Bone glue

Bone glue, also known as hide glue or animal glue, is a type of adhesive derived from animal collagen, typically obtained from the bones, hides, and connective tissues of animals. It has been used for centuries as a versatile and reliable adhesive in various applications, including woodworking, bookbinding, and restoration work.

To produce bone glue, the raw materials, such as bones or hides, are cleaned, crushed, and soaked in water. The mixture is then heated, causing the collagen to break down and dissolve in the water. After straining out any impurities, the liquid is evaporated, resulting in a gelatinous substance that solidifies into a hard, brittle form upon cooling. This solidified form is the bone glue.

Bone glue offers several advantages as an adhesive. It has excellent adhesion properties and creates a strong bond between different materials, such as wood, paper, and fabric. It also has a relatively long open time, allowing for adjustments and repositioning before the glue sets. Additionally, bone glue is reversible, meaning it can be softened and reactivated with moisture and heat, which is advantageous for restoration and conservation work.

In the context of traditional Italian lime plaster and stucco, bone glue has been historically used as an additive to improve the workability and adhesion of the plaster mixture. It helps to enhance the cohesiveness and durability of the plaster, allowing it to adhere well to various surfaces and resist cracking.

Bone glue has been valued for its natural and traditional properties, and it continues to be used by artisans, craftsmen, and restoration experts who appreciate its reliable bonding capabilities and historical authenticity.