by Bob Beranek

I pride myself on always looking for the answers to the question “why?” Whether an issue comes up during one of my training sessions, via a customer interaction or through a colleague’s inquiry, I’m always searching for the reasoning behind a directive. Due to my time in the industry, I know many answers but I am not a “know-it-all.” I am frequently researching and seeking the truth. Lately, I have been thinking about the installation procedures I have witnessed or heard about that have stumped me. Maybe you can fill me in.

Why does an installer lay a round bead from six to eight inches off the pinchweld? This one has always bothered me. Every time I ask an installer this question, he has the same answer, “That’s the way I was taught.” Really? He was taught to do that? Why? To me it is clearly “showboating.” What possible benefit do you get from holding the caulk gun off the pinchweld and laying a round bead?

Following this method could cause you to bridge a low spot on the pinchweld, thus possibly creating a leak. The bead could separate and leave a gap or worse yet, fall onto the dash or interior mouldings and make a terrible mess. In my opinion, this method of application has no redeemable benefit. If you see an installer applying urethane in this way, please stop him and ask him why he does it. I would love to hear a good reason.

Why does a technician spank the glass into the urethane? I know that in the old days, butyl was used as the adhesive of choice and spanking the glass helped to meet the dense adhesive to the vehicle frame. However, the new liquid urethane does not need the beating of the glass to “wet out” and create the seal. A steady smoothing action is much better and much less violent. Plus, the beating of the glass could cause fracture or the stringing out of the urethane, causing a leak. There was once a relatively reasonable explanation for this practice, but it no longer makes sense.

Why do automotive glass installers still set the glass with their hands instead of vacuum cups? The number one reason given to me is that the technician doesn’t trust the cups to hold the glass securely. Show me a technician that doesn’t use cups and I’ll show you a technician that was given or purchased cheap ones. Or, once given good ones they didn’t take care of them. There are a couple of rules when using cups:

  • Place them on a smooth, clean, flat glass surface. Don’t put them over a sticker or crack. If you do, the air can seep under the cup and cause release.
  • Make sure that when storing your cups, you place them in their proper holders, every time. If cups are thrown on the floor of your service vehicle, the debris can cut or gouge the seal of the cup, thus rendering them worthless.
  • Keep the sealing rubber of the cup and any “O” rings supple and lubricated. If the rubber on the cups is allowed to dry out or dry rot, the cups will need repair or replacement. However, if taken care of, they can last a long time.

I’m sure that many of you out there also have some “whys” to get answered and I’d love to help. Don’t hold back. When you see a procedure or act that appears unusual or interesting, ask the simplest of questions. Why?