Buffered Tissue

March 19, 2009

Q: Should I use buffered tissue?

A:  Considerable dialog has gone on within the
museum community about the use of buffered tissues versus non-buffered
tissues.  The pH of all papers drops over time as they deteriorate, even
acid-free papers.  “Acid-free” simply means that when it was
manufactured, the paper had a neutral pH.  Buffered tissues contain a
compound (usually calcium carbonate) meant to neutralize acids that form
in paper during natural aging.  Buffering makes the tissue last longer.
It does not stabilize nearby acidic materials.  This is partly due to
the fact that the amount of “alkaline reserve” is rather small (2-3%)
and does not migrate.  The products of acid degradation do migrate
however, so the tissue does act as a barrier to protect nearby surfaces
from that acid migration.  Theoretically, buffered tissues should not be
used with artifacts made of proteins (animal parts like feathers and
fur, or things made from animals like silk and wool) because those
artifacts prefer a slightly acidic environment.  Alkalinity also is
known to affect some pigments and dyes, and therefore buffered paper is
not recommended with color photographs or pigmented surfaces.
Practically speaking, however, unless the tissue is wet and touching the
surface of the object for an extended time, it is questionable if those
effects are taking place.  Furthermore, tissue is quite thin and the
amount of buffering rather small.  At the Alaska State Museum, we don’t
use buffered tissue at all.  We find it is difficult to keep it separate
from the non-buffered, as they look almost identical.  Buffered tissue
does cost a little more, too.  Simple acid-free tissue paper is so
beneficial for padding, interleaving, and protecting surfaces that we
don’t worry much about the small added risks or benefits that may be
associated with buffered tissues.  Not long ago, we had a conversation
with Dr. Naoko Sonoda of the National Museum of Ethnology in Osaka,
Japan.  She was showing us her collections storage, where acid-free
tissue wrapped or padded nearly everything.  We told her about various
modern products we use in the U.S., and she told me that while they are
very interested in those products, deep down they feel very comforted by
the presence of tissue because they have been using it to preserve their
heritage for centuries.  A product tried and true over hundreds of
years.  It is hard to argue with that.

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Fire Suppression Systems

March 19, 2009

Conservation Report, Ellen Carrlee for the Alaska State Museum
May 2008

SUMMARY RECOMMENDATIONS:
Due to the challenges we have with various systems in this building (computers, pipes, power outages etc.,) the asbestos issue, the degree to which we strive to be prepared for water emergencies, and the limits of technical assistance in Juneau, a wet pipe system is recommended for the ASM collections storage.  Luckily, it is one of the least expensive fire suppression systems on the market, so it would be wise to pursue the best quality product and installation we can.  We may want to consider the possibility of a VESDA system for smoke detection.  Comparisons of various systems listed below:

GAS
*       FM-200 (heptaflouropropane, a halogenated alkane) is a popular replacement for Halogen.
*       FM-200 emits hydrofluoric acid at very high temperatures, but at that point the collection is burned anyway
*       Gas will be propelled with great force giving us the same problems with the asbestos contamination (and object damage from the blast) that we worry about now.
*       In November 2006, a fire suppression system with a nitrogen propellant went off in the Museum of Ethnology in Vienna.  Large numbers of objects were thrown from shelves and damaged, and dust was even blown into closed cabinets.  Since nitrogen is odorless, a marker gas was had been added and it left a tacky film on everything.
*       Rooms must be very well sealed for gas to work well.
*       Pipe modifications must be considered in case different gas has a different flow factor.
*       Health hazard for people exposed to gas.
*       Many jurisdictions require sprinkler systems in addition to chemical suppression systems
*       Re-charge period is a time of vulnerability

WET PIPE
*       This is the most common fire suppression system, with good track record and fast response.
*       Simplicity and reliability, the fewest number of components to go wrong.
*       Low installation and maintenance expense, ease of modification with renovations.
*       Winterthur Conservation department went with a wet pipe system due to cost and its proven effectiveness.
*       UAF Museum of the North has wet pipe with VESDA in collections storage for higher levels of smoke detection. 
*       Regular maintenance includes discharge to the outside through an external valve.  At this time, valves, pumps and gauges can be verified.  This ought to happen monthly.
*       System should have flow monitors and pressure gauges to monitor pressure on both sides of the valve when closed.
*       Must be shut off manually
*       Top causes of failure are freezing temperatures or knocking off a sprinkler head.
*       Typical sprinkler head releases 25 gallons per minute (GPM).  A fire hose releases 150-250 gallons per minute.
*       Depending on the source cited, 60-80% of fires are put out with 1-2 sprinkler heads.
*       Failure rate of 1 head per 16 million installed annually.
*       Short down time after a fire…replace the sprinkler heads and turn the water back on.
*       Heads may have a fusible element that melts or a “frangible glass bulb” with liquid inside.  The bulb is color coded and ruptures at a certain temperature.

