! Thus areas to watch are: where the carving enters the ground or concrete, and the various cracks. Also, by tapping the wood one can observe differences in sound: the deteriorated areas should sound hollow whereas sound timbers have a solid sound.

If there is deterioration, ask for advice; do not attempt a do-it-yourself job. I have seen too many “jobs” done which have caused more damage and created real difficulties for the restoration of the object. In one case concrete was poured into the head of a wooden figure and resulted in a core of rotted timber down the total length of the figure. The concrete held the moisture of rain and bacterial growth was prolific, causing the rot to spread throughout the figure. In another case concrete was poured around rotted timber to hold it in shape, but in fact this process accelerated the deterioration. PVA glue has been used to “preserve” wood carvings, but this is the wrong material and actually causes destruction. Again, do not experiment, but ask advice.

TEXTILES

Cloaks, piupiu and other fibrous materials are usually kept indoors in cupboards or drawers and sometimes hung on walls. Ideally they should be kept in controlled conditions of temperature and humidity. This is practically impossible in private collections and in meeting houses, but there is a lot that can be done to extend the life of these materials. Storage and handling are of the utmost importance.

I witnessed an incident one night when a person who gave a talk brought with him various cloaks with feather borders, two of which were completely covered with kiwi feathers. The cloaks were folded into a smallish suitcase and when taken out were shaken, and consequently feathers flew everywhere. The storage and handling was wrong. Ideally textiles, particularly ancient ones, should not be folded. The fibres become very brittle due to age, and folding will break them and tears will appear in time. Exposure to the sun will not restore life into these fibres, although I was assured by the owner that that was what he did to “preserve” them. I have already pointed out what excessive light does to these materials.

Textiles should be rolled up on cardboard rolls which have been covered by polythene to prevent acid from the cardboard entering the textiles, and they should be interleaved

with acid-free tissue paper, which is available from paper merchants. If they are hung up, make sure that no metal or wood comes into contact with the textile. Metal oxidises in humidity and causes rust stains; wood also contains acid which will damage the fibres. When a coat-hanger is used, soft padding like foam plastic should be put over it so that the sharp edges are taken care of and do not cut into the fibres. If this is not done the weight of the whole garment is put on the two sharp edges of the hanger. A plastic drycleaning bag should be put over the whole garment to keep the dust and dirt off. Tie both ends to keep insects like moths out. If textiles are to be folded in a drawer, change the folds regularly so that there are no permanent folds. Again, the folds are the places where the fibres break easily after time. Piupiu can be stored in an old nylon stocking; this keeps the dust off and at the same time holds the piupiu together and lessens the risks of damage during handling.

All storage areas for these articles should be kept dry and air should be allowed to circulate, as stagnant air invites fungi and mould to grow. You should also have some camphor crystals in plastic bags with holes so that the fumes can circulate. However, do not let the crystals come in contact with the textiles.

When displaying capes or cloaks do not use nails, pins, etc., to hang them up; the weight of the cloak will do damage to the areas where the pins have been put through and will cause tears. The best method is to drape the cloak over a frame covered by polythene sheeting.

PAPER

Photographs, record books, letters, watercolours, etc., come into this category. One of the main problems with these materials is acidity from acid inks, the paper-making processes, and acidity absorbed by the paper when it is kept

in a polluted environment. In these cases paper starts to go brownish in colour and becomes brittle. Light is chemically active and can cause ink to fade and paper to decay through over-exposure to the ultraviolet radiation present. Moulds and fungi are active when climatic conditions are damp and there is no air circulation. Silverfish are also very active and will eat their way over the surfaces of paper. They can be controlled by putting camphor crystals in plastic bags with holes into drawers or cupboards. Vapona insecticide strips can be used, but care must be taken as they can be harmful to humans. A good and safe way is to cut them into small strips and place these on polythene in drawers, etc.

In general, documents should be stored in a cool place which is reasonably dry, well ventilated and not too brightly lit. Photographs and watercolours should preferably not be displayed in bright light; the more subdued the light the better. Keep an eye on the materials and check the backs of drawers periodically to see if silverfish or other insects are active.

This is a very general article and is meant to make you aware of the various reasons for deterioration. If in doubt seek advice rather than experiment yourself. You will probably do more damage and make it more difficult for the experts to rectify this as well as do the proper conservation job.

For paper and associated materials ask advice from Mr J. Baillie, Conservator at the .Alexander Turnbull Library, Wellington.

For wood and meeting house projects, consult the New Zealand Historic Places Trust which has a Maori Building and Advisory Committee. Mr Apirana Mahuika is the chairman and Mr Cliff Whiting is a member. This committee I am sure is very keen to provide help and put you on to the other experts if necessary. You could also approach me at the Anthropology Department, University of Auckland, Private Bag, Auckland.