Surfaces must be clean, dry and free from all defective and poorly adhering material, dirt, grease and salts. Dry sanding, flame cutting and/or welding of the dry paint film will give rise to dust and/or hazardous
fumes. Wet sanding/flatting should be used wherever possible. If exposure cannot be avoided by the provision of local exhaust ventilation, suitable respiratory protective equipment should be used. It is essential to remove cellulosic-based products, lime or watercolours that exhibit interlayer
cohesion failure or have been detached. In that case, it is advisable to use mechanical means or wet and scrape the surface with a knife. For either new or already painted surfaces with watercolour, apply FIT HYDROCHROMA, thinned up to
20% with water for the first coat, and up to 10-15% for the second.