I've been cleaning flux wrong for years and didn't know it

I used to just wipe leftover flux off boards with isopropyl and a rag, thinking that was good enough. Then I brought a repair into a shop in Portland and the guy there asked if I was leaving white residue on purpose. He showed me under a microscope how the flux was still active and eating at traces over time. Now I use a ultrasonic cleaner with hot water and it takes like 10 minutes for a whole board. Anyone else get caught using the lazy method for way too long?

2 comments

Log in to join the discussion

Log In

2 Comments

harperwright3mo ago

Gonna have to disagree a little here. Plenty of people, including some old school techs I know, use isopropyl and a rag just fine without issues as long as you actually scrub the board clean and let it dry fully. White residue usually means the flux didn't fully dissolve or the alcohol wasn't pure enough, not that it's automatically eating traces. A ultrasonic cleaner is nice but calling isopropyl lazy feels like a stretch when it works for 90% of basic repairs.

8

brookep623mo ago

Hang on @harperwright, you're actually saying you've seen people scrub boards with isopropyl and a rag and it turned out fine? I'm genuinely shook, I thought that was basically a guaranteed way to mess something up.

4