"Better to periodically test welds on scrap pieces first—just takes a minute and saves headaches later."
Couldn't agree more. Learned this the hard way a few years back when I trusted the smell test alone. Thought everything was fine until we got a callback after heavy rain—had to redo half a day's work. Now I always keep scrap TPO handy for quick peel tests. Takes barely any extra time, and it's saved me from plenty of headaches since then...
Couldn't agree more. Learned this the hard way a few years back when I trusted the smell test alone.
Periodic scrap tests are definitely helpful, but relying solely on peel tests can sometimes be misleading. I've noticed that peel tests might pass even if the weld is slightly overheated, which can degrade the membrane long-term. A better practice might be combining peel tests with visual inspections—checking for subtle discoloration or glossiness changes around the weld area. This approach has helped me catch overheating issues early, before they become a real headache down the line...
Yeah, peel tests alone can definitely trick you sometimes. I've had welds look perfect at first glance—passed the peel test no problem—but then a few months later, you start noticing tiny cracks or brittleness around the edges. I started paying closer attention to the sound of the welder and how smoothly it moves across the membrane. If it drags or feels sticky, that's usually a sign it's running too hot... saved me from plenty of headaches lately.
I've noticed something similar with TPO welds myself. Peel tests are useful, but they're definitely not foolproof indicators of weld quality. Sometimes even a weld that seems solid initially can degrade over time, especially if the membrane got overheated during installation. Like you said, that drag or stickiness when you're welding is usually a good sign things are running too hot.
One thing I've found helpful is checking the actual temperature of the air coming from the tip of the welder with an infrared thermometer every now and then—especially if I'm working on a larger area or it's a particularly hot day. Manufacturer specs typically recommend somewhere around 950°F to 1000°F (510°C to 540°C), depending on the brand and thickness of the membrane. But ambient conditions like wind, humidity, and even the color of the membrane can affect how much heat you actually need.
I've also learned to watch for subtle discoloration or glossiness around the edges of the weld bead. If it looks shiny or overly glossy, that usually means the membrane's surface has been overheated, potentially weakening the weld over the long run. It's a subtle clue but can save you from issues months down the road.
I'm curious though—have any of you experimented with adjusting your welding speed rather than just temperature? I find that sometimes slowing down a bit helps me keep the temperature consistent without overheating the membrane, but I haven't really nailed down a definitive rule of thumb for that yet. Would love to hear if anyone else has experience with that approach.
I've actually found that slowing down too much can sometimes cause more overheating issues, especially on hotter days. Instead, I prefer slightly lowering the temp and keeping a steady pace—seems to give me more consistent welds overall. Might just be personal preference though...
