After assembling a board and cleaning the flux residue off with 99% alcohol and a stiff brush, there is residue remaining on the board. I tried “rinsing” with CRC electronics cleaner, but they left white residue behind. What can I use to cleanly rinse this off the board? Trying to wipe with a cloth gets caught on all the little solder nubs.
Commercially boards are soldered with aqueous based flux, cleaned with hot water and dried. Most components are made to handle it. Solvent based flux removers were phased out by the EPA long ago.
After the cleaning and brushing, I blow the dirty solution off the board (and brush) with compressed air, then spray more IPA on the board, and blow the board dry again. Repeat if necessary.
This is a bit harder to accomplish if you don't have access to an air compressor. "Canned air" doesn't go very far. You might get away with doing this at a gas station after hours. I'd try adding a nozzle to an old bike tire valve stem. Or use the gas station air to fill a portable tank; there are kits to turn old propane tanks into air tanks. That much air won't go far, but it would let you do the board cleaning in a nearby vacant lot rather than the gas station forecourt.
Come to think of it, though, I've gotten boards clean enough just by whipping/shaking off the dirty alcohol, though I think it took more rinsing, and I may have sacrificed some precious canned air after the final rinse.
This is a bit harder to accomplish if you don't have access to an air compressor. "Canned air" doesn't go very far. You might get away with doing this at a gas station after hours. I'd try adding a nozzle to an old bike tire valve stem. Or use the gas station air to fill a portable tank; there are kits to turn old propane tanks into air tanks. That much air won't go far, but it would let you do the board cleaning in a nearby vacant lot rather than the gas station forecourt.
Come to think of it, though, I've gotten boards clean enough just by whipping/shaking off the dirty alcohol, though I think it took more rinsing, and I may have sacrificed some precious canned air after the final rinse.
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