Stabilizing Wet Inorganic Materials

METALS

Facts about metals

Many metals will corrode under damp conditions. Iron objects and archaeological metals are especially at risk.

What to expect when metals get wet

Corrosion can proceed very quickly in unstable objects. Corrosion such as rust can stain nearby objects.

Drying metals

• Handle with gloves.
• If water was contaminated and metals are fully wet, rinse in clear water if possible.
• Blot dry, then air dry in actively moving air (fans and dehumidifiers).
• A hair dryer, heater, or oven can be used to gently accelerate drying priority materials.
• If possible, package after drying with a desiccant material such as silica gel.

Salvage priorities

• Any iron object or component.
• Archaeological metals, especially iron and copper alloys.

CERAMICS

Facts about ceramics

The lower fired a ceramic object is, the more vulnerable it is to damage from water. Low-fired archaeological ceramics with soluble salts are especially at risk.

What to expect when ceramics get wet

Low-fired objects become soft and may disintegrate when wetted. Salt-damaged vessels may lose surface skin. Joints of reconstructed vessels may fail. (This is especially likely in archaeological ceramics that have been repaired with white glues.)

Priorities

Ceramics are generally a low salvage priority in a mixed collection. Exceptions are low-fired wares and objects with instabilities such as friable surface due to salt damage, or insecure repairs.

Drying Methods

• Pat and blot dry. Rinse in clean water if muddy or contaminated.
• Blot dry, then air dry in actively moving air (fans and dehumidifiers).
• Use a hair dryer, heater, or oven to gently accelerate drying priority materials.
• Protect broken edges from further damage.
• Be sure objects are truly dry on the interior before packing.