Interesting points, especially about wind chill—never really thought about it much myself. But honestly, I'm not totally sold on the idea that cooler mornings always mean you need higher heat. When I was patching up my garage roof last fall (first time dealing with TPO, mind you), I actually found that cranking up the heat too much early in the morning made things worse. The membrane softened quicker than expected and ended up warping a bit.
Maybe it's just me being inexperienced or something, but I found that going slow and steady at a moderate heat worked better, even when it was chilly out. Trial welds definitely helped though... learned real quick to dial things back after messing up a couple test strips.
Guess what I'm saying is—ambient temps matter for sure, but sometimes less adjustment is needed than you'd think. Just my two cents from limited experience...
You're definitely onto something with the moderate heat approach. TPO can be a bit finicky, especially when you're still getting a feel for it. I've seen plenty of folks crank the heat way up thinking it'll compensate for cooler mornings, only to end up with warped seams or even burn-throughs. Your trial-and-error method with test strips is spot-on—it's really the best way to dial in your settings. Sounds like you're already getting a good handle on it... keep trusting your instincts!
"I've seen plenty of folks crank the heat way up thinking it'll compensate for cooler mornings, only to end up with warped seams or even burn-throughs."
Exactly. I've noticed that ambient temperature isn't the only factor—wind speed and humidity play a surprisingly big role too. Even if your heat setting worked perfectly yesterday, a gusty morning can throw everything off. Personally, I prefer starting slightly lower and adjusting upward gradually. It might slow things down initially, but it saves headaches later when you're not patching burn-throughs or redoing seams...
Totally agree with you guys on this. I've seen some pretty experienced welders get caught off guard by a sudden breeze or a damp morning. Funny thing is, I had one guy swear up and down that his settings were perfect—until he realized he'd parked his truck right next to the seam he was working on, creating a weird wind tunnel effect. Took him half the morning to figure out why his seams kept looking like melted cheese sandwiches.
Another thing I've noticed is that nozzle distance can make or break your welds, especially when conditions are iffy. Even if your heat's dialed in just right, holding the gun too close or too far can mess things up pretty quickly. I usually tell my crew it's like grilling burgers—too close and you're burning dinner, too far and you're eating raw meat. Gotta find that sweet spot.
Anyway, starting lower and easing into it definitely saves headaches later on. Better to spend an extra 20 minutes tweaking settings than two hours patching holes and explaining to the boss why we're behind schedule again...
Yeah, nozzle distance is key, but honestly, I've seen guys obsess over heat settings way too much. Conditions change constantly—humidity, wind, even the membrane brand matters. Best bet is to test a scrap piece first... saves a ton of headaches later.
