Wooden barrel with iron bars

Ulla Klemela <ulla.klemela [at] nba__fi> writes

>A wooden barrel full of small iron bars was lifted from a medieval
>wreck-site in the Finnish coast of the Baltic Sea in 2006. The iron
>had corroded readily during the centuries of submersion forming a
>concretion around the whole barrel and infesting the wood badly with
>corrosion products.  Upon excavation in the lab about half of the
>largely mineralized iron bars were removed and subsequently
>stabilized. The remaining whole still consists of hundreds of iron
>bars corroded together and several wooden planks of the barrel.
>
>It is now dry and the plan is to leave it like that and display it
>partially excavated. The problem is how to stabilize and display
>such a composite artifact. ...

If the untreated iron material can be removed, remove it and store
or display separated from the treated iron and wood barrel.  If it
cannot be removed store or display the composite artifact with
respect to the active corrosion, i.e., lower the humidity to the
level required for the iron.  The lowered humidity's effect on the
wood should be minimal to no effect since the barrel making process
would have used seasoned, i.e., properly dried material.


                                  ***
                  Conservation DistList Instance 23:17
                 Distributed: Sunday, November 15, 2009
                       Message Id: cdl-23-17-005
                                  ***