Kester 63/37 and PCB cleaning

I've noticed that after soldering my joints don't look clean/bright. They look kind of "dark".
How do you clean the joints/ remove flux? In fact is cleaning really necessary?

I'm using this solder, which I'm quite happy with.

This is from the data-sheet:

44 possesses excellent fluxing ability, the flux residue is non-corrosive and non-conductive under normal conditions of use. When exposed to an elevated temperature and humidity environment (38°C, 94% RH) for 72 hours, there is no evidence of corrosion caused by the flux residue. IPA will not clean the residues off the surface of the circuit board after the soldering process. A saponifier or cleaning agent specifically designed to clean a rosin based flux is required to clean the residues. Please contact Kester’s Technical Support for further information.

I'm not sure what they mean by "normal conditions of use". Do they also mean not too high temperature while soldering?

I'd like to hear other people's experience/ techniques.


Thanks!

It's a no-clean flux, so there's no need to clean it. As the data sheet notes, isopropyl alcohol won't clean the flux residue; you need a surfactant-type cleaner.

As to whether the joints "look good," how old is the solder? How do you store it? What temperature is your tip? When we used to use Pb-based solder, we used the Metcal 600° tips. (We are all lead-free now, so we use the 700° tips.)

Andy Peters said:

As to whether the joints "look good," how old is the solder? How do you store it? What temperature is your tip? When we used to use Pb-based solder, we used the Metcal 600° tips. (We are all lead-free now, so we use the 700° tips.)

Click to expand...

No more than a year old
Store it in a room with normal temperature and humididty
Soldering between 300C and 400C

When I'm saying doesn't "look good" I mean it doesn't shine. It looks rather dull if that makes sense.

are you using rohs compliant solder or leaded?

Leaded. It's "KESTER 44". I have a link in the OP.

Cleaning is not necessary with 44,  but  If you want it
to look pretty,  us a stiff tooth brush with alcohol
followed by a tooth brush, dish soap and warm water
bath.  Just watch out for unsealed pots etc.   

have fun..

GARY

Thanks guys, seems like 44 should be OK without cleaning which is good news.

leave the flux on there, guards against moisture in hi Z areas,  unless you are going to wax dip (Fender)  or use a clear coat,

age makes no diff, use 30 yr old solder off evil bay on a daily basis,

Andy Peters said:

It's a no-clean flux, so there's no need to clean it. As the data sheet notes, isopropyl alcohol won't clean the flux residue; you need a surfactant-type cleaner.

Click to expand...

"44" flux leaves a nasty-looking brown crud all over the circuitry.  It may be only a cosmetic problem, but I never saw any mil-spec/etc. circuit boards left with that debris left behind after manufacturing.  For example, look at any circuit card from an Ampex/MCI/Scully tape machine.  No crud.

I don't have the Kester solder roll here at my hacienda, but it is specifically called "no clean" and still leaves a (cosmetic?) bit of smutz behind which I remove with IPA and paper towels. 

"44" rosin leaves brown smutz everywhere which sputters that damned crap everywhere.  Only place that I use that is when repairing ancient point-point gear.

EDIT:  I believe this might be what I've used for many years with through-hole circuit boards, but I need to look at the spool once I'm back in Ye Olde Shoppe:

https://gokimco.com/kester-24-6337-8800-245-no-clean-cored-wire-sn63pb37-50-core-031-dia.html

Bri

I prefer 245 flux for lead alloy solder. The residues are clear and minimal, it truly has no halogens, it's more active than 44, and it's a lot easier on your lungs and throat.

The name '44' comes from the 0.44% of halogens in the formula, which would imply that it's corrosive. However, for some reason, it has shown itself over decades of use to be not corrosive, so it's classified as a no-clean. Still, 44 is less active than 245, and it tortures my throat, and 245 does not.

For lead-free SAC305 alloy, I like their 275 flux.

no clean solder sucks big bananas, our company bought about 20 lbs of the crap and it is still in the stock room, good ol 60/40, been using it for about 50 years now, look at any Fender chassis, tons of brown crud,

It's true that 44 tortures my throat and I don't have a fume extractor but I'm very happy with the way the solder behaves. I find it very easy to work with. The  245 is "No clean wire solder", while the 44 is "Activated rosin wire solder" whatever that means...