How do you remove flux residue after soldering?

[777funk]

I'm changing out some SOIC surface mount opamps on a I/O for my recording setup. I'm having a problem with a mess of flux surrounding everything I unsoldered installed the new part and resoldered. How do I remove the flux?

I've heard flux residue can cause hiss in low signal sections of amps. I do not want hiss.

Forgive me if this is a dumb quesiton. I honestly haven't found any good/safe way to remove flux residue.

thanks!
Nick

 

[Zero Cool]

I use a small screw driver and carefully chip away the large deposits the best i can. then use a brush to wipe them away. then i use Alcohol and a q-tip to remove the rest of the residue. or sometimes a toothbrush to scrub it away. works well.

 

[Cal Weldon]

If you have used alcohol and a toothbrush and the residue remains you may need to use an ultrasonic bath. (usually not necessary)

EDIT: Missed Zero Cool's post.

 

[grjr]

I like to use acetone (nail polish remover) because it is a lot faster at dissolving flux than alcohol

 

[Cal Weldon]

Acetone will work faster but leaves a residue itself. I guess one could then wipe with alcohol if needed.

 

[Sam Lord]

Try Everclear (95% ethanol solution). Danger, highly flammable, store safely, use with great caution. Use a needle dropper to apply. Works great, nontoxic when inhaled up to a point.

 

[nikwal]

We've always used acetone at work(real acetone not nail polish remover with oil). and a couple of theese http://www.rolexreferencepage.com/articles/qtip.jpg made of wood..
You can use a plastic esd safe stick to remove hard residue. and if you want to use a brush, make sure its not dry.
Or you could have used another type of solder with another type of flux, and the problem would'nt be as big

 

[mjf]

hello.
i used ipa cleaner (isopropanol) and a stiff brush........
greetings.............

 

[MJL21193]

Lacquer thinner and toothbrush. Ultra effective.

A need to be careful with it though - it's poison and flammable, but so is isopropyl alcohol.

 

[tsmith1315]

Try Everclear (95% ethanol solution).
...
Works great, nontoxic when inhaled up to a point.

Also works great for ingestion, and nontoxic up to a point for that as well.

 

[Cal Weldon]

 

[777funk]

I build guitars so I have LOTS of lacquer thinner around. After seeing the acetone post I tried lacquer thinner and yep it works beautifully. That's my new flux cleaning fluid.

 

[Iain McNeill]

we'll leave this thread here for now as it's the high traffic location but angel: you didn't hear it from me) there will be a forum dedicated to construction techniques in the new site.

 

[quasi]

I just use methylated spirits (at least that's what it's called here) and a toothbrush. Works just great although I find it dulls the solder, but that doesn't matter.

Cheers.
Q

 

[gaborbela]

Hello
I use Acetone or Nail Polish and works well .
If you need repeat twice , until nice and clean!
Use a small brush (like used toothbrush), after was with dish soap .
Regards

 

[Sam Lord]

Also works great for ingestion, and nontoxic up to a point for that as well.

+1
The bottle leaks like crazy, there's nothing for it.

 

[dangus]

Isopropyl alcohol, aka isopropanol

Isopropyl alcohol (99%) works (with rosin flux). I'd be afraid that solvents like lacquer thinner or acetone will damage plastic components.

If I'm doing a bunch of boards, I'll pour some alcohol into a tray, let the boards soak, then brush them with an old toothbrush and soak some more if necessary. Blow the dirty alcohol off with compressed air. Spray with clean alcohol, and blow them dry. This usually results in perfectly clean boards.

 

[grjr]

yes, acetone will dissolve ABS plastics so you have to avoid that, I probably should have mentioned that little bit

 

[destroyer X]

Kerozene also helps.

Alcohol is fine too.

Thinner is a little bit agressive..if touches some components may melt plastic cover or numbers printed.

regards,

Carlos

 

[lumanauw]

If the board already contain VR or potentio (with carbon surface) is it OK to soak it too, or the potentio will be ruined?