Glass review

Dec. 4, 2015
Most shops continue to send the majority of their glass work, especially windshield replacement, to outside businesses. Maybe it's time your shop reconsidered and moved these repairs in-house. Refer to the following basic glass replacement steps (supplied by 3M) to help you decide if this work is right for your shop.

Nearly 15 years ago, the automotive glass installation market was going through the kind of turmoil similar to what collision repairers were also experiencing. Independent glass shops were having to close their doors because they could no longer compete with large franchise operations. They simply didn't have access to the cost structures the franchises enjoyed. They often paid significantly more for the same supplies used by franchisees, causing their customers to go elsewhere for lower prices.

During that same time, body shops also were contending powerful market forces, namely insurers who were able to largely dictate labor costs and repair procedures. Shops able to contend with these business parameters were able to survive. Many others, just like many independent glass shops, shuttered their operations for good.

Today, both markets are remarkable stable, with collision repairers actually thriving. The two industries also have diverged in one crucial area: repair complexity. For the most part, as vehicles have become more complex, collision work has become more sophisticated. Glass repair and replacement, thanks greatly improved tools and products, has become more accessible.

Most shops continue to send the majority of their glass work, especially windshield replacement, to outside businesses. Maybe it's time your shop reconsidered and moved these repairs in-house. Refer to the following basic glass replacement steps (supplied by 3M) to help you decide if this work is right for your shop.

Windshield replacement

Step 1. Glass removal. Apply protection to the interior surface area. This is necessary to prevent damage to the area and the buildup of debris when the urethane is cut and the glass removed. If the glass is already damaged and could break upon removal, you'll need to add additional protection.

Remove both the wiper blades and the cowl panel. Next, remove the window molding. With the appropriate tool, cut the urethane bond. Note: New electric cutting tools can help cutting times and make this step more efficient and potentially less damaging to the repair area. Remove the glass.

Step 2. Prepare the area. Clean the pinchweld area of all loose pieces of urethane.

Dry fit the new glass, using masking tape to mark the proper alignment. Cut the masking tape and remove the glass.

Step 3. Pinchweld inspection and preparation. Close-cut the old urethane down to a thickness of

1 – 2mm. Clean the area with water and a clean cloth. If necessary, apply primer to any bare metal scratches and allow to dry for 5 –10 minutes.

Step 4. Clean and prepare the replacement glass. Clean glass with glass cleaner and a clean, lint-free cloth.

Step 5. Apply primer. First check the expiration date on the primer. Shake the primer can well. Apply a continuous layer of primer to the new windshield. Allow 5 –10 minutes for the primer to dry fully.

Step 6. Apply urethane and install the windshield. Check the expiration date on the urethane to ensure it is still usable. Apply a bead of new urethane to the old urethane on the pinchweld. Apply at a 90 degree angle. at an application angle. Paddle all of the  joints/gaps in one direction.                          

Step 7. Reinstall the moldings and panels, and reconnect any electronics. Clean off any excess urethane. Keep the vehicle out of service until the urethane builds strength according to the manufacturer's recommendations.

(Photo courtesy of ICD Coatings) With the proper licensing, training and tools (all readily available), nearly every shop can begin performing all of its own glass work. (Photo courtesy of Auto Glass Cheyenne) Replacing most movable glass involves sticking to detailed repair steps and making use of gloves and other protective wear to avoid injury to the technician.

Stationary side glass replacement

Step 1. Remove the glass. Remove the necessary interior trim pieces and carefully disconnect any electronics. Next, remove the molding. With the appropriate tool, cut the urethane bond. Note: Again, new electric cutting tools can help cutting times and make this step more efficient and potentially less damaging to the repair area. Remove the glass.

Step 2. Prepare the damaged pinchweld.  Remove all of the old urethane only from the damaged area. For the undamaged pinchweld, leave the urethane intact for the time being.

Step 3. Add additional surface protection to the repair area, if needed. Doing so will save time and additional costs in the end.

