Glue is a mixture or substance, as well as various multicomponent compositions made on the basis of both inorganic and popular organic substances today. It is able to connect a variety of materials: paper, textiles, leather, wood, ceramics, glass, rubber, metals, plastics. Bonding is caused by the formation of an adhesive (very strong) bond between the surfaces to be joined and the glue layer. The strength of adhesive joints is also affected by cohesion to the surface of the glue. By type of bonding, adhesives are classified into drying, non-drying adhesives and binders, based on polymerizable compositions.
Consider the drying kind (its characteristics), namely the joiner glue. It includes: casein, glutin, PVA, vegetable glues and glue masses from synthetic resins.
Casein woodwork glue is a brown-yellow powder. It is made from alkali and dry fat-free cottage cheese. When cooking this powder is poured into cold (room temperature) water and stir constantly.
The ratio is 2: 1 (water to powder). By its properties, it is inferior to the fish, but it exceeds the mezdrovy.
Glutinous joiner glue is made from mezdra (skins of animals, tendons, cartilages), bones of fish and animals. It is divided by the types of substances underlying it: bone, fish and mezdrovy. Fish is mainly used for various restoration works, and bone and mezdrovy, as a rule, in the work with furniture. Most often glutinous joiner's glue is produced in the form of small dry tiles. Sometimes it happens and in barrels, but in this form quickly rot. Prepare the adhesive solution for one to two days. It is important that the remains are stored in the cold. The quality of the tiles is determined by the external state - if it does not bend, if it does not give sharp edges and has a transparent color, then this is a good tile. Conversely, the dark color of the tiles, the cut edges and the ability to easily bend it indicate a low quality. Preparation: Tiles should be poured with boiled water, cooled to 25 degrees, and wait 10-12 hours until they swell. If you pre-shred plates into pieces, you can reduce the swelling time to 2-4 hours. The swollen glue should be cooked for three hours. To prevent rotting of the glue, you can add antiseptics during cooking. When gluing, they first smear the surfaces and give them an exposure (5 minutes). Then the parts are connected and waiting for another 5 minutes. Then put the day under the press.
Glue PVA joinery is produced in tubes already ready for use. It is not washed off with water, dries quickly, but has, unfortunately, a short shelf life. Despite this fact, at the moment it is the most common among other species.
Vegetable carpentry glue has not found wide application because of weak bonding properties. For the most part, it is made from starch and is used for gluing cloth and wooden surfaces.
Adhesive masses from synthetic resins are liquid and pasty. They are suitable for wood, and for cast iron, and for porcelain. Are made more often from carbinol.