Megan,

For historic objects, the "dryness" of wood depends only upon the RH of its ambient environment.  If the RH is low, the wood will give up moisture, and if the RH is high, it will gain moisture to be in equilibrium with its environment.  This goes on constantly as the environment changes.  However, wood never completely loses all of its moisture in any usual indoor environment.  

A finish on a wooden object does not add (or subtract) moisture.  At best, a finish can somewhat slow down moisture moving into or out of a piece of wood (if the finish is a good vapor barrier and the coating is relatively thick), or it can have no significant effect if it is a poor vapor barrier.

What you are probably noticing is an optical effect on the surface of the wood.  A primary purpose of a finish on wood is to visually saturate the surface of the wood, eliminating the scattering of light, and therefore making the surface appear richer and darker.  As an unfinished object ages, its surface often collects dust/dirt that becomes ingrained in the wood cells, dulling the appearance.  In addition, if the wood has been exposed to high light levels or wetting by water, the surface can become rougher, scattering more light and appearing duller or "dryer."  However, it is NOT dry.  

Your chair does not require any special preservation treatment - it just should be kept in reasonable environmental conditions.  They do not have to be perfect conditions, particularly for a chair which has inherently higher tolerances than many other types of furniture.  In fact, many so-called preservation treatments actually promote future deterioration.  So, in this case, hands off to promote preservation.  Please let me know if you have any further questions.

Marc

American Conservation Consortium, Ltd.
     4 Rockville Road
     Broad Brook, CT 06016
     www.conservator.com 
     860-386-6058 

*Collections Preservation Consultation
*Conservation Assessments & Surveys
*Environmental Monitoring & Low-Tech Control
*Moisture Management Solutions
*Collections in Historic Structures
*Collections Care Grant Preparation
*Conservation Treatment of:
     Furniture
     Painted Wood
     Horse-Drawn Vehicles
     Architectural Interiors 
     Decorative Objects & Folk Art

Marc A. Williams, President
     MS in Art Conservation, Winterthur Museum Program
     Former Chief Wooden Object Conservator, Smithsonian Institution
     Fellow, American Institute for Conservation (AIC)


----- Original Message ----- 
From: Megan Maxwell 
To: [log in to unmask] 
Sent: Thursday, May 27, 2010 12:36 PM
Subject: [MUSEUM-L] protecting unfinished wood


I'm the curator at an historic house museum in Texas.  We have an old potty chair that apparently has never had any type of finish on it.  Does anyone have a recommendation for how to protect the unfinished wood?  It is very dry, and unfortunately we do not have a proper storage place for it.  We'd like to keep it from drying out further and do as much to protect it as we can.  I would appreciate any suggestions!

Thank you

Megan Maxwell
Curator
Starr Family Home State Historic Site
Marshall, TX 

=========================================================
Important Subscriber Information:

The Museum-L FAQ file is located at http://www.finalchapter.com/museum-l-faq/ . You may obtain detailed information about the listserv commands by sending a one line e-mail message to [log in to unmask] . The body of the message should read "help" (without the quotes).

If you decide to leave Museum-L, please send a one line e-mail message to [log in to unmask] . The body of the message should read "Signoff Museum-L" (without the quotes).