Different Types of Clamps and How to Use Them

Many do-it-yourself tasks require two or more sections of a workpiece to be held together temporarily while a more permanent fixing is made, often with glue. A variety of clamps is available for this purpose, many of them with specific uses. Keen woodworkers may make their own clamps (or cramps as they are often called) from scrap wood or other materials.

Commonly used clamps
The most common clamp in the workshop is the G- (C-) clamp. This is a general-purpose tool that is available with a variety of throat sizes. It may be used on its own or in conjunction with others when, for example, working on the surface of a wide board or holding boards together for gluing.

The sash clamp was specifically designed for assembling window frames, or sashes, but it is also often used when edge-jointing boards to form large panels for table tops and similar items.

Sometimes, it is useful to be able to apply a clamp with one hand while holding the workpiece in the other, which is when the singlehanded clamp conies into its own. It works on a simple ratchet system, rather like a mastic (caulking) gun.

For picture framing and heavier items with 45-degree mitres at the corners, there is the mitre clamp. This can be quite a complex affair with screw handles or a very simple clothes-peg (pin) type arrangement, that is applied very quickly.

Special-purpose clamps
There are many of these, but one that the do-it-yourself enthusiast may find useful is the cam clamp, which is wooden with cork faces. This is a quickly operated clamp often used by musical instrument makers. Its advantages are its speed in use, its lightness and its simplicity. The cam clamp is ideal for small holding jobs around the home, although it cannot exert a great deal of pressure.

Another useful standby is the web, frame or strap clamp. This is perfect for holding unusually-shaped items, which can be pulled together from a single point.

They are most commonly used to join coopered work, such as barrels and casks, or multi-faceted shapes such as hexagons or octagons used in decorative frames and mirrors. The components to be joined usually lie flat on a horizontal surface.

Clamps in use
Apply pressure to a joint or the assembly you are working on as soon as possible after gluing – make a habit of preparing everything you need in advance. Keep a box of small scraps of wood handy and use them to protect the surface of the work. It is often said that you can never have too many clamps, and you will soon start collecting a selection of different types and sizes to suit all kinds of assembly technique. Many of these you can make yourself.

Practical tips
– Do not be tempted to release clamps too quickly. Be patient, allowing plenty of drying time for the glue.
– Think through the sequence for the clamping process and make sure you have enough clamps to hand before you apply any glue. You may decide you need another person to help.