You can also find 99% isopropyl if you look around, at least in the US. Amazon carries it as well.
toggle quoted message
Show quoted text
On Sep 2, 2019, at 20:58, Wayne <wb6bfn@...> wrote:
Reginald has an excellent point about residue removal. 91% isopropyl alcohol works well as does acetone if done quickly. Just be sure to remove any left over residue, usually a white powdery stuff. In aerospace and military applications we spray the cleaned boards with polyurethane but that's very hard to remove for repairs. I've found that Krylon crystal clear works just as well as a moisture barrier, is not gyroscopic and is easily removed with a hot soldering iron (don't breath the fumes).
Never leave anything that absorbs water on a sensitive electronics circuit board!
?Wayne Maynard <wb6bfn@...>?
On Sep 2, 2019, 20:28, at 20:28, "Reginald Beardsley via Groups.Io" <pulaskite@...> wrote:
I replaced both SMA connectors with bulkhead units soldered on both
sides of the PCB and while cleaning up was reminded of an important
detail.
The OEM did not clean the flux residue after soldering the SMA
connectors. If you want a stable unit, clean it off with isopropyl and
an old toothbrush. Otherwise you will have time and humidity varying
parasitics. I dry things with a hair dryer on low after cleaning using
91% isopropyl to get rid of the water residue. If you see residue of
*any* kind, rinse it again, blot with a towel and dry. I do *not*
leave any residue behind.
I've repaired a bunch of consumer gear and a 34401A just by cleaning up
the flux residue.
Have Fun!
Reg
