What do you use to clean off excess flux from your projects?

[vanessa]

I've been using denatured alcohol and it just pushes the flux around. I use a small brush and it takes several passes, then it's still sticky. I've tried some acetone after the alcohol process and it helps a little but there has to be something better. Is there?

:roll:

[Jason Stout]

I use a toothbrush and "electrical contact cleaner." It works well for me, but you can buy flux remover as well.l

[Paul Marossy]

Those bottles of alcohol that I never use in those RadioShack PCB kits work for removing excess flux. It does take a few passes, though. It depends on how much excess flux there is.

EDIT: I forgot to mention that I also use a Q-Tip.

[Mark Hammer]

I use alchohol also, only I tend to apply it to a confined area with a Q-tip.  One end spreads the alchohol and rubs the flux into a softer state.  The other is used to absorb the excess liquid and flux and dry the board off.  It *does* stay a little tacky, but it least you can see which traces are and aren't joined.

[mojotron]

I quickly break the flux up with a small wire brush, run an xacto knife between close contacts - just to make sure that there is no contact. Then I use alchohol as well, a non-diluted kind I found at walmart -  and the small wire brush. I can get really aggressive with the brush and it does a fair job.

I'm sure there is a better way to do this, but I learned this way a long time ago and have always done this as part of my final board checkout - where I look for bad solder joints.

[Tubebass]

I use 99% isopropyl alcohol in a squirt bottle and a toothbrush. After scrubbing the flux off with alcohol and toothbrush, flood the board with alcohol to wash off the residue. Tilt the board so the alky can run off into a rag or paper towel.
 What works even better is lacquer thinner. It's nasty stuff though, so use it outdoors or with VERY good ventilation.

[Fp-www.Tonepad.com]

I used to do the alcohol-toothbrush-qtip-running water, but now I just leave the flux alone. In my experience it doesn't do anything bad to the board, so I find it a lot easier to just leave it there.

Fp

[moogatroid2000]

Use a solder that uses water soluble flux.

[Pushtone]

Use a solder that uses water soluble flux.

Yeah, I was going to add this too. I think the solder I got is called "organic" core solder (as opposed to rosin core). It's flux washes off with warm water.

[moeburn]

....clean......flux.....?

[Connoisseur of Distortion]

why should we get rid of it? does it have the etching power to damage the board?

[moeburn]

why should we get rid of it? does it have the etching power to damage the board?

Only YOU have the etching POWER!

[aremesnik]

I have never tried it. but in college my professor told us that Jose Quarvo Gold worked fairly well.

[Satch12879]

I have never tried it. but in college my professor told us that Jose Quarvo Gold worked fairly well.

Good thing it wasn't a Mexican culture class.

It's "Jose Cuervo"

There's always FLUX CLEANER...

[KORGULL]

I have only cleaned some of my boards. I'm assuming that as long as the circuit checks out alright at the initial firing up and testing that the flux is fine where it is...or does it sometimes heat up and reflow - possibly causing problems later?
So far the only problem has been with a new, store-bought DS-1 that had a volume control that worked exactly like the tone control. The board was very dirty. Along with some flux residue, it looked like it had been splashed with something. After a good cleaning with alcohol on a Q-tip and a rag the pedal worked fine.

[aaronkessman]

er, i always thought flux was corrosive? at least mine turns my copper traces an icky, gooey, sticky green when left on for too long. i would definitely clean off excess, maybe not of solder or the board, or even wires, but definitely off copper pcb.

[moeburn]

Maybe i'm using the wrong ($2) solder, but I don't see any reason to clean any flux off.  All I get is a little clear smear sometimes like varnish, but thats it.

[vanessa]

Maybe i'm using the wrong ($2) solder, but I don't see any reason to clean any flux off.  All I get is a little clear smear sometimes like varnish, but thats it.

There are times, and they are few that I have found that excess flux will cause a bridge between circuit points. This can cause a short in the circuit. I can sometimes see after a project is complete if there are typical issues with it that it might be as a result of excess flux. Time and time again by cleaning it off good with a solvent it resolves these issues.
.

[Paul Marossy]

There are times, and they are few that I have found that excess flux will cause a bridge between circuit points. This can cause a short in the circuit.

I have had this experience once, but no one seemed to believe me.  :?

[Pushtone]

There are times, and they are few that I have found that excess flux will cause a bridge between circuit points. This can cause a short in the circuit.

I have had this experience once, but no one seemed to believe me.  :?

The tech who directed me to the water based flux solder claims that he improved the sound quality of and fixed intermitent problems with Hafler power amplifiers by only cleaning off the flux which Hafler left on.

Things are much more critical in high voltage power amplifier so problem come out sooner I guess. This techs creed is "wash it off" even on low voltage PCBs.

That bit about copper traces turning to sticky gooy mess is going to keep me from sleeping as I think about the first few pedals I built with rosin core solder.  :cry: