How To Identify A Powder Post Beetle Infestation - November 13, 2013

November 13, 2013

I spent an afternoon helping the Northville Farm Heritage Centre with identifying and isolating wooden artifacts infested with Powder Post Beetles.  I wrote about steps to take when dealing with an infestation and about infestation in general in the two previous posts so won't repeat that here.  This post has more pictures to help you search your own wooden artifacts.

Our objectives with the work at the farm centre was to:

• identify anything infected and remove it,
• place smaller artifacts in garbage bags to isolate them,
• place the smaller artifacts for a minimum of two weeks in a freezer,
• place larger artifacts that could safely be moved into a holding area,
• identify areas of significantly larger objects and structural infestation for future spraying.

We searched three buildings for the evidence of sawdust laying about or holes in the wooden artifacts.  Some of the holes look recent with lighter colours and sawdust others look older with darker colours and no sawdust.  These photographs show what we found for recent activity and what you can look for:

Barrel header with sawdust

Saw handle with holes and dust.

Butter churn heavily infested

With the older holes that usually have no sawdust treatment is still necessary since the larvae can survive for many years within the wood.  We bagged and froze the smaller artifacts as well and documented the larger ones for spraying in the spring.  Here is an example of what appears to be older non-active holes with no recent sawdust evident:

Brush with older holes.

Wheel, painted with older holes

We identified several areas in two of the buildings where spraying with Timbor should be done in the spring.  I wrote about spraying in a previous post and steps to be taken with infestation.  Timbor is safe to use and can be effective over a longer period of time to reduce the population of beetles.  Spraying is recommended in the spring around second or third week in June when the beetles are most active.  Fresh sawdust is the clear sign of beetle activity so cleaning up the sawdust shortly after spraying and monitoring for more will let you know if you need to re-spray. The farm centre has been doing this already for the last few years by spraying the structure of their buildings but now they can spray the larger, individual items we have seen that are infected.  Here are photographs of most of the artifacts we found with beetle infestation:

Most importantly, they must isolate all wooden artifacts as they come in. Smaller ones can be frozen for  two weeks; larger ones sprayed.  In both cases they should be isolated from the rest of their collection and only returned to the general collection when they have been treated.

One area had a large amount of sawdust on a barrel header on the main floor.  After removing it and searching for further evidence we came across a wooden butter churn that was heavily infested sitting on a shelf above.  The sawdust fell down between the shelf boards onto the barrel header below.

Conservation Tip:  It is critically important that all wooden artifacts brought in be inspected for infestation and if there is any evidence isolate them and treat them as soon as possible.  Isolation can be as simple as bagging or keeping them outside or in a building without exposed wood and cement floors.  Spraying is most effective when the beetles are active in the spring when they emerge from the wood for mating.  If you have had an infestation it is necessary to spray each spring over a period of years to reduce the population to a manageable number.  Regular inspection of your wood collection is necessary.  Remember that painting and varnish will not discourage them, they live in the wood and will bore their way to the surface.

Paper Artifacts Handling - General Information - November 2013

November 12, 2013

Paper Artifacts

As with all artifacts that come into the museum we examine each one carefully to determine the best way to proceed with cleaning, packaging, storage, and possible repair and display.  The following are some of the conditions paper artifacts are subject to which can be conserved usually under laboratory conditions:

1. stained by water, humidity or other liquids,
2. ripped, earmarked, 
3. missing pages, missing covers or in pieces, 
4. cracked or split spine, 
5. repaired with scotch tape, other tape or adhesives that is recent or has yellowed,
6. pest damage such as silverfish or book lice,
7. improperly mounted.

Each condition is carefully noted as a permanent record and appropriate action taken.  For community museums, only minimal treatment can be undertaken due to the costs involved.  That usually involves documenting, photographing, flattening minor rolls or curves, proper storing or packaging, some minor repairs with Japanese papers and paper adhesives if funding is available, and researching the history. 

For example, with earmarking such as corners folded or a part of a page folded back when stored or handled we resist the temptation to correct it by folding it back in place.  Attempting to correct it may cause further damage particularly if the paper is very fragile so is best left as is for now.  This type of condition can be corrected by engaging a paper conservator who will follow the correct procedures to do repairs such as applying humidification to a particular area or to the entire document to loosen the paper fibres, flattening the document, and drying it all under controlled conditions.  Paper artifacts that are moderately rolled or with moderately curved edges can be flattened by placing it between two larger pieces of thicker paper such as matting board and laying a large flat weight on top such as a piece of plywood of the appropriate size.  This does not always work if documents are severely distorted.  A paper conservator can help to determine if the humidification process mentioned above may be necessary.  Here is a photograph of a flattening in progress at the museum.

Large paper document being flattened.

It is possible to wash some paper under laboratory conditions to remove staining.  This is a labour intensive and often expensive process that is usually only done on very precious documents under highly controlled conditions.  Repairs can be done to replace pieces, fix cracks in spines, consolidate tears, loose pages or pieces.  Often Japanese papers of appropriate various thicknesses and colours are used for this purpose as is adhesives designed specifically for paper.  The papers are mostly used to stabilize the pages but in some cases can be colour matched to replace missing pieces.  Adhesives used in the past for attaching covers to books were sometimes a good source of food for pests; modern adhesives are designed to avoid this.  Modern adhesives are reversible, strong, and non-staining.  Examples are starch-based or methyl cellulose.  Stabilizing a loose or cracked spine on a book is a good preventive measure to avoid further tears or breaks.  A paper conservator can do this with near invisibility to the casual observer.

Precious paper artifacts should be packaged in acid free sleeves and labelled.  Another option is to use Mylar sleeves and acid free backing boards of the type that are used to store comic books.  These can often be obtained in local comic stores for a reasonable price.  Mylar is recommended due to its inert composition and acid free backing boards are important to reduce the chance of a paper artifact getting bent in storage or handling.  Mylar is also transparent which means it can be used to put a document in an exhibit and keep it protected.  Obviously this packaging is not the best option for all paper artifacts but should be done for those precious pieces.  The following photographs show two paper artifacts we recently packaged at the museum in acid free envelopes.  The accession number and archival number are both written on the outside of the envelope.  Cotton gloves are used for handling.

Cartoon booklet stored in acid free envelope.

1930 school book stored in acid free envelope.

References

CCI - Caring for paper artifacts  Canadian Conservation Institute - How to care for paper documents and newspaper clippings.
Asiarta Foundation - Works of art on paper conservation techniques - Paper conservation techniques
NEDCC - Repairing paper artifacts - NorthEast Document Conservation Center