Flux for electronics.

[tflnemesis]

Hi All, I am hoping someone in the know might be able to answer this as my google fu is not turning anything up that seems relevant.

Can I use plumbers flux with electronics?

The stuff I am talking about states on the tub NON- ACID, Non- Toxic.

Everything I have read on Google says the ACID in plumbers flux is far too aggressive etc etc etc.

Now I do have a small pot of electronic soldering flux I got as part of a Clarke soldering kit a few years ago which works fine, but this tub of plumbing flux I have found is very much softer and a lot easier to apply. Will this plumbing flux be ok or do I need to keep using the elctronics flux?

Richard

 

[brightspark]

rosin flux is the best to use if u need extra for electrical components on pcb etc

 

[MattF]

As BS says, rosin flux is the norm for electronics. Just dip the end of the solder in it before you tin or make a joint. Why aren't you using rosin/flux cored solder, btw?

 

[Jetex]

Why not just use flux cored solder if you are soldering electronics?

 

[tflnemesis]

I am using rosin cored solder, but for surface mount components I find it makes a better joint if both parts are tinned before hand and then a little flux so i can just heat them when installing.

 

[angellonewolf]

I'm not a know all in this but I think plumbing flux is a lot more abrasive than soldering flux and could harm more then help in the soldiering

 

[Seadog]

You need some re-working flux.

For example - https://www.kester.com/products/product/rf771-rework-flux

 

[Jetex]

For surface mount maybe its best to use the solder paste and then re-flow it with hot air or IR heat. There maybe no reason why you cannot use plumbers fluxes if that is all you have but you will need to wash off the flux afterwords as it will most likely corrode with time.

 

[angellonewolf]

Get a good quality flux and a small brush wipe a little on and go ahead

 

[MattF]

I am using rosin cored solder, but for surface mount components I find it makes a better joint if both parts are tinned before hand and then a little flux so i can just heat them when installing.

I'd be tempted to just add a dash of solvent to your flux if you want to soften it. Something like pure turpentine won't damage the components or board, and shouldn't flash off when heated. Don't quote me on the flash thing though. Or, just warm the flux slightly during use.

 

[eSCHEn]

You can make your own rosin flux by grinding a rosin block into powder and dissolving it with IPA.

Having done it though I wouldn't bother. Just get a wee tube of the no-clean stuff. Much nicer to use as the rosin is mega sticky being tree sap based.

 

[julianf]

People debate solder so much -

I used to earn pretty much all my wage from assembly. For most of the time id still be using a 20 yr old antex iron. For all of the time id just be using Rapid's own brand lead solder.

(the stuff i was working on was not ROHS compliant and did not need to be)

 

[rtbcomp]

I assembled some pipework and fluxed all the joints up with Fry's flux, left it overnight to solder it all up in one go the next day. When I got back all the joints had turned green and I had to dismantle the lot and start again, so plumbing flux is quite corrosive.

For electrical/electronic work I always use cored solder or liquid flux from RS and the like that is specifically formulated for that purpose.

 

[ajlelectronics]

Solder paste is designed for the job and so much simpler. A dab on each pad and a hot air gun will give perfect joints and no corrosion. Quick, simple and reliable.

 

[daedalusminos]

I assume you're soldering SMD to PCB's - might be an idea to change your technique. I use the iron to reflow the solder on one pad whilst having the component in position and held with tweezers, this way you can 'tack' the component in place. Now move to the other end and and make the joint correctly with solder and iron and then back to the first terminal to re-make the tacked joint with solder and iron. If your boards do not have enough solder from the manufacturer (or have gold, silver or tin finish) then you'll need to pre-tin the PCB pad with a minimal amount of solder.

No need for extra flux except when soldering IC's where I use a flux pen and the 'drag soldering' technique

I agree solder paste is the best way to go if you're doing lots of assembly.