DRY PIPE
*       A dry pipe sprinkler system is one in which pipes are filled with pressurized air or nitrogen, rather than water. This air holds a remote valve, known as a dry pipe valve, in a closed position. When fire causes the seal in the sprinkler head to melt, the gas pressure is released and the flapper valve opens, allowing water through.
*       Commonly used in areas prone to pipe freezing, like warehouses, attics, outdoor loading docks etc.
*       Longer delay for response, up to 60 seconds from the time a sprinkler head opens until water comes out.
*       Failure of the compressed gas means the pipes fill with water, but as long as the seals on the sprinkler head are not melted the water will not come out.
*       Corrosion of pipe can happen, cause failure from rust on the inside
*       Must be shut off manually

PRE-CONDITONED DRY PIPE
*       Like the dry pipe, except valve is activated by electronic sensors.  There are two in each zone, and both must go off to activate the system.  If one is not functioning, neither does the sprinkler.
*       System is computer controlled
*       There is a manual release possible, but it must be located where it can be safely reached.
*       Some fire marshals may require a demo to prove it is working (ie flooding the pipes)
*       Corrosion inside pipe can make a rust-water sludge that gum up the pre-action valve.
*       Higher cost of installation and maintenance, modification is difficult.
*       Given the troubles with our building, pipes, computers and so on, a system this complicated is rife with things to go wrong.

MIST
*       Water is released at high pressure (1000 psi) pressure is made by gas or a high pressure pump.
*       Water supplied by a water supply pipe, dedicated tank or canisters.
*       Discharge triggered by electronic sensors.
*       Technology is not as old as other techniques, only available in the US for about a decade.  Research began in 60’s but has been spurred on only recently as Halon is out and there are new regulations for fire suppression on board ships.
*       Common in the cruise ship industry?  The National Parks Service and the Shelburne Museum in Vermont have been investigating its use.
*       Only a few gallons of water required to put out a fire.  Much less water damage.
*       3-D array of pipes is needed throughout the room with a nozzle every few feet.  Piping is ½” diameter stainless steel pre fabricated and then assembled on site with simple compression fittings.
*       Efficient, very little water needed, so less damage from water.
*       Small particles are thought to bind up smoke particles and result in less soot damage
*       Time of vulnerability if canisters need to be replaced.
*       Pumps require backup power supply.
*       Effectiveness to date is based on experimental and computer monitoring, so there is no track record to go on.  How it works is very elegant and appealing, but largely theoretical.
*       One aspect is that the tiny droplets give an increased surface area, helping to reduce temperature and oxygen faster in the space.  Droplets turn to steam and bind up available oxygen, acting rather like a gas to smother the fire.  This only works well in a large fire.
*       Possible problem of obstacles and structures…if the mist cannot get to the flame in a smaller fire it takes longer to put it out?

DELGUE SYSTEMS
These are wet or dry pipe systems that include open heads that just let the water flow, instead of heads that release as needed.  Also called “automatic” heads.  Not recommended for museums, but this is the kind of system we see in the movies.
Recommended for high-hazard areas like power plants, chemical storage and aircraft hangars.


Humidification Systems Summary

March 19, 2009

Ellen Carrlee, internal notes, Alaska State Museum Feb 22, 2007

ISOTHERMAL HUMIDIFICATION
Uses external heat source to boil water into vapor as steam.  Often used
in buildings that already have a boiler.  Direct steam injection comes
right from a steam source.  Steam-to-steam involves a heat exchanger to
purify steam from a boiler or other source that uses untreated water or
water with chemicals in it.  Steam can also be made in gas-fired or
electric humidifiers.  Electrode humidifiers rely on conductivity to
make steam.  Ionic bed humidifiers use cartridges immersed in water for
resistance heating to create steam.

