Question about flux

[Koda]

Ok guys I'm still new to the soldering thing and dknt know what solder I should use. I have two types on hand rosin and zinc chloride inorganic flux. I was told by someone that zinc chloride flux is too strong for general electronics and could eat through copper traces over time but that is more effective at removing oxides then the rosin. Could anyone point me in the right direction??

[mariushm]

Re: Question about flux

Read this:

https://cdn.badcaps-static.com/pdfs/...21d3b7fd1e.pdf

http://www.ehow.com/list_6361756_typ...ng-fluxes.html

It's not comprehensive but it's good enough.

Basically, there's several types of flux, some attack the surface in time so after soldering you need to take it off using cleaning solution ( i think a simple solution is a mix of isopropylic alcohol and acetone), there's some flux types that are somewhere in the middle and then there's other flux combinations called no-clean or water soluble..

Quality solder wire has flux in the middle of it so in this case you shouldn't have to add flux separately.
I don't know what to tell you about zinc chloride flux...

You can see here various types of flux solutions - if you wish, click on the items and you have the datasheets there - they may explain more about the composition and its effects.

http://uk.farnell.com/jsp/search/bro...atchallpartial

And here's for example a quality solder wire with non-corrosive flux inside it (read the datasheet if you wish) : http://uk.farnell.com/multicore-sold...250g/dp/419552

And when you have time, i recommend watching these:

http://www.youtube.com/watch?v=J5Sb2...ayer_embedded#! (at about 10:00 in, it explains about solder wire and flux)
http://www.youtube.com/watch?v=fYz5n...layer_embedded
http://www.youtube.com/watch?v=b9FC9...layer_embedded

[Agent24]

Re: Question about flux

Zinc chloride flux doesn't sound like anything I've ever used on electronics. Is it an acid type? you're not supposed to use those. They're more for general metalwork and plumbing etc.

[ThePCDoctor]

Re: Question about flux

After working on printed circuit boards for over 30 years, I finally settled on "Ersin Multicore, SavBit" solder. No extra flux is required and the solder contains copper, so it has an affinity to copper clad boards and copper wires, and also prevents the erosion of your soldering iron bit, as so many other solders will do. I'll not use anything else.

Just one old tech's opinion.

[PCBONEZ]

Re: Question about flux

Zinc chloride flux is an acid type.

[mockingbird]

Re: Question about flux

Acid flux works wonders if you're trying to desolder something that's near a grounding plane, but be careful, it can eat the laminate.

It's also great if you want to use a low-wattage iron to desolder lead-free solder.

You can use it in electronics, just make sure to wipe it thoroughly with acetone afterwards.

[Agent24]

Re: Question about flux

After working on printed circuit boards for over 30 years, I finally settled on "Ersin Multicore, SavBit" solder. No extra flux is required and the solder contains copper, so it has an affinity to copper clad boards and copper wires, and also prevents the erosion of your soldering iron bit, as so many other solders will do. I'll not use anything else.

Just one old tech's opinion.

That sounds like good solder, but don't you still need some extra flux when doing things like drag soldering on SMD ICs etc? Or are you speaking only about through-hole here?

[momaka]

Re: Question about flux

That sounds like good solder, but don't you still need some extra flux when doing things like drag soldering on SMD ICs etc? Or are you speaking only about through-hole here?

Probably.
Soldering small SMT components without flux is a really bad idea - I know because I've tried that before. It's not impossible, but it's very frustrating, especially when trying to solder those tiny SMT ceramic caps.
The stuff I use for soldering SMT components is no-clean flux from MG Chemicals. It works great. In fact, I like it so much that sometimes I use it on regular through-hole projects as well. The solder joints always end up looking right (nice and shiny too), even though I use lead-free solder.

[Koda]

Re: Question about flux

Zinc chloride flux is an acid type.

Actually it's not acid based, on the label it clearly reads "Does not contain acid"
It's an inorganic heavy mteal based flux. Although it does not contain acids it is still corrosive. I used it and it did a good job. And alcohol seems to remove the residue without problems.

[PCBONEZ]

Re: Question about flux

You've been lied to.
Your second clue was that it's corrosive.
The first was in post 5.
.
Zinc Chloride + Water => Hydrochloric Acid + Zinc Hydroxide.
http://www.superiorflux.com/sold_soft.html

.
That alcohol you use has water in it.
You are making Hydrochloric Acid on your PCB when you clean it.
.
Use Rosin Core for anything electrical.
.

[Krankshaft]

Re: Question about flux

Kester 44 is a rosin based multicore solder. It is clearly stated in the datasheet that the flux residue is non corrosive and non conductive and can be left on the PCB. I'd say this applies to most rosin based solder fluxes.

I clean my joints occasionally with a can of flux remover and a nylon brush just for looks not because I have to.

Stay away from water based (no clean) fluxes. Don't bother with them I once got a reel of no clean flux by accident and the joints were horrible. The joints were so dull looking I thought I was working with lead free.

If your solder is not for electronics use just buy a new reel it's not that expensive. If whatever you're repairing is worth fixing do it right with the proper flux.