Monday, 28 October 2013

Wooden Objects Pest Management Guidelines August, 2013

August, 2013

NOTE: These guidelines are specific to the Annapolis Valley, Nova Scotia CANADA and the result of a request from a local community museum.  Consult with a conservator in your area for treatment specific to your location.  Where chemical use is recommended follow MSDS (Material Safety Data Sheet) instructions for safe handling.
Pest infestation can be difficult to treat.  For example, Powder Post beetles can survive for years within the wood in larvae form and can only be adequately treated as they emerge from the wood.   However, Timbor is a relatively non-toxic chemical that will kill the beetles as they emerge.  It is suggested that the infested wood be sprayed regularly, perhaps yearly or if more evidence of beetle activity is observed.  The most critical step in controlling it is to carefully examine new objects as they come in and regularly inspect objects in your collection.  Wood products of all kinds are susceptible even if varnished or painted.   

The following are a general set of guidelines for dealing with this type of problem.  This information is a summary of this type of problem from available literature combined with information obtained from conservators and pest control officers I have contacted.  It is suggested that these steps should be followed in this order as objects come in. 

1) ISOLATE: all wooden objects that are brought in should be isolated from the rest of your collection until they are verified as free of infestation or have been treated.  Bag all the objects that are small enough to fit in bags.  Place larger objects in a tent or tarp big enough to sit it on and have it completely covered.  Infestation evidence will then be deposited in that space for observation.

2) EXAMINE: very carefully examine each object for these three things - holes, debris such as legs or other beetle body parts, frass (beetle excrement, a fine powder).  NOTE: this is not always followed by curators and other museum workers but is a critical step.

3) IDENTIFY: if you are NOT confidant that it is powder post beetle, bag the evidence and take it to the Agricultural Research Station in Kentville or to the Nova Scotia Museum in Halifax for identification.

4) TREAT: smaller objects with infestation can be bagged and placed in a freezer for a minimum of two weeks.  This would normally kill off most infestations and the object would then be safe to move to your collection area.  Larger objects with infestation can be sprayed with Timbor and kept in a tent with pest strips such as Home Defence Max from Canadian Tire for at least two months.  The strips are placed around the tent OR can be cut up and placed in plastic containers with holes in the sides at the bottom edges so the beetles can crawl inside.  WARNING: these strips are toxic - USE GLOVES, open and handle outside as much as possible, DO NOT ALLOW STRIPS TO TOUCH THE OBJECT.  Placing them in plastic containers is a way to reduce contact with the chemicals in the strips.  These strips can be used in cabinets as well but follow the handling rules.

5) OBSERVE: set up a schedule to examine all your wooden objects at least every 6 months for evidence of infestation and if found, treat immediately.
REFERENCES    general guidelines for museums – all pests.     a list of most common pests and how to identify them.

Powder Post Beetles - July, 2013

July, 2013

A local museum contacted me recently about Powder Post beetle infestation that they had been dealing with for a few years.  They have several older wooden buildings with lots of small and large wooden objects housed within.  They have been spraying every year with a product called Tim-Bor.  The results have been encouraging with much less infestation over time but not yet completely solved.  These beetles bore into wood and deposit eggs.  When the eggs hatch the larvae eat their way out of the wood, mate in the spring and the cycle starts again.  They had asked me about the best way to deal with new objects coming into the museum and any existing objects that may be infested.
How do you know you have a beetle infestation?  Here are a few photographs of holes in wooden objects and a photograph of the dust which is a combination of sawdust and frass (insect excrement).   

Beetle holes - mallets
Beetle holes - pulley
Beetle dust - stairwell
Beetle dust - barrel base

There are several kinds of beetles that exhibit the same characteristics that can be treated the same way.  Spraying with a boron based product such as Tim-Bor, Borasol, or Ambush every year for several years will reduce the population and keep it under control.  Watch for beetle activity evidence such as the dust as shown in the photographs every year usually in summer or late spring.  Spray all the wooden areas (walls, stairwells, doors) and the larger objects.  These products are easily handled but require basic handling equipment to apply.  Refer to the safety data sheet for any of these products first before usage.

Any wooden objects of a small size can be treated by depositing them in a freezer for a minimum of two weeks.  Such things as wooden mallets, pulleys, wooden handled tools, and the like which can fit in the freezer are good candidates.  Wooden wagon wheels, carts, poles, and the like are usually too big so should be handled differently.  Maintaining a low temperature over two weeks will kill off any of the eggs, larvae, or beetles present in the wood.  There is some variance but typically, freezers maintain a temperature of around -18C.  Since beetles are active in the spring and lie dormant over the winter they are able to handle fluctuation in temperatures but not a sustained cold temperature.  Our winters in Nova Scotia have fluctuating temperatures between freezing and thawing so our beetles have adapted to that environment.  After two weeks you can put the objects back into the collection where appropriate.

Beetle holes - wheel

For larger objects such as the wagon wheel shown in this photograph I suggest spraying them every spring around middle of June for Nova Scotia which is their optimal time for reproduction.  They tend to be active, moving toward sunlight at that time.  Around this time you should see evidence of their activity - either bore holes or dust.  Sometimes the bore holes may not be visible until the spring because the object has been sanded and painted. 

All new wooden objects coming to museums should be carefully examined for evidence of pests.  If so, they should be bagged and isolated for a period of time to determine if they are actively infested.  Bagging will allow for any evidence of activity to be observed.  If they can be stored in a non-wooden environment for a time this would be best.  If they are small they can be put straight into a freezer for two weeks.  Larger objects with bore holes should be sprayed and examined in late spring or early summer for evidence of beetle activity.

