TIL most people are cleaning flux off PCBs way too aggressive with isopropyl

I was fixing a 1980s Marantz receiver last month and the previous "repair" had scrubbed the board so hard with a brush they ripped off 3 traces. Flux isnt evil. If its the non corrosive no clean kind just leave it alone. I learned this the hard way after ruining a perfectly good Pioneer amp in 2019 by overcleaning. Now I only use a little 91% alcohol on a Q tip for specific spots. Who else has seen boards wrecked by overzealous cleaning?

2 comments

2 Comments

the_karen1mo ago

Ripped off 3 traces" sounds like they were going for a speed record, not a repair.

cora_scott771mo ago

Ask them straight up: what kind of brush were they using on that Marantz board? I've seen guys use stiff nylon brushes like they're scrubbing a dirty pan, and that's a recipe for ripped traces. If you're not using something soft like a horsehair or ESD safe brush, you're asking for trouble.