Dowels

Binding technique is the science everybody with a house, flat or holiday house has already encountered. They may not have used the scientific term when they were drilling a screw to hang a picture or a clock, when they were installing the soap or towel holder – possibly, the heater –, or  when they were trying to wainscot the dining room. The goal is always the same: fix that thing – there are several possibilities, though, and only some of them are appropriate. When choosing the optimal binding technique, one has to consider the building material, the degree and direction of the load, and all the other expectations towards the binding material. We would like to give some help in the following. 

First of all, it is essential to know what materials the walls, the flooring and the ceiling are made of. The walls can be made of light and normal concrete. The light concrete is composed of cement plus light additional substances (pumice, styropor, etc.), which means that it can bear a lot less load than the normal pebble concrete. Another extensive group of building materials are the dense and the porous masonry materials. Both the dense (1) and porous (2) materials can be either dense or hollow in structure. A third, separate group comprises the different sheet materials: plasterboard, wood chips, hardboard, and other boards of various materials.

To start with, one has to know which building material they are going to work on, and which of the above category it is closest to. It is especially important because the drilling technique of the wall depends on the material. Without going into the details, it can be confirmed that almost all wall types can be drilled with hard carbide-tipped drilled, what is more, most of them can be drilled only with this type. When drilling normal concrete, always switch on the hammer drill function, otherwise one will not get the result one wishes. With other materials, first try without hammer drills, and use it only if really necessary. One normally should not use high speed when drilling walls. It is also important to decide on the appropriate drilling depth, so one should use a drill with the relevant function.

The base material of binding technique is the dowel, produced in virtually infinite variations. However, its mechanics can be explained with three modes of effect. The most common is friction closure (3), when the dowel is expanded within the drill in some way or another, its external surface is pressed to the drill wall with great force, and friction prevents the moving of the dowel.