PROS
* Little or no change in air temperature
* Allows very large air capacity in a small air stream (shorter air
handling systems)
* Available in many forms using many heat sources
* Sterile because of the high heat needed to make the steam
* Ionic bed humidifiers don’t utilize conductivity, so various water
qualities can be used.
* Steam droplets are the smallest water droplet size, and are thus
absorbed into the air quicker than the mist made in adiabatic systems.
* Electronic steam and ionic bed methods can be programmed not to
promote bacteria
* Electronic steam and ionic bed methods require fairly simple
maintenance less frequently than all other methods but direct steam
injection.

CONS
* Easy to over-saturate the air, leading to condensation in duct work
* Placement is critical…must not locate upstream of condensing
surfaces (cooling coil, duct vanes etc)
* Operating costs vary widely with fuel cost
* Cannot use the central steam that comes directly from your boiler
since it is usually full of harsh chemicals that are used to prevent
corrosion in the boiler.  Must process the water first to make “clean
steam” in a steam-to-steam process.
* Except with direct steam injection, the need to produce the steam
results in slower response time to fluctuations.  Direct steam is the
fastest response.
* Electrode humidifiers cannot use purified water because it is not
conductive enough, but hard water requires more frequent maintenance and
soft water means a shorter electrode life.
* Ionic bed humidifiers must have cartridges replaced as impurities from
water accumulate.  (can be less frequent if better water is used.)

OTHER FACTORS
* Have to have clear distance downstream to avoid condensation
* Multiple units allows staging, zoning, and reduced energy use
* Experts say a common problem is choosing an oversized unit…when in
doubt, better to use next-smaller unit, not next-larger.

ADIABATIC HUMIDIFICATION
Uses heat from the surrounding air to evaporate water into vapor.
Evaporative pan humidification from blowing air across water to pull it
into the air.  Some use a large wetted pad, known as pad-type.
Air-blast or atomizing systems use compressed air to blow water from
tiny spigots, mixing the air and the water vapor.  Ultrasonic
humidification uses high frequency sound waves to break tiny droplets
off a pan of water.

PROS
* Low maintenance compared with steam-to-steam systems
* Low operating costs when working properly
* Pad-types cannot over saturate the air

CONS
* Cools the air while it humidifies it, requiring more heating of the
air
* If enough heat is not available fast enough, the water remains liquid
and can lead to bacteria, algae, and corrosion issues
* Pad-types: Large capacity requires very wide equipment and large
supply air flow
* Atomization types easily over-saturate the air
* Long lengths of duct work for adequate mixing because the air is
cooled and cooler air won’t hold as much humidity.  Ultrasonic may need
10 feet, compressed air may need 12 feet, evaporative systems may need 4
feet.  If duct is too short, moisture hits far wall and condenses,
throwing off the RH and leading to mold and bacteria growth.
* Evaporative pan systems require frequent cleaning of the pan and risk
breeding and distributing bacteria.
* Adiabatic systems can be difficult in a retrofit because they require
a longer evaporation distance than steam humidifiers.  When mounted in
the air handler, a fog chamber needs to be put before the cooling coil,
which lengthens the footprint of the air handler.
* In ducts, airflow velocities are often wrong and allow water particles
to be carried downstream, requiring a duct expansion, mist eliminator
and drain pan.
* If tap water is used, nozzles can clog and mineral dust can be carried
with the vapor and settle out on surfaces in the building.  Use of
purified water helps, but can increase costs.
* Common mistake: not heating the air before adding moisture.  If you
add moisture to cold air, the moisture just falls out.

OTHER FACTORS
* If you place upstream of cooling coils, you reduce cooling load in
shoulder seasons
* If you place downstream of cooling coils, the warm air allows higher
capacity in the same air and reduces potential for condensation.


Integrated Pest Management Made Easy

March 19, 2009

http://www.museums.state.ak.us/documents/bulletin_docs/bulletin_29.pdf

Bulletin No 29, Winter 2007

Your building has pests.  Yes, it really does.  Ours does, too.  But are they a threat to your collection?  With an Integrated Pest Management (IPM) system, you can be active in your prevention of infestation and effective in your response if one occurs.  In the past, museums would respond to evidence of an infestation with poisons.  Many of those substances are now illegal, some contaminated or damaged the artifacts, and most were dangerous to museum staff as well.  Museums took a cue from the agriculture industry, which needed to control bugs on stored grains without contaminating the food with toxins.  An IPM system uses good housekeeping to keep pests out, traps to monitor the presence of bugs, and low temperature to treat infestations.

