Interesting point about the canopy, though I'm not entirely convinced it's practical for every situation. I've found that even with shade, humidity can still wreak havoc on weld consistency. Have you considered adjusting the welding speed or temperature settings slightly during peak heat? I've experimented a bit and noticed minor tweaks sometimes offset the gummy texture issueβthough admittedly, results can vary quite a bit depending on the specific TPO brand and thickness...
Good call on adjusting the welding speed and temp. I've noticed the same thingβsometimes just dropping the temp 10-15 degrees or speeding up a touch helps keep things from getting gummy when it's blazing out. Another trick that's worked for me is welding earlier in the morning whenever possible, before the humidity really kicks in. It's not always doable, but it can save a lot of headaches on tricky TPO brands. Also, cleaning the nozzle tip more frequently seems to help too...keeps the airflow consistent.
I've been messing around with my own TPO roof lately, and honestly, I'm still getting the hang of dialing in the temp. Dropping it by 10-15 degrees sounds reasonable, but how do you guys actually tell when it's just right? I've tried the morning welding trick too, but sometimes even then it feels like I'm guessing. Maybe I'm overthinking it, but is there a specific sign or feel you're looking for to know you're in the sweet spot?