Any home repairman knows there are times when nails are not enough to hold things together. It's at those times that he reaches for the glue and clamps. But there is more to bonding two materials than dribbling glue and pressing down. Equally important are the choice of adhesive and the method of clamping the two pieces together.
Anyone who peruses the rows of adhesives displayed in local hardware stores knows that the days of library paste and mucilage are over. When choosing an adhesive, read the labels to find one that is suitable for the job at hand. Be sure to read the label all the way through. Some adhesives are water-soluble and suitable for craft work and children's art work, because they allow sticky fingers to be washed after use.
Most adhesives, however, are so strong that they should be used only while wearing gloves. There are several that are so efficient that a single accidental drop can bond fingers together.
Take care with all adhesives that they do not come in contact with the eyes or skin. Most should be kept away from children, and many must be used only with adequate ventilation.
Generally speaking, there are two kinds of adhesives available in addition to the all-purpose Elmer's Glue, with which so many of us are familiar: epoxies and non-epoxies.
Vinyl non-epoxies are good, generally, for porous materials, such as model-building parts, foam-type products, paper, and cloth. They can be used for labeling, photography, bookbinding, and light cabinet work and require only a slight pressure to bond.
Epoxies, on the other hand, are tougher and must be used with greater caution. They are good for all these jobs as well as such difficult jobs as weatherstripping and rubber insulation, laying down bathroom tiles subject to constant steam and water, installation of laminated countertops, and fixing broken dishes that will be subjected to dishwasher steam and heat.
Jobs that require epoxy will usually require clamping to make a permanent bond.
Loose chair joints and rungs are frequently a home handyman's nemesis. Regluing and clamping them is often awkward and unhandy.
First, the rung should be completely removed, if possible, and all the old glue removed, because a stronger bond is always made if new glue is applied to clean wood. If the rung is impossible to remove, a small hole can be drilled into the joint for the injection of glue with an oilcan or similar device.
One of the best ways to clamp this all together is with a one-inch circular strip cut from an old inner tube from a bicycle, automobile, or truck tire. The elasticity allows the strip to stretch around the rungs and then tighten to hold them firmly in place.
If an elastic strip is not available, the joint can be clamped by circling it with a rope, which can then be tightened with a pencil, screwdriver, or dowel stick used in tourniquet fashion.
There are also products on the market, not adhesives, that can be used successfully on chair joints. By expanding the wood fibers, they swell the rungs so that they fit tightly into the sockets.
Large jobs usually require the use of heavy metal clamps which can be purchased at a hardware store. There are C-clamps (so-called because they are made in the shape of a letter C) in sizes up to about 8 inches. They are tightened by a screw arrangement.
Larger jobs will require pipe or bar clamps. A shop vise can often be used in place of a clamp for smaller jobs. Just remember to set the clamp at right angles to the glue line.
It is important never to put clamps directly onto the piece being fixed, because the pressure will often mar the surface of the material. Use pieces of soft wood, such as balsa, between the clamps and the finished material. These are called shims. Heavy felt or heavy cardboard can also be used to protect the finished surface from marring.
Watch that any excess glue, which will be squeezed out by the pressure of the clamp, does not mar the finished surface. The excess glue, which you should wipe away immediately, is proof that you have used enough adhesive. And always use maximum pressure for maximum-strength bonding.
For clamping small objects, sturdy rubber bands can often be used in many innovative ways. Don't be afraid to improvise, as long as you get adequate pressure for bonding. A rubber band and clothespin or a rubber band and a pair of pliers can often be used in small gluing jobs. Masking tape will often apply pressure in the proper places on small jobs as well. Sometimes, when the proper clamp is not available, a finishing nail can be used to set the bond. It will also serve as a reinforcement.
The home handyman may sometimes have odd-shaped pieces to work with that cannot be clamped. Often the best way to handle this type of material is to make a jig, or reverse image, of the pieces to be glued. Then set the clamps onto the jig. A home handyman can make the jig with wood.
Above all, don't be afraid to be creative in fashioning the proper clamp. With the right adhesive and maximum pressure, the bond is sure to hold.