I was fixing a laptop in my shop and realized I've been using the wrong kind of alcohol for years

So I was cleaning a really old motherboard yesterday, one from a 2012 MacBook Pro that was covered in gunk. I grabbed my usual bottle of 70% isopropyl alcohol without thinking and started scrubbing. My new helper, a kid named Jake, just watched for a minute and then said, 'My teacher at the tech college said 70% leaves water behind and can cause corrosion on old boards.' I froze, because he was right. I'd always just used what was cheap and easy to find at the drugstore. I switched to 99% for the rest of the job and the board dried so much faster and cleaner. It's one of those things you do for so long you never question it. Has anyone else had a 'duh' moment like that with a basic tool or cleaner?

2 comments

2 Comments

thomas_roberts1mo ago

Yeah, I read that the water in 70% can mess with old circuits.

sagesingh1mo ago

Wait, you were using 70% on old boards for years? That's wild (and honestly a little scary). I can't believe you never had a single board come back with weird corrosion issues after a clean.