by Bob Beranek

We have often talked about how the windshield and other auto glass parts contribute to the safety of the vehicle occupants. However, did you know that the glass parts in an automobile are instrumental in the fuel efficiency as well?

Obviously, safety is a major concern to all who make, sell, buy and service a vehicle, but fuel savings are also a concern to automakers, owners and climate change advocates. The Obama administration put a mandate upon vehicle manufacturers to reach a Corporate Average Fuel Economy (CAFE) standard of 54.5 mpg average on their vehicles by 2026. The current administration has proposed to change that directive because it felt the requirement was unattainable. Until the Safer Affordable Fuel Efficient (SAFE) Standards are voted on, the Obama CAFÉ standards are still in play. Carmakers are looking to glass manufacturers to make discoveries that reduce weight and drag.

What does this mean to the auto glass industry?

There are a couple of reasons why glass is important to carmakers when it comes to fuel efficiency.

Photo courtesy of Elektrek

  1. Glass is smoother than painted steel so if more glass is used in manufacture, the less drag there is, and more miles can be driven on a gallon of gas. Therefore, you see so many vehicles with panoramic roofs, new headlight systems, and drastic curves in the glass like the Tesla X.
  2. The exposed-edge windshield mountings also contribute. The fewer mouldings there are around the windshield, the better the drag coefficient a vehicle has. The less drag, the more miles are squeezed from a gallon of gas.
  3. Gorilla glass is lighter weight than normal annealed glass, so Corning decided to introduce themselves into the auto glass market. The same goes for thinner windshield construction. Honda introduced asymmetrical glass a few years ago. They figured that if they could put thinner glass on the inside surface of the windshield and keep the outer glass the same, they could reduce the weight by 25%. Less weight equals more fuel efficiency.
  4. The Advanced Driver Assistance System (ADAS) is not only a safety system, it also contributes to fuel efficiency as well. Adaptive cruise control sets a speed and the vehicle sticks by it without a lead-footed driver accelerating and braking erratically.

Glass is primarily made of sand, a material that is plentiful and inexpensive to obtain. If carmakers are concerned about the price of their product and the need to meet CAFÉ standards, they will use glass to reduce costs and provide safety and performance. We will be there to put it in.

Is the old cold knife disappearing? Will the wire/cord crimping tool overtake other auto glass removal tools? Are violent power removal tools going to be replaced with more passive tools?

Recently I thought about who invented the cold knife and when it was first offered? It certainly had a good run. When I started in the industry, in the mid-70s, the cold knife was a major tool in my toolbox along with a hook tool and a utility knife. Wire and handles were also present, but the cold knife took the lead when it came to glued-in glass removal tools.

I figured the cold knife would be easy to research, so I began probing. There was no shortage of sites offering “auto glass removal tools” for sale, but the history of the tool was seriously lacking. The many names associated to the tool over the years caused a major problem. Cold knife, cable knife, windshield removal tool were all used interchangeably, which makes it difficult to track down.

The first cold knife

I called my friend and colleague, Bob Nilsson from Ultra Wiz who steered me to Jeff Cothery. Jeff told me that his father, Harry R Cothery, invented the cold knife based on PPG’s suggestion in the early 1960’s. He went on to invent and patent the “Hot Knife” as well, patent number 3,448,517. Unfortunately the hot knife never really took off like the cold knife did, and due to the existence of similar tools, it was unable to be patented. Jeff turned out to be a wealth of information and I want to thank him for satisfying my curiosity.

The first hot knife

Now to address the questions above.

Is the cold knife disappearing? I believe current technicians will never let it disappear completely. The cold knife took them a while to master and once they did there was never a tool that could remove the glass faster and smoother than a well sharpened cold knife.

Will the wire/cord crimping tool overcome other auto glass removal tools? With the potential for vehicle damage minimized, no physical exertion required, and providing even an inexperienced tech the ability for a safe efficient removal, they provide a lot of benefits. As people get used to seeing wire-out tools and trying them, they will increase in popularity.

Will the power removal tools be replaced with more passive removal tools? I don’t think so. Power tools are the fix when all else fails. If power tools are used incorrectly they can cause serious damage to the vehicle, but for experience techs there will always be a place in the tool box for the ultimate tool that will “get-er done”.

You have to say a few things about Harry’s cold knife invention, the long learning curve it takes to master and the effort expended using it, the cold knife, when used properly still works great. Don’t throw your cold knife away yet.

The fall season is here, and there are a few things you may need to adjust to compensate for the colder weather.

  • Clothing – Colder weather means proper clothing should be acquired for comfort and quality installations. A cold technician hurries through their installations and can cut corners. You should dress in layers, so when the day wears on and temperatures rise a layer of clothing can come off.

    Photo courtesy of

    Photo courtesy of

  • Scheduling – It’s great to do installations in the open air during the summer and spring. However, the cold winds of the fall and winter are not as pleasant. Make sure to schedule jobs with shelter available as often as possible because cold winds and wet weather are not conducive to proper installations.
  • Tools – You might be able to get by with dull blades and cold knives in the summertime but fall brings stiffer and harder to cut urethane beads. Make sure your blades are sharpened in the morning and honed up during the day and that your power tools are in good working order.
  • Parts – Cooler weather brings more brittle plastic parts. Make sure your parts box is stocked and inventoried. Also you should have your heat gun and hair dryer at the ready to warm up vinyl and dry out pinchwelds. The sun is not as warm in the fall so be prepared to smooth out that “washboard” moulding before you leave each job.
  • Adhesives – Sealants and adhesives will be stiffer in colder temps. Keep them warm by taking them in the shop at night. During the day you can keep them warm by exposing them to warmer air blowing from the floor heaters. I do not recommend using your defrosters on the dashboard, as that can make those cartridges or packages flying projectiles in case of an accident. Check with your adhesive manufacturers’ instructions so you will know what you can and cannot do when storing your chemicals.
  • Primers – Most primers have a longer drying time in colder weather. Make sure you check the proper timing and adjust your installation procedures to compensate.
  • ADAS – Many Advanced Driver Assist Systems (ADAS) turn themselves off when the cameras and sensors cannot see the road markings due to rain or snow. You should be aware of this and make sure your customer knows recalibration is required even though the system has shut itself down.
  • MDAT – The Minimum Drive Away Times (MDAT) may have to be adjusted to compensate for cooler and dryer temperature. Some adhesive systems do not need any adjustments except for some primer dry times, however others do need to be adjusted according to the heat and humidity of the day. Keep you MDAT charts available for reference.