Calcium Driers
Accelerates the drying time for oil colours and mediums. ‘Through-film’ drier.
Concentrated calcium carboxylate siccative in mineral spirits.
Calcium driers do not react on their own but in combination with other reactive siccatives such as Cobalt Driers. Used to equalise stresses in drying rates within thick paint films to prevent surface wrinkling.
Use sparingly as its over-use will destroy paint films.
Constituents
Calcium Driers (concentrated calcium carboxylate), White Spirit.
Product code:
032
Calcium Driers Product Information
Product Application
Langridge Calcium Driers should added to cobalt driers prior to being added to oil colours, oil mediums and drying oils in recommended measured quantities. Calcium driers do not react on their own but in combination with other reactive siccatives such as Cobalt Driers. Used alone, Calcium dryers will not fully dry and the paint film may remain tacky.
Calcium driers should be measured prior to use and used in trusted recipes as to avoid overuse and embrittlement of paint films. They improve the ‘through-film’ drying of oil paint.
Excessive dosage may lead to issues such as brittleness or colour shift in the paint film over time.
Add Calcium Driers at 1% of oil/medium total.
Problems with ambient temperature and humidity
Because artists drying oils (oils that dry to a hard, non-reversible film) absorb oxygen to harden, so the ambient temperature and humidity have an effect on the speed and success of film hardening.
Oils, oil paints and oil mediums should not be applied in temperatures below 10° F or above 40° F.
Relative humidity level should not exceed 50%. Moisture in a high humidity environment will create a fine layer of water on top of the paint film preventing oxygen from being absorbed. This will dramatically slow the hardening of the oil, potentially weakening the paint film even when fully dry.
Temperature and relative humidity can be controlled in the artists studio with heating/cooling devices and the use of dehumidifying devices.
Accelerating the drying rate of a completed painting
Calcium Driers should not be applied to a painting to accelerate the drying of an already laid paint film.
If a painting is taking longer to dry than is expected, it is recommended to place the artwork in a dry, warm, dust-free area with a steady airflow across the surface.
Once paint has been applied to a painting no attempt should be made to add driers or rapid drying mediums on top to accelerate drying. This can lead to cracking and potential flaking of the paint film.
Accelerating the drying rate of varnishes
Calcium Driers cannot speed the drying of artists’ varnishes as they contain no oil. Artists’ varnishes dry by evaporation of the solvent. If a varnish remains tacky for longer than is recommended by the manufacturer, this may be due to latent solvent trapped in the preceding paint film. As it attempts to evaporate through the surface it will solubilize the resin of the varnish. Place the artwork in a dry, warm, dust-free area with a steady airflow across the surface.
Thinning
For best results thin with Artists White Spirit. However, Langridge Low Toxic Solvent may be substituted.
Appearance
Langridge Calcium Driers is a light amber colour liquid with characteristic White Spirit odour.
Clean Up
Clean measuring containers with Artists White Spirit. Langridge Low Toxic Solvent may be substituted.
For further washing apply a small quantity of Marseille or other pure olive oil soap to release any remaining colour. Wash thoroughly in warm water. Leave to fully dry before using for oil colours.