1. Good housekeeping aims to keep the pests out in the first place.  If you can avoid carrying in new pests, prevent them from entering the building from outdoors, and reduce things that attract them, you’re preventing the problem in the first place.  Here are some of our policies at the Alaska State Museum:
*       Eating is only allowed in the kitchen and conference room.
*       Eating during receptions is kept in a limited area.  The carpet is vacuumed immediately afterwards and trash is disposed of outside the building right after the event.
*       Beverages are not permitted at staff desks with the exception of water, coffee or tea in a closed container.
*       Collections spaces are kept free of non-collections materials and clutter is not allowed.  The cleaner your space, the quicker you will notice something is not right.
*       Packing materials are disposed of in the dumpster outside the building.
*       No plants or flowers are allowed in the building.  None.  They are a proven source of bugs as well as food for the bugs.
*       Structural gaps in the building are closed with silicone caulk, weather stripping or door sweeps.  For rodents, brassy steel wool can plug holes (and doesn’t rust.)  Mice can get through spaces the size of a quarter.
*       ¼” steel hardware cloth is used to cover floor drains.  Rats swim!
*       Keeping water drains on the roof clear eliminates many gnats. Usually a hose works fine.

2. Monitoring your populations with sticky traps gives you an early warning of trouble afoot.  We order our traps through Insects Limited: (317) 896-9300 www.insectslimited.com  The cost is approximately $50 for a box of 100 traps that can be torn into thirds.  That makes 300 traps at about 17 cents each.  For our three floors and approximately 24,000 square feet, we set about 50 traps.  They are also called “blunder” traps, so place them where a bug is likely to stroll in.  This includes along the wall, near sources of water like drains, and next to doorways.  Number each location on a map, and label each trap with its number, location and date.  Change the traps every three months, and keep a chart that describes what you found in each trap.  This task usually takes about 3 hours at the ASM.  If you take a flashlight, checking those dark corners for rodent droppings or other debris is also useful.  Our traps at the Alaska State Museum usually contain lots of spiders and sowbugs (also called pillbugs) as well as ants, large black click beetles, and centipedes.  Google images is helpful, and so are www.bugguide.net and www.museumpests.net.  When we find an insect that looks like a “heritage eater,” but we aren’t sure, we put out extra traps in that location for next time and send the trap to the Forest Service for positive identification.  We also ask staff to catch any bugs they see on a piece of scotch tape.  Anything that was originally a plant or animal has potential for insect infestation.  At the top of the list for tasty bug treats are fur, feathers, leather, and wool.

3. Treatment involves a freezer.  Research indicates that our “heritage eaters” can be killed in all phases of their life cycle by one week below -20°C.  However, many museums only have access to a frost-free freezer, with temperatures that cycle well above -20°C.  Many insects are “frost tolerant” and can make a substance like antifreeze to survive a dose of cold.  But our brains are bigger!  The artifact can be placed in the freezer for a week, then removed and allowed to reach room temperature for 24 hours, and put back in the freezer for another week to deliver a deadly second round of cold.  It is very important to package the artifact properly for low temperature treatment.  You must wrap the artifact in a soft absorbent material such as plain tissue paper, white paper towels, or a soft cloth.  This helps protect it against both the increase in relative humidity at lowered temperature and the slight increase in brittleness when things are cold.  Then, the artifact needs to be placed in a plastic bag that is well sealed.  Squeeze as much air from the bag as you can and seal the Ziplock or use a heat sealer if possible.  Lucky for us, most museum artifacts don’t have enough water in them to create ice.  However, upon removal from the freezer, condensation will form, and it is much better for that moisture to form on the plastic bag than on your artifact!  After a day of adjusting to room temperature, you can safely remove your artifact from the package.  Removing all the old bug debris is a good idea, so any future bug debris will be a clue to a new infestation.  Brushing the debris into the nozzle of a vacuum cleaner with a soft paintbrush usually does the trick.

