Flux remover keeps leaving residue

[Maxxarcade]

I'm having trouble with flux remover lately. For some reason, it keeps leaving a white residue, almost powdery texture on whatever board I try to clean. I've tried a couple different methods, using both Chemtronics Flux-Off and regular denatured alcohol. The resulting residue looks like corrosion when it dries, and it's driving me crazy. The boards look better with flux on them than they do with this damn residue

Is there anything I can do to fix this? It seems to be worse on certain boards than others. I'm trying to clean them up for a finished appearance, so this bothers me.

[stretch0069]

Re: Flux remover keeps leaving residue

I've had problems with that residue, but not all the time. Must be different flux formulations??? I had to use a lot of alcohol and brushing in one direction toward the nearest edge of the board. Still ended up with some here and there.

As of late, I've been using a water based flux. After soldering, I just grab an old toothbrush and put it under running water....not real hot, but reaaally warm. I've had no problems with residue at all.

[Maxxarcade]

Re: Flux remover keeps leaving residue

The solder I use is Kester 60/40 rosin core, Maybe I need to get some different solvent? I'm thinking of trying the 63/37 solder too.

[MixMasta]

Re: Flux remover keeps leaving residue

Thats exactly what I use too and I haven't had any problems... though I don't do any repairs near as complicated as you probably do.

The solder I use is Kester 60/40 rosin core, Maybe I need to get some different solvent? I'm thinking of trying the 63/37 solder too.

[starfury1]

Re: Flux remover keeps leaving residue

Cant really help you with the flux issue, you are using what I would try. apart from possibly metho then alcohol

I suspect stretch maybe on the money here with a flux formulations? may have been changed.....but I don't know


60/40 solder was the norm due to it having a small plastic state between liquid and solid
which I understand was better.

63/37 has minium plastic state which if memory serves may result in a higher amount dry joints being made. (which is why 60/40 ratio was chosen for electronics work)

I would have to check this and I will stand to be corrected but like I said,
thats the story if memory serves me.

Anyone know if RoHS has resulted in any flux formulation changes off hand?

cheers

[starfury1]

Re: Flux remover keeps leaving residue

As I said I could be wrong

on this page

Tends to support the above about statement about 63/37 solder ,
see SOLID, PLASTIC and LIQUID

This page tends not to here
See "'Solder Types"

Me I use 60/40 but like all of us soon, will be forced to use RoHS spec

Sure others here will have good input on the pluses and minuses of both types

Cheers

[dungbeetle]

Re: Flux remover keeps leaving residue

That was some interesting reading on the solder and flux types. Now how do we know if we have 5 core flux??