Solder question

[tonedawg]

I've been using Kester 24-6337-0010 44 Rosin Core Solder 63/37 for a while and while it works well it leaves a huge amount of flux residue behind that's very difficult to clean. Is there a "cleaner" solder that I won't have to use so many chemicals and scrubbing to clean up after?

[PRR]

What does the datasheet say to clean it?

Kester makes way too many variants. The one sheet I snagged at random describes a water soluble flux, a Kester chemical, water a little too hot for bath, and a toothbrush. But they may have EZ-wash and too-tough variations too. So start with the datasheet.

Remember that none of the Kester electronic fluxes will rot the copper off the PCB. It is boiled pine-sap with a little acid kick. Not the strong acid plumbers use. You wash for super high impedances (really higher than most e-guitar work) or for appearance.

I used to buy different solder on a whim but today, geesum! $25/lb? Down from $40/lb in recent years?? That's 3X to 10X what I used to pay when I was using a reel a year. (Well, yeah, gasoline is 10X what I used to pay too.)

[amptramp]

I used to watch the technicians clean flux off circuit boards with trichloroethylene.  They had little cubic plastic bottles with a pump built into the top surface and they used a stiff bristle brush to do the cleaning.  You just push down a couple of times with the brush and the entire metal top of the plastic bottle moved down and up and pumped new solvent to the top.  This was used on aircraft and spacecraft circuit boards but I doubt they can still use the stuff as it is linked to kidney cancer.

I never used to clean flux off the boards at all.  The circuitry that I was working on was mainly old radios with point-to-point wiring.  Even if the flux became conductive, it was on a tube socket pin or a terminal strip and never bridged any other conductor, so you could leave the stuff on with no effect.

[mozz]

Not sure about that model number but some have 1% flux other may have 3% or more. They have datasheets on their website.

[duck_arse]

at my first job, the ladies had a plastic 20l drum cut in two - one half was half-full of clean freon, the other had dirty freon, with all the flux residue in it. they'd scrub the boards with a nailbrush, rinse with clean, stick in a rack.


but they always had the window open, so it was ok.

[davent]

For removing flux, after it harden  i'd pop it off with a dental pick followed by a small artist brush with the bristles chopped down almost to the ferrule to clean off the dust. Solvents always left a mess that then needed to be cleaned off.

[iainpunk]

i recently picked up a roll of lead free solder, and i expected agony, but i was extremely pleasantly surprised with how great it works with my wireless soldering iron. its some cheap 99/1 solder, probably not going back tbh.

cheers

[danfrank]

Not sure about that model number but some have 1% flux other may have 3% or more. They have datasheets on their website.

Correct, and this is what to look for. With Kester, "44" is the type of flux, 44 being rosin or boiled pine sap. But there is another number in the coding, it used to be more prominent on the label.
"66" is 3.3% flux
"50" is 2.2%
And then they have another number for less flux, but I can't remember what it is. Maybe Kester got rid of this second number in order to avoid confusion. My "new" roll just says the percentage.
In my experience, the "50" or 2.2% flux is more than enough flux to solder most electronics. It leaves much less residue than the 3.3%

[stallik]

When I create a 'good' solder joint, with just enough solder and correctly heated pad and component lead, I end up with very little excess flux. If I put gobs of solder on a joint, that's when the flux ends up everywhere. Just saying.

[blackieNYC]

If you clean right after you solder, isopropyl alcohol is the only chemical needed.  Use a toothbrush.