When infestations occur, not only do the artifacts go into the freezer, but the infested space must be vacuumed, carpet steam-cleaned, and the perimeter of the area dusted with boric acid.  Occasionally, it is necessary to turn to bait.  Ant traps and D-Con are examples of bait, which are not pesticides but kill the pest through mechanisms like thinning the blood to induce internal bleeding.  Bait typically kills much more efficiently than traps.  A recent infestation of picnic ants at the Alaska State Museum was controlled with ant bait that was carried back to the nest.

Many museums do preventive treatment of incoming artifacts with the freezer.  A donation of a fur parka, for example, would definitely go in our freezer before it went into our clean collections room.  What if you don’t have a freezer, or the incoming artifact is too big?  Careful visual inspection in dark crevices can help set your mind at ease.  Look for holes, loose hair, bald patches, live bugs, bug parts, cocoons, webbing, bug nests, and tiny bug droppings known as “frass.”  Frass is round, so suspicious looking dirt can be sprinkled on a piece of paper and the paper tilted…if it rolls easily, it might be frass.  If you don’t see this evidence, the next step is to lay the artifact on a pristine white surface and place some sticky traps around it.  Wait two months or so to allow any eggs to hatch and get active.  If you see no debris on the white surface and nobody in the sticky traps, you’re probably safe.  Preventive treatment is also done with items for sale in the Alaska State Museum gift shop.

An Integrated Pest Management system is part of professional museum practice, just like monitoring your temperature and relative humidity, and keeping your light levels appropriate.  Dealing with an infestation after it happens is upsetting, time consuming, difficult, and often means irreversible damage to museum collections.  An ounce of prevention is truly worth a pound of cure.  Have questions?  Call us!  Scott Carrlee 465-4806 or Ellen Carrlee 465-2396.

Heritage-eating bugs

Common Heritage Eaters
1:00 Cigarette beetle
2:00 Drugstore beetle
3:00 Confused flour beetle
4:00 Saw-toothed grain beetle
5:00 Carpet beetle (black, white, and orange)
6:00 Common carpet beetle larvae
7:00 Varied carpet beetle  (black, white and gray)
8:00 Common dermestid beetle
9:00 Larder beetle
10:00 Webbing clothes moth (ragged wings)
11:00American spider beetle
12:00 Hide beetle (has white tummy)

insect debris

Insect debris from L to R: light brown frass and wood bits from a powder post beetle infestation, #2 pencil, larva and striped shed larval casings, soft white cocoons from the casemaking clothes moth.
Harmless bugs

 
A dime gives scale to these “harmless” bugs as well as the generally smaller-sized “heritage eaters.”

1:00 and 2:00 spiders are very common and may make webs and nests but eat other insects, not collections.  A spider population out of control can be reduced by setting out a large number of sticky traps.
3:00 Minute scavenger beetles eat mostly molds and fungi.  These were living in damp plastic bags used to stuff out a mukluk.
4:00 Common weevil, a grain eater.
5:00 Carpenter ants do not eat artifacts, but if you see one, your building itself could be in trouble.
6:00 Common housefly, mostly a nuisance for leaving droppings called “flyspecks” on artifacts.
7:00 Picnic ants are looking for sugar.  This one was attracted to a puddle of punch spilled under a printer during a reception.
8:00 and 9:00 Sowbugs or pillbugs come in many shapes and are found in damp areas.
10:00, 11:00 and 12:00 Carabids, click beetles and other large beetles are generally harmless and die soon after coming indoors


Dust in Museum Exhibits

March 19, 2009

Bulletin 30, winter 2008  No pdf link on website yet.

We have long known that dust causes damage to artifacts. The basic
information we tell museums about dust includes:

1.      Dust is unsightly and makes your collection look poorly
maintained.
2.      Dust is abrasive on a microscopic scale due to tiny sharp
mineral particles, such as quartz.
3.      Dust contains pollens, skin cells, insect bits, and other
organic matter that feeds biological growth.
4.       Dust can be acidic.
5.       Dust is “hygroscopic,” meaning it attracts water and holds it
against the surface of an object, contributing to staining, corrosion,
and biological growth.

