by Bob Beranek
  • facebook

Let me begin and end this post with one request. Invite your adhesive rep to visit and provide training for your technicians on what’s new with their products. Although I routinely preach the importance of cleaning glass properly to insure solid bonding, today that advice is more important than ever. There are several new procedures and products that should be introduced and put into practice as soon as possible.

Adhesive representatives and chemical engineers tell me that the number one reason for adhesive failure is improper cleaning of the surface. Adhesive companies have stepped up their training on this topic recently for good reason.

We all know that the most important area on the windshield for care in cleaning is the frit area. The frit is the black painted band around the interior perimeter of the glass that protects the urethane from ultraviolet (UV) light. It’s usually applied to the number four surface of the glass. The frit not only protects the urethane from UV light, but it also provides an additional mechanical bonding surface for the urethane to bite to. The peaks and valleys created by the frit paint application in the manufacturing process provides more bonding surface for better adhesion.

Until now, techs didn’t worry about internal frit preparation. What is an internal frit? It’s the black band of ceramic paint applied to the number 2 surface of the glass, not the number 4 surface. There is at least one manufacturer that applied a frit to both the 2 and 4 surfaces for aesthetic reasons. However, we are more concerned with the former type frit and not so much on the latter. We’ve seen internal frits for years, but until recently we didn’t know they needed special preparation.

Internal Frit

Traditional Frit

 

The preparation of the internal frit is very important to bonding success. Some use additional products to abrade/clean the surface. While others may use special procedures, such as “wet scrubbing” to clean and prep the surface for bonding. Either way, there have been changes you should be aware of and trained on accordingly.

For those of you that use primerless products, please make sure that the cleaning and prepping procedures are followed and practiced daily on every installation. Primerless products are very convenient because they eliminate a step in the replacement process which saves time and money. However, primerless adhesive installations allow no room for error when it comes to preparation of the glass surface. Any contaminants or “shortcuts” in preparation of the glass surface can result in poor adhesion, injury to your customers, and a liability for your shop.

As promised, I’m ending this post by encouraging you to invite your adhesive rep for a visit and ask them to train your techs on what’s new about their products. Adhesion standards do change and your installation procedures must change too. This is important stuff, guys. Do it.

Within the past few years there’s been an introduction of a new class of tools that I think warrants some discussion. These tools are produced by various manufacturers with names like the Rammer Jammer™, GT Tools™ Quarter Cutter™, and the Equalizer® Push Knife. These types of tools are designed to take some of the “power” away from the tool and give the control back to the technician. Think less violence and more control.

Photo courtesy of www.rammerjammertools.com

Those of us who do a lot of remove and re-installs (R&R or R&I) require the ability to remove a part without damaging it. The problem with some power tools is that without care and/or experience, the technician can damage the underside of the part or the body of the vehicle. Which can cause a poor fit or require outside repair for the damage to the vehicle’s body.

Hand tools give the technician a little more control. Though it is certainly possible to scratch a vehicle with hand tools, the severity is usually more superficial and can be remedied using adhesive metal primers or by the body shop as they fix whatever problem necessitated the R&R in the first place.

Picture Courtesy of Equalizer Tools®

Keep in mind that like with everything, there is a learning curve. You’ll have to practice the use of the tool and use more physical effort to do the job than when you use power tools. It  will also probably need a medium to heavy mallet as a “convincer’ to start the tool.

Picture courtesy of www.gtglass.com/products/gt-tools-quarter-cutter

Are these tools better than a wireout or other carefully used tools designed to cut close to the glass?  That’s hard to say.  I ‘ve heard some technicians argue that time is money and they can do a removal faster with a hand tool than with a wireout, and with less damage than a power tool. I think there is a place for all of the various options.

My advice is to research the tool and see what works for your needs. Quarter glass removal tools usually range from 12-14, 24-26 and 32-36-inch handle lengths and with blade sizes anywhere from 1-1/2 to 3-inch widths. Most of my clients use the shorter lengths more often.  So, if your budget is tight, you might want to purchase the shorter versions first and then move up when the need demands a longer one. 

I belong to several glass related technicians’ groups on Facebook and enjoy participating in discussions when I can. This past week a conversation brought back memories of my installer past and the old DW837/836 windshield. I thought I would share it with my readers this week.

The DW837/836 windshield is the windshield for a 1975-1991 Ford full-sized van. Back in the day, we used to do a LOT of them. That was our service vehicle when I was an installer. It has four-sided heavy chrome mouldings and a block size of 34×73, which makes it a large and awkward piece of glass to set by yourself. The original equipment adhesive was butyl tape.

Photo Courtesy of Purple Wave

When I did these windshields, we used round butyl to replace them. I would smear some liquid butyl on the passenger side bottom pinchweld and apply the butyl tape to the glass. Then, I set the glass onto the liquid butyl, slid it to the far pinchweld, set it in place, decked it and then back sealed the seam with a flow-grade sealant. This was a successful method because we rarely had a leak or noise complaint. The two types of butyl meshed together and sealed permanently.

Our Industry Standard says:

8.4 Whenever OEM retention systems are modified on later production models without body style modification, the most current retention system shall be used in the replacement unless otherwise specified by the OEM.

However, the Ford van never had a change to urethane until the body style changed in 1992.  Thus, the OEM specifies butyl for a Ford Van of that body style so by rights, butyl could be used.

Today our industry recommends the use of urethane when replacing these parts, rather than continuing to use inferior bonding adhesives. This is to ensure the bonding is improved and not hindered and so the replacement must be done correctly.

One of the biggest challenges for field techs is that urethane and butyl are not compatible for bonding purposes. This means ALL of the butyl must be removed for proper bonding. Unfortunately butyl tape is difficult to remove, especially if the tape is older. You then must scrape off the biggest share, and continue with one of the following to remove the rest without damaging the paint:

  • Use a sharpened plastic stick to scrape off the remainder of the tape.
  • Use a big ball of old butyl to stick to the remaining butyl and peal it off.
  • Use a solvent for removal. This would require an additional process to neutralize the solvent.

In any case, it’s time consuming and difficult to accomplish.

In a past posting I suggested the use of a tool used by collision centers to remove decals and pinstriping, called an eraser. It’s a rubber wheel inserted into a drill and used as a butyl eraser; it works well. It literally erases the butyl like pencil markings from paper without damage to the paint. The tech then dusts the pinchweld of rubberized residue, primes the pinchweld, applies the urethane to the proper height and width and sets the glass using the modern setting tools or a helper.  

This method of butyl removal is fast, easy, economical and damage free. If you give it a try you won’t be sorry.