Types Woodwork Glues
What are the Different Types of Glues?
By far the best, and perhaps the hardest work in wood joining is done by gluing. Anybody can finish an ordinary gluing job without much thinking or pain; but a proper, enduring joint, stronger than even the wood itself, is possible only if, firstly, the proper glue is chosen and, second, the glue is properly applied.
The efficiency of a glued joint is decided by (1) kind of wood, (2) its moisture content, (3) type of joint, (4) precision where contact surfaces match, (5) kind of glue and the technique of its preparation, handling, and application, 6) level and length of pressure used when setting, (7) process of conditioning glued joints, and (8) service conditions.
Generally, heavy woods are more difficult to glue than light woods; hardwoods are more laborious to glue than softwoods; and heartwoods are harder to glue compared to sapwoods.
All eight types of glue commonly used are commercially available. Of these, the first six are especially useful for the home carpenter: (1) liquid glue, (2) blood- albumin glue, (3) casein glue, (4) synthetic resin glue, (5) vegetable glue, (6) rubber compounds, (7) cellulose cement, and (8) animal glue. There are numerous prepared glues on the market that are easy to use, but the hobbyist would want to know about some of the glues utilized by professionals.
The most acceptable glue for the home craftsman is the plastic-resin type. It comes in powder form to be mixed with water as required. This glue is waterproof, doesn't stain, and is easily managed.
Liquid glues come ready to use, and are usually quick-drying. Casein glue, made from cow's milk, is in powder form. It gets effective when mixed with water and left to stand for a short time. When dried, it's water-resistant. Animal glues, made mostly from hides, come in twenty-one various qualities. None of them, nevertheless, is water-resistant.
Blood-albumin glues, soluble in a particular solution, are not typically available for home use.
Vegetable and resin glues are soluble in different solutions; they also are not normally satisfactory for home use.
Animal glue is applied hot. Fish and vegetable glues are normally liquid glues used cold. A hot glue can be turned into a slow-setting cold liquid glue by putting either nitric, hydrochloric, or oxalic acid to it. (These acids are active and demand great caution in their use.)
Casein-glue and resin glues are available as cold-water glues. Resin glues, being waterproof, are excellent for all marine work. There are also a lot of commercial liquid glues that can be used for small quick repairs. Shellac, while not a glue, is quite useful for sticking paper, rubber, felt, lass, and the like to wood.
Cold glue comes in liquid form and is worked on room temperatures. Typically made from processed waste parts of fish, it bears the big advantage of being constantly ready. Cold glue, however, isn't as strong and sets slower than hot glue. This, naturally, has the advantage of allowing mistakes to be corrected. Cold glue must be put on in stages. Each piece must first get a thin coat of glue that is permitted to sink into the grain and dry almost entirely. Apply a thin second coat on both surfaces. Let the second coat dry till it feels "tacky"; then bind the two surfaces together, taking out excess glue as the clamp is tightened. Avoid an overly tight bind since this would squeeze out too much of the glue. Most cold glues require, at the least, twenty-four hours to harden and set.