how hot is too hot when welding TPO roofing?

Had a similar issue myself a while back - thought I had the temp dialed in perfectly, then suddenly the seam just went gummy on me. Turns out ambient temp and sun exposure can really mess with your settings. Were you welding in direct sunlight or shade? I've noticed even decent TPO can get finicky depending on weather conditions...

Had the same exact thing happen to me last summer - thought I had the sweet spot, but a little cloud cover rolled in and boom... gummy seams. Definitely frustrating, but you're on the right track by paying attention to weather. Just keep tweaking and you'll get a feel for it.

- Cloud cover can mess with temps, sure, but honestly, ambient temp isn't always the main culprit.
- I've welded TPO in blazing sun and cloudy days alike - it's more about gun speed and consistent pressure.
- If your seams are gummy, try dialing back your heat slightly and slowing down your pace a bit.
- Weather matters, but technique usually matters more.

Had a crew out last summer welding TPO on a rooftop that felt like an oven - temps pushing 95 easy. They struggled at first, seams got gummy fast. Adjusted their speed and heat settings, and things improved. Curious though, anyone notice certain TPO brands handle heat differently?

"Curious though, anyone notice certain TPO brands handle heat differently?"

Interesting point about brands, but could it also be batch variations rather than strictly brand differences? I've seen crews struggle with the same brand on different jobs - one week smooth sailing, the next gummy seams everywhere. Maybe storage conditions or age of the material plays a bigger role than we realize...? Just thinking aloud here, but has anyone else noticed inconsistencies even within the same brand?