Tried hot air rework on a corroded laptop board and it backfired badly

Ngl, I thought hot air would be faster than scrubbing with alcohol on a corroded HP laptop I got from a pawn shop in Austin. I set it to 350C and blasted the corrosion near the charging IC, but the flux and junk just melted deeper into the board and shorted three traces. Learned the hard way that patience with a fiberglass pen and isopropyl beats heat every time for corrosion. Has anyone else found hot air making corrosion worse instead of better?

3 comments

3 Comments

flores.emma12d ago

Gotta disagree with you here. 350C is way too hot for corroded boards, that's basically torching it. I've had way better luck using low heat around 200C to just soften the gunk, then hit it with compressed air to blow the melted flux and corrosion away before it soaks in. The fiberglass pen is solid for heavy stuff, but for light surface corrosion hot air at the right temp beats scrubbing every time if you keep the nozzle moving. Sounds like your technique just needs a tweak, not the tool itself.

jason_stone5912d ago

I get what you're saying @flores.emma but I think 350C with a small nozzle actually works fine if you're moving fast. @danielr99 mentioned green crusty pins on vintage boards and honestly that stuff laughs at 200C, I've had to crank it up to get it to release without scraping. I can see your point about blown traces but I've ruined more pads scrubbing with a pen than I ever have with controlled hot air.

danielr9912d ago

Oh man, have you tried this with really old boards that have that green crusty stuff all over the pins? I had a vintage audio board that looked like it was growing its own ecosystem and low heat at 200C with compressed air was honestly a lifesaver. @flores.emma is totally right about the temp thing, I cooked a board once at 350C thinking I was being careful and ended up peeling a trace right off the pad. The trick with the compressed air after softening it up just blows all that nasty junk away before it gets a chance to soak into the board fibers. Plus you get that satisfying puff of smoke that makes you feel like a wizard or something haha. I still keep a fiberglass pen for the really stubborn spots but for light corrosion this method is way less aggressive on the board itself.