In house conditions for wood pastings apply glue polivinilatsetatnyj marks PVA, PVA TH, PVA, kazeinovyj, synthetic joiner's, bone and epoksidnyj is more often.
Polivinilatsetatnym use glue widely. He does not demand any preliminary preparation, quickly dries and gives strong enough, but not waterproof connection.
Strong and waterproof connection can be received on kazeinovom glue. It is on sale in the form of a white powder. On 1 litre of water take 250 g dry glue which dissolve at a water temperature 60-70°Р and maintain 1,5-2 ch. Kazeinovyj glue usually prepare in the quantity necessary for use for once, as through 4-5 ch it becomes unsuitable.
Synthetic joiner's glue goes on sale in the form of two components - pitch and a hardener. A poroshkoobraznyj hardener dissolve in a small amount of hot water (an order of 100 ml) and enter into liquid pitch, constantly mixing before reception of homogeneous weight. The prepared mix should be used within 20 minutes
Bone glue - traditional glue for a tree - differs long technology of preparation.
a Fig. 9. Klejanka :
1 - internal capacity, naveshimaemaja or established on external; 2 - external capacity with the handle; 3 - water; 4 - an electric stove; 5 - glue
Bone glue in tiles or granules Is on sale. Before tile use split up and fill in with water for swelling. Granules do not demand crushing. Glue should be in water about days. After that the top sheet of water merge, and the formed jellylike weight cook, using for these purposes special or self-made klejanki (fig. 9). At work use hot glue for what constantly warm up it.
Products from wood of firm breeds stick together liquid glue, and for wood of soft breeds use more dense. To check up density of glue, in it lower a brush and lift over bankoj; glue should flow down from a brush a continuous appeared through stream. Too dense glue falls slowly, clots, too liquid - quickly flows down.
For protection of bone joiner's glue from rotting at long storage in it it is necessary to add a pinch of boric acid.
Universal glues with which it is possible to glue various materials including a tree, are epoksidnye glues - EPO, EDP, epoksidnaja shpatlevka. They form strong and waterproof connection. However because of high cost these glues for bolshego amount of works are not suitable. Besides, at work with them thorough training of stuck together elements is required.
In small amounts for pasting of separate details it is possible to use also glues "+ую" "-ѕсюъ" БФ-2, "¦рЁё". Except listed, synthetic pitches, which otverzhdajutsja are issued by the industry also at a room temperature: КБ-3, SFH, ФРФ-50, ФР-12, ФР-100. For pasting of wood or plywood with bumazhno-layered plastic, fibreglass and other materials use epoksidnye and polyester glues, and wood and metals - glues 88Н, 88НП, "¦юьхэ=-1" КР-1, "Ихэшъё".
At pasting it is necessary to be guided by following key rules:
- connected planes should be carefully adjusted to each other;
- for the best pasting surfaces need to give a roughness;
- it is possible to stick together only well dried up wood;
- stuck together surfaces should be degreased, and also are cleared of pollution or traces of old glue;
- glue it is necessary to put a uniform layer gear shpatelem with small teeths, a fragment nozhovochnogo cloths on metal, rubber shpatelem;
- for reception of a strong seam it is necessary to put glue on both stuck together planes;
- maintain stuck together details under a press.
The Overall objective of this operation - uniform distribution of pressure on the stuck together area.