Stuck Together Like Two Dogs

Has this ever happened to you? Lord Knows it has happened to me a few times. It is no fun, let me tell you. No amount of pulling seems to help. Once, I used a pry bar and a putty knife to get it free but I broke it. I also tried generous amounts of lacquer thinner poured into the crack followed by some vigorous scraping. This actually works but it is very messy and you might cut yourself. No really. It is such a powerful union, great care must be taken from the very start to be sure that the end result is pleasant. Contact cement is some great glue with many applications but it is primarily used for laying up plastic laminate. There was a fellow at work who used to glue the soles of his shoes back on with it! Here are a couple of tips for making your project go smoothly: First, make sure you allow plenty of overhang. Cut the laminate (or whatever you wish to bond) about a half inch bigger all around than the substrate. After coating both the substrate and the laminate with cement, let it dry thoroughly. The main reason contact cement joints fail is because the glue wasn't dry enough when the pieces were laid together. With most contact adhesives, you have about a one hour window to work with. Don't rush it. Arrange some strips of wood over the already coated and dry substrate in order to keep it and the laminate separate. This will allow you to perfectly position the laminate, even if it is very large. Lift the laminate at one end, pull out a few strips and press the two parts together. Continue removing strips and pressing the parts together, then roll with a laminate roller or pound it down with a hammer and a block of wood. Plastic laminate requires that much pressure. Materials like cloth benefit as well but it isn't as crucial. Trim off the excess and you're done. I've always used the volatile solvent type of cement but there are water based non-flammable ones on the market today. If you use the volatile kind and need a break from laminating, put your brushes or rollers in a pail of water. This will keep them pliable. Just wipe the water off with a rag before dipping your brush back in the cement. I'm a big fan of aerosol contact cement. It is more expensive but the time saved is worth it, just make sure the spray tip is clean after each use. Many people use contact cement for veneering but in my purist opinion, it is a faux pas, which could end up ugly because contact cement "creeps." In other words, it will allow the two parts to shift if exposed to constant pressure. Have you seen square edged counter tops with the laminate hanging over the edge or pulled away from it? This is the reason: The substrate and laminate expand and contract at different rates and the glue is weak enough to allow it to happen. Contact cement should never be used in structural applications because of this fact. If you want your wood veneered project to become an antique, use wood glue and a proper pressing technique, either with a veneer hammer, press or vacuum bag. Glossary: Laying up - A common term used in the trade to describe the process of lamination. Plastic laminate - Many times referred to as Formica, this is the durable surface of many inexpensive counter tops. Formica was invented in 1912. Substrate - In this instance refers to the material to which the laminate is bonded. Laminate roller - a small tool designed to apply maximum pressure by rolling its rubber roller over the surface of the laminate. Volatile solvent - For our purposes, it is usually a very smelly liquid which evaporates from the glue, leaving only the binders. Structural applications - Such as laminated beams - see Glulams. Veneer hammer - Essentially it is a squeegee, not a hammer at all. Vacuum bag - or vacuum press, is just a big bag made of thick plastic in which the parts to be veneered or laminated are placed, then clamping pressure is applied by extracting the air from the bag. Press (veneer press) - This is the way veneering has been done on flat surfaces for centuries. Basically, it consists of a whole bunch of screws arranged to apply even pressure over a wide area. Here are some pictures.