Recent articles have given us a new understanding of the impact of dust
on our collections.  A paper presented at the 2004 conference of the
American Institute for Conservation  described the forces that help dust
stick to surfaces.  One of these forces comes from sticky “exopolymers”
made as a waste product of microbes (mainly bacteria).  Accumulating
dust provides more food for these colonies of microbes, and layer upon
layer of “biofilm” forms, with the bottom layers becoming firmly adhered
to the surface of your artifact.  Spikes in humidity can encourage the
initial growth and speed the growth of biofilms.  Periods of low
humidity after high ones can stress the bacteria, and might cause them
to produce even more sticky exopolymers.  Yet another reason to try to
keep our museum humidity levels stable!

Other recent articles have explored the role of visitors in creating
coarse dust.  Considerable amounts of dust enter the museum on visitors’
clothes and shoes. Visitors are such a direct contributor to dust that
one study showed dust amounts are cut in half for every 3 to 4 feet of
distance between a visitor and an object. Fibrous dust, largely from
clothing, accounts for only about 3% of the dust in exhibits. But since
the particle size is large and visible, fibrous dust contributes
significantly to the appearance of dustiness. This dust tends to be
thickest at eye level. Dust entering on shoes is more concentrated
closer to the entry, and in greater quantity under wet weather
conditions than dry conditions. This kind of dust only rises about 4 or
5 inches off the floor.

Some preventive measures can be taken. Placing objects in cases and
further away from visitor traffic is one solution, of course, but is not
always possible or desirable. Tightly sealed exhibit cases are better
than ones with gaps, but require construction materials that do not
off-gas harmful chemicals like formaldehyde and acid.  Placement of mats
in entryways significantly reduces the amount of dirt brought into the
building on shoes. Vigorous air movement also increases the rate of dust
coverage. Live performances and pathways through exhibits that involve
sharp turns are examples of “dust raising” activities. Air movement from
fans and open windows encourages dust circulation as well. Sometimes
those factors are unavoidable, but strategic decisions can be made,
particularly in relation to artifacts on open display.

Cleaning of collections on exhibit should be scheduled at least once a
year. Objects displayed in the open should be dusted annually. Artifacts
in exhibit cases can be cleaned on a rotating schedule, with a few
exhibit cases cleaned one year and others the next. After a few years,
all cases will be done and the rotation can begin again. It is useful to
have a map of exhibit galleries that can be annotated with notes and
condition reports if needed.

Good housekeeping is divided into two levels of cleaning. Regular
less-skilled cleaning can be done by janitorial staff or untrained
volunteers, including daily vacuuming and regular dusting of furniture.
Specialized cleaning of exhibits requires more skill. HEPA-filtered
vacuums are especially helpful, since they release less dust back into
the air than traditional vacuum cleaners. Closer to collections objects,
vacuums with adjustable suction (such as a Nilfisk vacuum with a
rheostat) are preferable. Dusting techniques that involve rubbing are
abrasive to most surfaces on a microscopic level, and are best avoided
if possible. Most items can be effectively cleaned with a soft
paintbrush, gently fluffing the dust from the surface into the nozzle of
a vacuum cleaner. For fragile surfaces, you may cover the nozzle with
fine nylon netting, such as tulle, secured with a rubber band.  Many a
loose bead or detached fragment has been saved this way, and you will
see sooner if the suction is too strong (hairs pulled from a taxidermy
specimen, for example).  Feather dusters can be helpful, but beware of
any rough quills that could scratch surfaces and be sure to vacuum the
feathers frequently to remove dust.

Glass and plexiglass surfaces are often the first to show dust. The
Sheldon Jackson Museum in Sitka, which has some of the cleanest exhibit
galleries in the state, has found that cleaning glass with paper towels
and a mixture of 1 part white vinegar to 4 parts water is as effective
as any cleaner. Any cleaner should first by applied to a cloth, and then
to the glass or plexi. Fine mist spray can penetrate cracks of exhibit
cases and damage artifacts. Always be careful to let the case air out
before closing because of the acetic acid or ammonia vapors released by
some cleaners.

Plexiglas(r) requires special attention to prevent the plastic from
fogging or scratching. The Alaska State Museum uses specially formulated
commercial Plexiglas(r) cleaners. One product is called Norvus, and is
available on the Internet through vendors such as Amazon.com and Tap
Plastics.  Novus 1 is for cleaning, Novus 2 is for removing fine
scratches, and Novus 3 removes heavy scratches. Apply with a clean
cotton rag.

Good housekeeping is an important part of preventive conservation.
Cleaning also gives you an opportunity to inspect your exhibits for
problems such as bugs or shifted objects. While updating exhibits is
often not in the budget, dusting costs little and freshens up
appearances.

