Cleaning solder flux

[j-po]

Should I worry about flux residue corroding joints over time? Is cleaning necessary?

[Structo]

I don't but I think they make something that well clean it off.

It is rosin, I don't think it is corrosive. You know the stuff a violinist rubs on his bow? Same stuff.

[iknowjohnny]

They do make it, but it's the nastiest chemical i have ever used. So much so that i will not use it no matter how much i want to clean up. If you do try it, use it outside and don't breathe in the area you spray it, don't get it on your skin, and just plain be careful. If you breathe in even the tiniest amount you will understand what i'm saying. I'd prefer drinking a vial of acetone to sniffing this stuff !

[Phil_S]

90% isopropyl alcohol on a q-tip. Not the 70% isopropyl rubbing alchohol -- too much water in it. If needed, you can use a spray bottle and a rag. This will take care of most stuff. It dries quickly and leaves no residue. Cheap, too. Careful, it's flameable.

[Aurora]

Whether it's harmful or not, depends on the actual flux in use. Old ones should be removed, among the newer ones are several no-clean types.
Try finding a spec sheet for the solder you do use,

[Bob-I]

Keep in mind that I wenrt to college in the late 60's so lessons learned have changed.

I was taught that more damage may be done by removing the flux, than leaving it. The rule was if it's a one time soldering job, leave it, if you need to repeat it many times, remove only as much flux as you need to make the contact.

We also used alcohol to remove flux if it was necessary. Remember that if any solvent is used, it must be dried completley before applying power. Using water is not a problem at all, but use clear water and make sure it's completley dry.

[Structo]

How about de-natured alcohol?

[Wayne]

My education is a bit more recent (early 90s). Consensus around that time was that flux should be removed with isopropyl and a brush or Q-tip because over time it attracts and retains moisture from the air.

In a pinch, I've used contact cleaner (probably contains isopropyl or something similar) and a balled up piece of a coffee filter.

At one place I worked where we were building smallish boards we just threw the whole board in a jar of alcohol, put the lid on, and gently shook it around a bit. Not sure if all electronics parts are good for immersion like that, but the ones on our boards were.

W

[Aurora]

Rubbing alcohol, isopropyl, pure grain, acetone, nitro thinner etc.
Most will work in most cases- in some not , depending on what type of flux we are dealing with. Some of the more modern are water soluble - and some are no clean. That's why I said to get get spec sheet - if possible. The fluxes used with modern lead-free solder ( which BTW I hate) looks alot worse than it is. Cleaning does no harm, unless it removes coating on a prefab board. A gentle coat of conformal coating is good when everything is proven OK.

[Structo]

Gawd I hate that ROHS solder....
I had to touch up some solder joints on a Crate amp with that crap on there.
When the solder set it all looked like cold joints.....

[Ronsonic]

I remove flux, aesthetics if nothing else.

Acetone and a cheap acid brush with the bristles cut short to scrub.

[skipm45]

I use this. This stuff is the best.

http://www.all-spec.com/1/viewitem/MCCP ... info/i=rss


Skip

[Structo]

I actually don't even worry about it.
I use the Kester 60/40 .031 rosin core solder.

[davent]

Dental pick then a small stiff brush. The flux pretty much pops off with the pick.

dave