Mouldings, usually spelled without the "u" in the United States*, have become an integral part of most automotive glass installations. Whether it is due to the increasing trend toward mobile installation or simply the reluctance of the shop owner to turn up the heat, technicians are often forced to work in the cold. Making the proper decisions with respect to mouldings can help a company save time and reduce costs while still addressing safety and structural integrity issues.
When determining if it is safe to install glass in a car, one simply has to look at the limitations of the adhesive being used. All adhesive companies will explain the temperature and humidity requirements of its products clearly. Usually, mouldings are nothing more than decorative trim and are not part of the structural integrity of the vehicle. However, mouldings can destroy the structural integrity of an installation if used incorrectly.
In the past few years, the use of "channel" mouldings has become prevalent. These mouldings go on the glass prior to installation and part of the moulding actually covers the inside portion of the glass. It is extremely important that the adhesive is applied directly to the glass and in sufficient amounts. If instead it is applied to the inside lip of the moulding, the installation will be contaminated. Therefore, when selecting a moulding it is a good idea to try to choose one where the inside lip is not too large.
The first question to ask when selecting a moulding for a cold weather installation is "does it remain flexible in the cold?" Much time is wasted when it is necessary to use a heat gun to make a moulding manageable. Sadly, the heat gun will continue to be needed for some cars requiring the use of original equipment mouldings. In the aftermarket, there are more options. Every aftermarket company claims their mouldings remain pliable in low temperatures. My suggestion is test them for yourself. Before leaving work, put a small piece of moulding in the freezer. If in the morning you are not satisfied, try a new moulding.
Many mouldings today utilize butyl in their channel so they adhere better to the glass than mouldings without butyl. In colder temperatures butyl loses some of its "tackiness." Therefore, it is a good idea to check how well the butyl sticks to the moulding. The following is a good simple test. Put the moulding on the glass then pull it off. The butyl should stay in the moulding, not on the glass.
Probably the most significant attribute to a good cold weather moulding is its resistance to large temperature changes. Some mouldings will expand and contract with changes in temperature. There is nothing more frustrating than doing an installation over because of moulding problems. When poor quality mouldings shrink in the cold, the corners lift off and there are gaps where the moulding meets on closed loop installations.
This winter, every glass shop should do the research necessary to find the mouldings that give the best bang for the buck.
*USGlass style uses mouldings to denote auto glass mouldings as distinguished from door and window moldings.
Joseph Gold is vice president of Gold Glass Group Corp. in Bohemia, NY.
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