(sidebar)

Five Defenses Against Dusty Exhibits
1. Sealed exhibit cases are the gold standard.
2. Establish regular dusting schedules.
3. Use extra floor mats near doors.
4. Avoid the use of fans and open doors or windows unless absolutely
necessary.
5. Avoid drastic swings in humidity levels.
6.  Shut down the HVAC when cleaning dust out of the vents.

References:

Tarnowski, Amber L., Christopher J. McNamara, Kristen A. Bearce, and
Ralph Mitchell.  “Sticky Microbes and Dust on Objects in Historic
Houses.”  AIC Objects Specialty Group Postprints, Vol. 11, 2004.
 Yoon, Young Hun and Peter Brimblecomb.  “Dust at Febrigg Hall.” The
National Trust View, Issue 32, Summer 2000.


New Frontiers for the Conservation Lab

March 19, 2009

http://www.museums.state.ak.us/documents/bulletin_docs/bulletin_26.pdf

Bulletin 26 Spring 2007

Published as “Conservator’s Corner”

by Ellen Carrlee

 

Along with other renovations in the Alaska State Museum basement, the
conservation lab has had a makeover, with new flooring, new paint, and
new lab tables.  The spruced-up space will be used for treatments, the
conservation library, the conservator’s office area, textile
conservation supplies, study samples (fragments of ivory, skin, basketry
and other materials for developing treatments) and the binocular
microscope.  The new tables for treatments have chemical-resistant black
resin tops and are the kind typically used in college chemistry
classrooms.  The narrow former darkroom that served as the only
conservation lab space for many years can now be used more effectively
as the conservation chemical laboratory, with its deep sinks, fume hood,
and safety features such as a flammables storage cabinet and emergency
eyewash station.  Most conservation treatment supplies are stored there,
and certain wet treatments will still occur in that space.  First on the
docket will be a basketry conservation project to finish the treatment
of several waterlogged archaeological baskets from southeast Alaska.
Among the most important are two very old baskets that have already
received impregnation with polyethylene glycol (PEG) wax to replace the
excess water.  Water has such strong surface tension that simple
evaporation from old waterlogged wood and basketry materials causes
warping and severe damage.  While the PEG treatment was successful in
halting deterioration, these ancient baskets are still too fragile to be
exhibited.  A consolidation is needed, and research is underway to
determine the best approach.  Two graduate students in conservation will
be coming to assist in this project as well as treat other baskets in
the ASM and SJM collections.  Molly Gleeson will be coming from the
UCLA/Getty Museum art conservation program, and Samantha Springer will
be coming from the Winterthur/University of Delaware art conservation
program.  They will arrive in mid-June, spending several weeks in Juneau
working on the collection and learning about gathering and processing
spruce root and an introduction to weaving from Tlingit/Haida weaver
Janice Criswell.  Then they will travel to Sitka to work on the Sheldon
Jackson Museum collection and learn more about weaving from Tlingit
weaver Teri Rofkar until mid-August.  The interns will also share their
knowledge and treatment techniques with the weavers in what promises to
be an exciting and rewarding collaboration.  Successful treatments will
mean many important historical and archaeological baskets currently too
fragile to be exhibited will be able to be studied, appreciated, and
enjoyed by the public.

 

Conservation Lab BEFORE

Conservation Lab BEFORE

 

