MINNESOTA HISTORICAL SOCIETY
SALVAGE OF WATER DAMAGED COLLECTIONS
BLUEPRINTS
| Priority: | Air dry or freeze within 48 hours. |
| Handling Precautions: | Do not separate single sheets but interleave the folders every two inches with freezer paper and pack. Place additional freezer paper on the top and bottom of the stack to prevent the wet folder from being in contact with the blueprints. (Caution - do not use acid-free buffered paper as alkaline solutions dissolve prussian blue pigment.) |
| Preparation For Drying: | Sponge standing water out of map drawers. Remove the drawers from the cabinet, ship and freeze them stacked up with 1 X 2" strips of wood between each drawer. Pack loose, large prints in bread trays, flat boxes, or on plywood covered with polyethylene. Bundle rolled maps very loosely to go boxed in small numbers to the freezer, unless sufficient freezer space is available for items to be unrolled. |
| Drying Methods: | Vacuum freeze drying is best since it causes the least dimensional distortion. Freeze drying is the second choice and air drying third.
Vacuum freeze drying and freeze drying will have to be performed by a vendor since it requires highly specialized equipment; see Appendix 2 for a list of vendors. Air Drying requires a space away from the disaster area which probably has high humidity. Lay material out on tables. Air must be continuously circulated as the material dries. See PAPER: uncoated for a more detailed description of drying methods. |
Minnesota Historical Society Disaster Preparedness Plan 6/93