Talk:PMG Humidification, Drying and Flattening

Forced air section removed until such time as it is deemed appropriate for photographs. May be more appropriate for PCC section. SBW July 5, 2016

Variation #4: Blotter stack with added air flow using vacuum or a blower (drying by forced air)

• Basic configuration:
  Drying by forced air is achieved by pulling air through a stack with corrugated board and porous synthetic contact materials. This method was adapted by the conservators at the Legion of Art in San Francisco, CA, USA from one developed and used by the employees of Crown Point Press in San Francisco, CA, USA for drying large paper prints. "The drying speed is regulated by the configuration of the stack materials with respect to the dimensions and position of the air channels, and the air velocity and temperature." (Banik and Brückle, p. 412).
  Basic configuration is:

- corrugated boards - blotter - porous synthetic contact materials - photograph - porous synthetic contact materials - blotter - corrugated boards A blower (can be heated if desired) or vacuum hose is attached to a rectangular funnel the width and depth of the stack or a flexible cover that can fit over one end of the stack. The corrugated boards are cut with flutes oriented to the blower or vacuum's source.

• Variations:
• Pros:
  • Limited materials are used and can be potentially reused.
  • Quicker drying process because of air flow.
  • Efficient method for batch flattening large numbers of photographs of the same or similar size and general condition.
• Cons:
  • Uneven or fast drying can create cockling (Banik and Brückle, p. 412)
  • Corrugated boards may impress on photographic emulsions.
  • Use of electrical energy is needed to sustain the blower or vacuum. A potentially "un-green" or environmentally friendly approach, depending on the source of electricity.
• Tips:
  • The original Crown Point Press air drying system article has insights into this method and tips for making and adapting a unit.
  • Another example is shown in Water and Paper: A Guide for Conservators, (Banik and Brückle, p. 412).
  • The system's effectiveness can be "increased by sealing the sides with plastic foil" (Banik and Brückle, p. 412).

• Porous synthetic contact materials can be used in restraint drying with forced air to wick away moisture.
  • Tek-wipe is "a non-woven blend of 45% polyester and 55% cellulose hydrospun" (from Polistini website, 2016).
  • Paraprint OL 60, non-woven viscose fabric reinforced by acrylate binders. See Huhsmann, Enke and Ulrike Hahner, 2007. "Application of the Non-woven Viscose Fabric, Paraprint", Restaurator, p140-151