Conservation Lab AFTER

Conservation Lab AFTER


2007 Basketry Internship

March 19, 2009

http://www.museums.state.ak.us/documents/bulletin_docs/bulletin_27.pdf

Bulletin Vol 27 Fall 2007

The Alaska State Museum conservation lab hosted two interns for a basketry conservation project this summer.  Both interns were graduate conservation students finishing their second year of studies: Molly Gleeson from the UCLA/Getty Museum program, and Samantha (Sam) Springer from the University of Delaware/Winterthur Museum program.  These programs and the interns themselves provided the funding to come to Alaska.  The ASM provided the supplies and supervision.  In the first week, Molly and Sam brainstormed treatment solutions for the archaeological basketry fragments in the lab, and did a preliminary cleaning on a group of flattened spruce root work baskets that may become a study collection.  In the second week, curator Steve Henrikson assigned each intern two horrifically damaged baskets.  Molly worked on two Haida baskets collected by Lt. George Thornton Emmons in the late 1800’s.  The baskets had severe deformation, losses, tears, and old repairs of painted tape.  Sam’s Tlingit basketry projects also had intense tears, losses and deformation as well as old insect infestation and surface soiling.  The two Tlingit baskets still retain the inverted Y-shaped folds on the sides that indicate the baskets were folded for storage and thus not made for the tourist market.  Treatments included overall re-shaping in a humidity chamber, localized humidification with Gore-tex and blotter paper to align tears for repair with tiny splints of Japanese tissue and wheat starch paste, and innovative loss compensation with cotton gauze and sculpted paper pulp bulked with adhesive.  The interns were also able to examine baskets in the collection with Steve Henrikson and Tlingit-Haida weaver Janice Criswell.  Janice and weaver Mary Lou King twice took the interns “rooting.” They dug spruce roots, processed them, and each wove a basket under the tutelage of Janice and Mary Lou.  Together the interns formed quite a dynamic duo, becoming fast friends and helping Ellen make improvements to the lab.  Molly’s boyfriend Germán visited from Chile and proposed marriage on a beautiful Eaglecrest hike.  Germán and Samantha’s husband Seth also became friends, hiking and seeking satellite TV soccer matches while their partners immersed themselves in basketry.  Samantha’s professor Bruno Pouliot from Delaware also visited the interns for several days, and accompanied them to Sitka to kick off the second part of their internship.  Their first day on the job, they appeared on the radio to promote that evening’s free public program at the Sheldon Jackson Museum, a Conservation Clinic to provide advice to locals about their artifacts.  The clinic included ASM Curator of Museum Services Scott Carrlee (also a conservator.)  More than fifty people came, most bringing artifacts for examination, making the event one of the most successful public programs at the SJM in recent years.  In addition to several basketry treatments, the interns were able to meet with retired curator Peter Corey, National Parks Service curator Sue Thorsen, and Tlingit weaver Teri Rofkar to study baskets.  They also gathered materials and wove baskets with Teri.  In an exciting development, the interns are working with Teri and Janice to co-author a paper for an important international museum conference.  The International Council for Museums Conservation Committee (ICOM-CC) holds a major conference every three years.  In 2008, the conference will take place in New Delhi, India with the theme “Diversity in Heritage Conservation: Tradition, Innovation and Participation.”  The basketry abstract was provisionally accepted in July.  Only 40% of the proposed abstracts were accepted, and final paper is due in November for final review.  If accepted, this will be one of the very few professional conservation papers that will include a first-person Native voice, instead of the Native perspective only interpreted through a conservator.  Internships such as this one provide up-and-coming conservation professionals an opportunity to work with Native artists and museum professionals in the environment where the artifacts were made, allowing for multiple perspectives and a deeper understanding of the conservator’s sensitive role in preservation.  These are lessons that can be carried on throughout their careers.  In return, interns take on difficult treatments and share the latest techniques and theories in conservation they have learned in school.  Today’s interns are tomorrow’s professionals, linking us to museums in the lower 48 and creating a network of colleagues.  The long-range plan for the ASM conservation program includes dividing the collection into materials groupings for systematic surveys.  Each survey will identify priorities for conservation treatment and provide ideal internships for future conservation students.  Next summer’s project targets the museum’s natural history collection.  Stay tuned…

Rim of spruce root basket 2006-18-1 BT by Samantha Springer

Rim of spruce root basket 2006-18-1 BT by Samantha Springer

 

 After treatment by Samantha Springer using Japanese tissue and paper pulp with wheat starch paste and watercolor.

After treatment by Samantha Springer using Japanese tissue and paper pulp with wheat starch paste and watercolor.

 

 

 

 

 

 

Molly Gleeson inventing a new repair technique using cotton gauze, paper pulp, Japanese tissue, wheat starch paste and PVA emulsion adhesive.

Molly Gleeson inventing a new repair technique using cotton gauze, paper pulp, Japanese tissue, wheat starch paste and PVA emulsion adhesive.

After treatment of large loss near base of Haida basket II-B-493

After treatment of large loss near base of Haida basket II-B-493

 

Janice Criswell teaches Samantha Springer to weave spruce root in Mary Lou King's kitchen.

Janice Criswell teaches Samantha Springer to weave spruce root in Mary Lou King's kitchen.