Step 4. Prepare the new pinchweld. Scuff the pinchweld area with general purpose scuffing pad. Next, apply a two-part epoxy primer. Finish by masking off the pinchweld for top coating.

Step 5. Dry fit the glass, using masking tape to mark proper alignment. Cut the masking tape and remove the glass.

Step 6. Clean and prepare the glass. Clean the existing glass with clean water and a lint-free cloth. For new glass, clean glass with glass cleaner and a clean cloth. Close cut the urethane if it is in good condition to a thickness of 1– 2 mm. Clean with water and a clean cloth.

Step 7. Prepare the undamaged pinchweld. Close-cut the old urethane down to a thickness of 1– 2mm. Clean the pinchweld area with water and a clean cloth.

Step 8. If necessary, apply primer to the pinchweld. Again, check the expiration date on the primer, and shake the primer well.

For the undamaged pinchweld area, apply the primer to any bare metal scratches (if necessary).

For the damaged pinchweld area that has been repaired, apply a continuous layer of primer to the newly abraded and cleaned epoxy primer. Allow 5 –10 minutes of dry time for the primer.

Step 9. Apply the urethane and install the glass. Check the expiration date on the urethane. In most cases, you'll need to cut the application nozzle to the desired width and shape, and then install the flex pack into the applicator gun.

Apply urethane to either the close-cut urethane on the undamaged pinchweld area and/or the prepped epoxy primed area of the new pinchweld. Paddle all gaps in the urethane in one direction and install the glass.

Step 10. Reinstall the moldings and panels. As necessary, reinstall the moldings and interior panels and reconnect any electronics.

Also, remove excess urethane and keep vehicle out of service until the urethane builds strength, according to manufacturer recommendations.

(Photo courtesy of Auto Glass Cheyenne) Note the broken glass surrounding the repair area. All of this glass will need removed and the area will require surface protection during the repair.

Replacing moveable glass
Replacing movable glass is the one type of glass repair shops engage in most frequently. Movable windows are often damaged in collisions and replacing them doesn't involved adhesives or safety issues that can convince repairers to send this work elsewhere.

The greatest challenge with this work typically involves the sometimes complex steps needed to disassemble/reassemble the door and the mechanism that raises and lowers the window. Of course, you'll want to stick to the OEM repair instructions, but replacing movable glass involves 8 basic steps.

Step 1. Disassemble the door panel. This usually includes removing the panel, along with the armrests, door handles and other attachments.  

Step 2. Set window-height-regulator mechanism to its service position. This is the point where the screws or bolts holding the glass to the regulator align with access holes stamped in the steel. If necessary, disconnect the electric connections.

Step 3. Remove the old glass. Be sure to use gloves, especially if the window is broken or cracked. Pick out any remaining glass and thoroughly vacuum the area.

Step 4. Install the guide. Many vehicles require a plastic piece to be inserted into a small hole on the rear edge of the replacement window. The plastic guide keeps the window in the track. On some vehicle models, the guide can be inserted after the glass is placed into the window track.

Step 5. Place the glass into the track. Most windows should slide easily into the track. If your doesn't, try  dropping the "short" end of the glass first, at a 90 degree angle. Rotate the short side until the glass fits into the track.

Step 6. Reconnect the electric connections. Test the operation of the window to ensure it moves up and down smoothly.

Step 7. Reassemble the door. Replace the door panel from the top down.  Reconnect any items that were disconnected from the door panel when it was removed.

Final thoughts

Along with obtaining some new tools, shops interested in joining the glass market will need to make some other investments. Training is necessary, as is certification and licensing for windshield repair and replacement. Shops also must decide who it will train for this new work and how it will be incorporated into finely tuned operational schedules. From there, they need to determine if the investment will produce significant rewards.

In some cases, it may not. Because many glass repairers offer mobile services, these shops can continue having this work performed on site, though the profits will go into someone else's pockets. Repairers need to decide if this extra revenue would fit much better into theirs.

(Photo courtesy of Intermountain Auto Glass) New, quick-drying adhesives make glass replacement more convenient than ever.

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