Le Soleil publishes again this year a series of texts on cabinetmaking. In everyday life, you touch wood to call luck. In this section, we will touch it to make furniture and other delicate and ornate objects. Touching wood is like entering the wake of cabinetmaking. From the basics. This, with the help of two cabinetmakers and teachers, one, Éric Thériault, specializing in ornamental sculpture; the other, Pierre Pagé, in finishing.
Fish glue? A shoe with that?
No, this is not a joke. And that’s not all, we can continue in the same vein: nerve glue, bone glue, rabbit skin glue, lark! Moral of this story? White glue is a recent glue which does not have all the advantages.
The white glue “sets” quickly. In the case of a handyman alone at home, who has only two hands, this speed of taking can quickly become a nightmare. Before he has succeeded in installing the entire clamping device, the pieces of wood are already fixed with glue. Solution: fish glue. This glue gives you a range of assembly time of several minutes before becoming “sticky”. It requires around 12 hours of tightening.
White glue does not wash after it dries. Warning! All glues stain wood. A stain of glue which may seem invisible to the naked eye and which has not been removed will manifest itself when coloring and applying the primer (varnish, oil, wax, etc.). Just like all surface preparation errors (machining traces, quality of sanding, etc.). Animal glues (fish, bones, nerve, rabbit skin) are washed with a generously wet cloth, even when dry. Do not forget that to standardize the absorption of the future finish, all the wet parts will have to be re-sanded.
An adhesive that can be removed by any means (water, heat) is said to be reversible. Animal glues are reversible with water, some are even reversible with heat (bone, nerve, rabbit skin). Several can only be applied hot, that is to say reheated in a water bath at very low temperature.
Fish glue is the only one that can be applied cold. The reversibility of animal glues can become a drawback during water damage. Still it will be necessary that the water stagnates during a good period to come to an end. And regarding their solidity, animal glues are as resistant as white glues.
These reversible glues are mainly used today by restorers of works of art (paintings, furniture). They are therefore used not only for the sake of authenticity, respect for the original materials chosen by the craftsman, but also for reversibility, in order to eventually allow the restoration to take off (because we will have found the missing piece, because that future technology will allow better restoration, etc.). The backgrounds, as much in paint (on linen) as in painted furniture, were made with rabbit skin glue. The inlays that adorn furniture from the 17th to the 20th century were fixed with a mixture of bone glue (hard and brittle) and nerve glue (soft and elastic).
Animal glues are an inexhaustible subject. For more information, we invite you to consult the Articles section of our website. We will finish with this anecdote: André-Charles Boulle, the most famous cabinetmaker in Western history, under Louis XIV, mainly used a fish glue made of swim bladders from sturgeons from the Caspian Sea … Just that!