A seamless welding solution

By Emma Peterson.

Learn how Leister’s new innovations and technology prevent long-term roofing issues.

For over seven decades, Leister has been consistently developing and improving technology and tools used in plastic welding and industrial hot-air applications. In one of The Coffee Shops™ Read Listen Watch® (RLW) webinars, Heidi J. Ellsworth got to talk to Dave Nordentoft and Brittany Wykle of Leister about some of the newest products and tools they have been working on in 2025.

One of the big topics they spoke about was the improvements that have been made to the VARIMAT system. The original VARIMAT came out in the late 1990s. Since then, the Leister team has consistently worked to improve the system. Dave explained, “We try to gain feedback from the field, from those that use our machines, from those that work with it, those that distribute, those that repair it, and ask, ‘What can we do better?’ Once we get that feedback, we try to incorporate that into the next generation.”

Now on generation four, the Leister team has implemented a variety of improvements on the VARIMAT. When talking about it, Dave specifically highlighted the upgrades done to the Leister Quality System (LQS). He shared, “LQS was introduced into the roofing category about two years ago. What it does is record the welding data in the background on the machine. So every time the nozzle is inserted, the temperature, the speed, the airflow, the incoming voltage is all being recorded for every seam. At the same time, the GPS coordinates of that seam are being recorded.”  

Tracking all of this means that, from a computer, phone or tablet, you can look at the recorded data of the machine and analyze the welds as you are working. Dave elaborated, “Of course what we're looking for are nice, flat, straight, consistent lines, no changes, no deviations. So, for each seam, you can look for anomalies or things that change.” This allows you to catch any inconsistencies right away. Then you can go back to those spots and investigate further, with tools like Leister’s new vacuum plate. Brittany explained how simple this product is to use, saying, “Let's say you did some flashing work on some curbs. You want to check to make sure everything is watertight. You could just use the vacuum plate. As long as there are no bubbles, then you know that you're good.”

By giving crews the opportunity to recognize and resolve any issues right away, Leister is helping avoid costly repairs for issues like leaks down the line.  

Read the transcript, Listen to the episode or Watch the full RLW for more about Leister and how their innovations are improving how contractors work on the roof.