When the proper glue is used and applied in accordance with the manufacturer's specifications, a glued joint often will be stronger than other parts of the material. Charts that indicate which glue works best with what materials and which adhesives work best on certain combinations of materials are available in better home-improvement centers. So, you needn't waste your time trying to remember the almost infinite number of combinations of glue and materials that are available. However, there are some tips that you should be aware of that will get things sticking and staying together in your home.
Before going shopping: Be sure to determine the types of materials being glued - wood to wood, metal to glass, ceramic to ceramic, and so forth. Real marble and cultured marble sometimes are similar enough in appearance to fool the novice. Making the wrong guess in a glue application could mean having to do the job over again.
Outdoor adhesives are water resistant and indoor grades normally are not. Read that last sentence again. "Water resistant" adhesives that are used outdoors might not be "waterproof." That's why you will want to look for a waterproof adhesive if the item to be glued will be used under water. Is there such a glue? You bet there is. Where could you use a waterproof glue at home? Repairing a broken decoration in an aquarium, a broken shower tile, or even a chip in the kitchen sink are just a few applications.
Your task is only half done once you have chosen the proper glue. The rest of the job involves its proper application. Here again, there are a few rules of the road that you will need to follow.
It is well known to most folks that a connection should be absolutely clean. But did you know that an old joint that is being reglued is not clean enough if any of the old glue remains? To remove it you can use adhesive solvent, a scraper, a heat gun, a hole grinder, a steam iron or a wire brush. Be sure the surfaces to be joined are free of loose particles and old adhesive.
Temperature is another important factor. Glue does not like cold days. Whenever the temperature drops below 70ºF, many types of adhesives will take a great deal more time to harden. Our rule of thumb for most household glue jobs is to leave the bond alone until the next day.
Another factor to consider is the type of connection to be glued. Porous surfaces like those on pottery and on the end-cut of a piece of wood should get more than one coat of glue. If the surface is porous, a single coat of glue will quickly be absorbed and none will be left on the surface of the joint to form a connection.
Trying to use glue as a filler for large gaps will more often than not result in a failed joint. In the case of a wood project, wood shavings, toothpicks and an unfinished golf tee, are a few items that can be used to shim a joint to make for as tight a connection as possible. Although wedges and shims are good for creating a tight joint, in many instances clamping devices are necessary. Tape might be all right for some connections, but for most applications a furniture clamp can make a big difference. Clamp choices are endless and the clamps can be used for other household projects. One company offers a folding work table that has a built-in clamping system.
Be sure to read the safety instructions on the glue that you will be using. Many are not only flammable, but explosive as well. In some cases adhesives can be so flammable that it is wise to turn off any nearby pilot lights.
