Attempts to speed up drying by warming the air supplied sometimes lead to trouble because the capacity of the air for moisture is increased too much and water is removed from the piece too rapidly. The relatively high viscosity of water limits the rate of flow through the capillaries below surface. Faster capillary flow is, hence a pre requisite of faster drying.
The problem can be addressed by simple solution. A rapid capillary flow is made possible by raising the temperature of the piece, while drying is checked by maintaining a high relative humidity in the air. The speed of drying can then be kept under control by controlling the relative humidity.
To be contd……………..