Conservation Tip

With respect to preventive care - objects in collections should be examined as a minimum at least twice per year.  Wooden, textile, paper or leather objects for pests and mold; metal objects for tarnish and rust.  Identifying problems as soon as possible can prevent more serious infestation or damage that would be more difficult to treat if left undiscovered.  Careful examination will then determine what treatment is necessary, the costs in terms of materials and time, and then a plan to implement the treatment. 

Sunday, 13 October 2013

Some New Objects Came In - June 25 2013 (Continued)

July 2, 2013

Alcohol Jug - Luther
Alcohol Jug - Proverb

Perhaps the most important part of historical objects coming in the museum from the public as donations are the stories that accompany the objects.  Last week I wrote about the objects and briefly described two of them with photos.  This week I have two more from the same group that are of particular interest.  The person who brought them in shared what information he had on his objects.  This is especially exciting and important because these stories are what helps us to date them, understand how they were used, which family members used them, and any repairs done to them.

These objects are alcohol jugs with sayings inscribed in German on the front and raised images such as flowers and birds in many locations.  In both cases the handles on the back are broken with missing pieces.  One of them has a quote from Martin Luther, the other a German Proverb.  One of them shows many cracks with obvious repairs and yellowish-brown staining.  The staining is on or near the cracks so represents an excessive amount of adhesive used to do repairs.
There are several interesting aspects to these examples:
  1. the owner said he had played with these as a child; 
  2. the quotation on the front in German; and
  3. the conservation possibilities. 
Since we know the age of the donor (in his 90's) we can date the jug to at least his childhood.  The origin is unknown.  I am continuing research on determining the maker and date of these objects.  If any of you know more about these please leave a comment below.

The quotation on one jug is attributed to Martin Luther (1483 - 1546) as follows:
"He who loves not wine, women, and song remains a fool his whole life long."
On the other jug the quotation is a German proverb:
"Happy is the one who forgets that which cannot be changed." 
The possibility for conservation on the jug with the Martin Luther quotation is that the adhesive could be removed, the object disassembled, the pieces cleaned and reattached with conservation grade adhesive.  The missing handles can also be remade (molded), painted with exact colour match, and attached.  The end result would be a "like new" object.  Repairs undertaken by conservators are done ethically in such a way that the original aspects of the object are restored but that the repairs will be obvious under intensive observation such as a magnifying glass or a microscope.  It is also critically important that any repairs be easily reversed.  The entire repair process would be documented in detail with photographs at every stage and becomes part of the historical record of the object.  This is a labour intensive process and would usually only be attempted on objects of special historical significance due to the cost involved.  In our case I would recommend that it be left as is since the repairs represent an important aspect of the history of the object.

Information Tip:

More information is available on by searching on accession number 2013.014.001 or 2013.014.002.  Just type in or cut and paste the accession number in the search box on the upper right of the page and press enter to bring up more information.  There is a detailed description plus measurements, condition information, some history on the original owner, and conservation work.

Tuesday, 1 October 2013

Some New Objects Came In - June 25 2013

June 25, 2013

Someone came in this week with some historical objects from home to donate to the museum.  This is a regular occurrence as people clear out the attic or decide that it is time to make some of their family artifacts available for others to enjoy.  This is one of the joys of working in a never really know what may come walking in the door.  There are often pleasant surprises that can be of great interest to the public.  Here is what was brought in:

  • a child's chair from the Victorian era (1837 to 1901) - possibly late 1800's,
  • a bone handled straight razor in its box without a top,
  • a fully functional mechanical pencil with lead refill - possibly early 1900's,
  • a 1961 book of cartoons from the Halifax daily newspaper of the time in mint condition,
  • a school reader from the 1930's with student notes, underlining, and other scribbles,
  • a military canteen from the 1950s in its carrying case,
  • a brass book mark with a colourful butterfly at one end,
  • a silver plated 1880's spoon warmer,
  • two tall, ceramic alcohol jugs with different sayings in German.
Tasked with doing conservation work on these objects I can say that very, very little needs to be done.  I generally concentrate on cleaning, polishing, very minor repairs, packaging, storage, photographing and database updates (  In all cases these were clean meaning that I did not have to brush off any dirt or wipe off dust.  They are all showing some of what could be called normal wear and tear which is part of the objects' history and thus would need no remediation.

Victorian Era child's chair.
An example is the child's chair which is very solid and sturdy but shows some rips, minor staining, and loose threads in the seat cover.  It has been refinished with a varnish and the seat cover may have been replaced.  With the under seat strapping and frame in very good condition I can see no reason to do any changes.  Normally, I would recommend that wood not be refinished, the natural patina is often best left as is.  Antique TV shows often point out that wooden objects loose value when refinished.  The natural wear and patina reflect the use of the object and from conservator's point of view is a valuable reflection of the history of the object.  This chair shows the craftsmanship of the era and is a testament to the maker's skills and pride in producing high quality goods.

Late 1800's spoon warmer.
Another example is silver plated spoon warmer which is showing the usual black spotting and scratches from polishing or wear.  Since it is silver plated there is very little reason to try polishing it further since there is little or no silver left in these areas.  This object was used to keep spoons warm when boiling water was poured inside and a small lid was closed to keep the spoons warm.  This practice was popular in some circles in the 1800's but died out at the turn of the last century.