In ancient China, furniture was tenon-mortise structure, so the furniture could be made without a nail, and it was very firm. So some people who don't understand it will brag that the furniture made by real ancient carpenters in China doesn't even need glue. In fact, this is completely wrong. Traditional furniture, except for some parts that need detachable function, is the glue used by ancient carpenters to glue.
Glue used by ancient carpenters mainly includes swim bladder glue and pigskin glue.
Swim bladder glue, as the name implies, is made of swim bladder. After steaming, boiling, mashing and filtering, the swim bladder glue was finally obtained. When it is used, it is heated in water, melted and coated on the surface of wood, and then it can be bonded successfully after being cooled and dried.
Pigskin glue, that is, pigskin is boiled and turned into something like glue. When it is used, it is also heated from water, which is the same as the use of swim bladder glue. Here's what pigskin glue looks like:
What are the advantages of these two kinds of glue? The first and most important thing is that nature is pollution-free. Secondly, these two kinds of glue are most afraid of being heated, so when the furniture has been used for a long time and is damaged, it is only necessary to pour a pot of boiling water on the glued place and then disassemble it. And cold water, no matter how you water it, it's okay. Unlike the chemical glue used now, it can't be removed after being glued. This is also a disadvantage!
Of course, the shortcomings of these two glues are also very obvious, so they have been gradually replaced by modern glues. First of all, these two kinds of glue are not easy to make. In particular, swim bladder glue needs to be pounded vigorously. As the old saying goes, "A good man can't pound two swim bladders", that is to say, it is very difficult to make swim bladder glue. What's more, today, the swim bladder, which was not a rarity in the past, is mainly used as a beauty and health care product, and the price is constantly increasing, so the use of swim bladder glue is even less.