Animal_glue

An animal glue is an adhesive that is created by prolonged boiling of animal connective tissue[1]. These protein colloid glues are formed through hydrolysis of the collagen from skins, bones, tendons, and other tissues, similar to gelatin. The word "collagen" itself derives from Greek kolla, glue. These proteins form a molecular bond with the glued object. The glue is applied hot, typically with a brush or spatula; it is kept hot in a glue pot. Although animal glue was once the dominant type of glue, it has largely been displaced by synthetic adhesives; today it is used primarily in speciality applications.

Stereotypically, the animal in question is a horse, and horses that are put down are often said to have been sent to the "glue factory"; this may be literally true. Glue is also produced from other animals.

Types and uses

Specific types include hide glue, bone glue, fish glue, rabbit skin glue. Animal glue is still extensively used in lutherie, pipe organ building, and antique restoration.

• Hide glue is used in woodworking
• Hoof glue is also used today in woodworking, specifically cabinetry
• Rabbit-skin glue is used in the sizing or priming of oil painters\' canvases.

Most animal glues are soluble in water, useful for joints which may at some time need to be separated. Alcohol is sometimes applied to such joints to dehydrate the glue, making it more brittle and easier to crack apart.

History

Nearly 5,000 years ago, the Egyptians were using hide glue for their furniture adhesive. This is proven by hairs found in Pharaoh\'s tombs and by stone carvings depicting the process of gluing different woods. Evidence exists that the Sumerians also used glue before the Egyptians did.

See also

• Adhesives

References

• Patrick Spielman. Gluing and Clamping: A Woodworker\'s Handbook. Sterling Publishing, 1986. ISBN 0-8069-6274-7

This article is licensed under the GNU Free Documentation License. It uses material from Wikipedia