Took me 5 years to figure out I was cleaning flux wrong

I used to scrub boards with isopropyl alcohol and a toothbrush then blow them dry. One day I repaired a vintage receiver from 1978 and the owner said the board looked "foggy". That's when I learned you need to use deionized water first then alcohol to get all the residue off. Now I do a 3 step wash and haven't had a single cold solder joint since. Anyone else find out they were skipping a basic step for way too long?

4 comments

4 Comments

the_elizabeth1mo ago

Man, that foggy board thing would drive me nuts. I used to be one of those "just alcohol and elbow grease is fine" people, honestly thought the extra steps were overkill for hobby stuff. But after reading a repair blog a couple years back I gave the deionized water first method a shot on a crusty old amp and it was night and day. The residue that came off in that second alcohol pass was ridiculous, never going back to the shortcut now.

lisab321mo ago

Does the type of solder make a difference with that method?

logan_anderson401mo ago

Agree with @the_elizabeth, I used rosin core and it worked fine after that water soak.

anthony_jackson319d ago

Tried that same method on an old Fender twin reverb that had years of gunk built up. The water soak loosened all that crusty flux and the alcohol wipe after was crystal clear. Made a huge difference in how clean the board looked and probably saved me some future headaches.