When repairing circuitry, its often tricky to remove flux residues from the PCB after rework. The flux remover spray I find locally in my area doesnt seem to be very effective.
From what I understand years ago, they banned the really good stuff
for this (some type of CFC). Can anyone recommend an effective flux- remover spray (brand) that perhaps I can order online? Thanks
A trick I used to do when I repaired boards for a commercial company, was to lightly brush over the newly soldered joints with a brass wire brush, then mop over the area with isopropanol. This smooths out the coating on the board and makes it virtually impossible to see which components have been changed.
Ron(UK)
I've never bothered in many many years of DIY building stuff and never had problems. Might make a difference with densely packed SM technology, though.
Why not use the watered down stuff? Some of the fluxes out there are water soluble and between the alcohol and the water I think you would have the bases covered. We have been using 90% for 20+ years. Seems to have worked just fine for us. In fact, until they changed their formula, we used a local industrial chemical manufacturer's "Window Cleaner" that was just isopropyl, water, some surfactants, and a little blue dye. 55 gallons drums of the stuff was pretty reasonable.
Jim
For many years I've used Servisol De-Flux 160. Just got a new can today in fact. Cheap, well behaved and controlled aerosol, and very effective.
Arfa
James Beck wrote in news: snipped-for-privacy@newsgroups.bellsouth.net:
The usual "rubbing" alcohol found in US drugstores is 70% alk.
Here, I have no problem finding 90% at our local national chain drug store.
70% is the most common, but 90% is not that obscure.Jim
Dave Plowman (News) wrote:
This violates the teachings of every advisor I have ever had.
Makes me think you don't live near a large body of water. When working in a Southern climate near the Atlantic Ocean, airborne moisture was the enemy. Anything that would absorb it was equally depricated.
This report
In the UK? You're never that far from a large body of water. Including the sky...
If the sort of flux found in standard lead multicore solder was very hydroscopic surely it would be easy to wash off with water?
I'm ignoring modern lead free solder and water based flux. For the rest of my life. ;-)
Rosin-based flux comes in several levels of activity. Type R (rosin) flux contains rosin only, with no cleaning agents. RMA flux (rosin-mildly activated) contains a nominal amount of cleaning agents, and RA (rosin-activated) flux contains a fair amount of cleaning agents. The cleaning agents act on the metals being soldered to remove surface contaminants and float them away so the metals are adequately wetted by the solder. The RMA and RA fluxes are corrosive if insufficient heat is applied to the fluxed area during solder to neutralize the cleaning agents, and over time will definitely cause problems if not properly cleaned after soldering.
Water soluble fluxes are more active than any of the rosin-based fluxes. Organic flux is more active than RA flux and inorganic flux is the most active. Obviously, all fluxes need to be cleaned after soldering to avoid any possibility of contamination or corrosion. Mil-spec soldering requires that all flux residue be removed after soldering is complete.
I've never noticed being given a choice when buying lead multicore. And I buy it from a large supplier, and keep four reels of different sizes on a dispenser. Perhaps I've simply never looked. Of course what industry uses for mass production can well be different from that used for one off construction, repair and servicing.
The earliest PCB I have and assembled is well over 40 years old. Still works fine. ;-)
I use ethanol when I get it for free. You can even take a drink if you need it.
95% is the common variety, and the higher % stuff has some nasties.Electronic supply houses sell the isopropal, allthough shipping can be a problem fo rthe high % stuff. I have also used some harsh spray cleaners, but they can damage components.
We used to use Tri back in the 60's to clean boards. used to have a spigot at DEC for cleaning boards. Worked the best.
greg
I use laquer thinner on a q-tip. Wrks well for me. It does leave a slight whit residue sometimes, but that is easy to wipe off.
- Tim -
Acetone and a small brush works nicely.
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I use MEK (methyl ethyl ketone). I can pick it up in gallon sized cans at a paint store. Does a wonderful job with flux, just don't get it on plastic...
Mark Z.
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