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Conserving Archives
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Part of the role of Local History Recorders is to ensure that interesting archives and objects relating to the past of their communities, are retained and looked after. In 2004 the association had an extremely useful workshop on this subject, organised by Lynn Morrison, the Conservator at Saffron Walden Museum. All Recorders have since then been given the following worksheet, a useful check list for others wanting to know how to care for precious documents of the past.
WORKSHEET: CONSERVATION OF DOCUMENTS & OBJECTS
Conservation is an ongoing process of learning, you need to know when to leave things alone and when to ask colleagues for advice.Emphasis is on preventive care, storing things properly can do a lot to save material from destruction. Protect objects till you can examine them, then decide if you can deal with it or if it needs someone more experienced. Give yourself space to work. Be aware some objects are harmful, e.g. there could be asbestos, or chemicals could have been applied in the past. If in doubt bring things to Museum to be tested to see if they are harmful to health, and handle with gloves and mask. Inhaling mould is bad for health. Buy dust masks, cotton handling gloves or gloves with a grip from pet shops. A box of 100 disposable plastic gloves costs only a few pounds from dental suppliers. Much free advice and help is available from your local museum.
PREVENTIVE CARE
The
aim of conservation is to protect against damp, heat, mould, insects = light,
temperature, humidity and pests + to
minimise the tendency of some
materials to self-destruct over time. Conservation focuses on what
objects are
and how to preserve it, e.g. metal is complex – each metal is
different and
needs different treatment.
LIGHT: You need low light levels to avoid fading. You can put a film over the windows to keep ultra violet out, or use blinds, or store in cupboards, boxes and drawers.
HUMIDITY: Objects react to
moisture, expanding and contracting all the time which is why
fluctuations
cause warping and cracking. Objects can be stable in most conditions
but mould
grows at high humidity (above 68%), which should be avoided. Relative
humidity
should be lower for metals, say 40% whereas organics prefer higher
humidity,
about50-60%.You can never completely
get rid of mould and
cannot totally exclude air and moisture from affecting your objects.
Roof
spaces are bad places to keep things due to roof leaks. Cellars are
usually too
damp. You can use a home dehumidifier, but remember
to empty the bucket
regularly. Museums use a thermo-hydrograph to give a picture of
temperature and
humidity in storage space over time. Meters cost
several hundred pounds,
but hygrometers are cheaper. A whirling hydrometer only costs
£20-£40.
PESTS: Vigilance and good
housekeeping are the best defence against pests, which are a big
problem if
left undisturbed – moths, silverfish, invisible book lice.
When you get a new
object quarantine it and examine carefully. If in doubt, or it is
obviously
affected, put it in a polythene bag in the freezer
– minus 30 degrees
for 3 days, or -18 degrees for a week, or -10 degrees for 2 weeks: this
kills
all stages of the pests and is better than chemicals. Freezing does not
damage
paper, photos, or even framed pictures.
Rodents – watch out for mice. Moths attack textiles. Woodworm can be seen by piles of powder under undisturbed wood objects, as well as flight holes – the answer is to freeze the objects. Woodlice and spiders don't eat things but they are an indicator of damp, so dry out the environment. Pests like it warm and damp – conditions to avoid.Booklice and silverfish are very bad for paper. Make the stores dry and cool and remember pests thrive in dark, undisturbed conditions, so keep cleaning!
PRESERVATION
Scanning and photocopying produce
lots of light on your object so only do it once. Write on the back of
the
object in soft pencil that it has been scanned, or keep a written
record.
Cleaning: Dry cleaning is best,
using a brush. Dust objects with a soft brush directing dust into the
nozzle of
a vacuum cleaner or use a soft brush attachment with muslin, netting or
tights
over it to stop bits being vacuumed up. Brush off mould, preferably
outside. If
necessary to use moistened cloths, use distilled water – a
dehumidifier
produces distilled water which can be used to wash things.
Photographs: Silvery tinge on
photographs indicates deterioration of the silver nitrate in the
emulsion –
there is no cure, so just photograph or scan it once and
don’t exhibit it in
the light. Curled up photos should be stored flat which might improve
them. Avoid
handling by storing photographs in a Melinex sleeve.
Documents: Paper can be flattened by relaxing first in a damp place for a short while, then weighted, then stored in an archival grade Melinex sleeve – don’t iron it and don’t use sellotape. Copies of documents should be treated with the same care as the original. To repair the broken spine of a book, you need a book binder, or else just protect and conserve to prevent further damage. Try enclosing broken items in a Melinex sleeve or tying with soft linen tape.
Maps: A brittle map is
damaged when you open it, which is why relaxing it first in higher
humidity is
a good idea. Tears get bigger when it is used, this needs professional
conservation using archival grade materials. Rolled maps need
protection with a
central roll of Jiffy foam or acid free tissue, and foam, tissue paper
or
cotton around the roll on the outside.
Cataloguing: To avoid going through
your documents all the time, catalogue them. Put a location number as
well as a
document number on the record, since hunting through archives damages
them.
Card indexes are perfectly good. Store things logically. For
cataloguing, use
simple names and classify under: Personal, Domestic/Household,
Industrial
(includes shops etc) or Agriculture.
Marking: It is no good just marking packaging as it may get lost. Mark documents on the back with a soft B pencil. On pottery use a push-nib pen, nail varnish first, then write number, then varnish on top. Tie on a shop label to objects or to tapes enclosing objects e.g. map rolls. For records and packaging use a light-fast, archival quality pen, or pencil, but not biro.
STORAGE
Furniture: Use formica
or metal
shelves and low-acid archive boxes. Avoid chipboard and MDF
due to acidic
vapours. Hang big things from the ceiling or walls, using soft linen
tapes so
you don't mark the objects.
Boxes: Ordinary cardboard is
very acidic – don't use supermarket boxes. Use acid-free
archival boxes -
shallow boxes are the most useful, not too big. For odd shapes, make grey
card containers or boxes cut to the size needed. Big things
need acid free
folders too. Correx (used on estate agents' boards)
is good to make flat
supports or boxes and reasonably inert. Valuable volumes can go in
strong card
slip cases cut to shape.
Plastic
bags:
only use polythene and cut a hole on each of the
lower corners or punch
holes to let the object breathe. Mark outside of bag – look
for pens which write
on plastic, the nib comes in various thicknesses.Don't use ordinary envelopes – brown ones are
acidic, and white are no better. For tubes use jiffy foam rolled up as
it is
made of polythene.
Photographs: Photo albums –
many are
no good as the plastic is pvc. The sticky page ones in particular
deteriorate
as the adhesive is poor quality.Loose
leaf albums with archival acid-free sheets cost are expensive. Each
photo
should go in its own Melinex envelope which contain
no harmful
chlorides, like pvc does. All these are transparent which aids viewing
of the
photographs.
Slides
and negatives should be kept in archival quality slide packets which
you can
see through. They have hanging rails for a filing cabinet.
Packaging: wrap larger objects in acid-free tissue which costs a few pounds per ream. For small objects, use plastazote foam and cut out shapes for the objects to buffer them, then sandwich it and put in polythene box. Use linen tape to tie. Don't use ordinary paperclips, they rust and mark paper. Never use rubber foam as it deteriorates badly.Cheap office products can be a false economy.
Notes copyright:
Lynn Morrison, Conservator, Saffron WaldenMuseum