PCB cleaning.

Oric, yeah but, leaving flux on makes it look messy.... where's that nice smooth clean finish only Isopro...Alcohol can do that with a bit of abrasion ...

Ummm, no. As I said, if you really want a nice clean board, you don't really need to put the gooey flux on there in the first place. Get some aqueous core solder and see for yourself.

If I do wish to have a clean board, for whatever reason

I must admit I'm not that bothered about cleaning a board to make it look nice, but after inspecting a couple of boards under a 20x binocular microscope I was shocked at just how much cr4p was left on what appeared to be clean board. I'm not that worried about flux corroding anything, but I have noticed lots of tiny solder flakes which may cause problems.

I've not heard tell of lots of tiny solder flakes before. I wonder what that's about?

Sounds like a new kind of cereal marketed toward young engineers.

He said he's cleaning his boards, and asked for advice on how to better clean them. As for myself, when using leaded solder, I rarely clean the flux off. Usually it isn't a problem.

For lead-free solder, I use "No clean" flux, or I clean the boards. Lead-free fluxes tend to be much more corrosive.

Why are people saying electrolytic caps are not well-sealed? If they were not, they'd dry out in a few weeks.

oric_dan:
Oh lord, talk about an enormous P!TA. After years of soldering, I disagree with what everyone else here has said [LOL]. I "never" remove the rosin flux, just leave it on. The joints don't dissolve or corrode like some people seem to think.

It's strictly a vanity thing with me, I harbor no delusions of corrosion etc.. I have PCBs, kept in my basement literally for decades, soldered with Kester 44 and not cleaned, that show no sign of problems, the bare copper is even still shiny (homemade boards).

Even though I pretty much exclusively use solder with "no-clean" flux, I still clean it off. Especially on SMT boards, makes them look much nicer.

polymorph:
Why are people saying electrolytic caps are not well-sealed? If they were not, they'd dry out in a few weeks.

Are they sealed well enough to immerse under water? I just assume they are not, at least the through-hole kind. The smt kind may be better sealed.

[quote author=Jack Christensen link=topic=189876.msg1407073#msg1407073 date=1380243795]
I have PCBs, kept in my basement literally for decades, soldered with Kester 44 and not cleaned, that show no sign of problems, the bare copper is even still shiny (homemade boards).[/quote]
Ditto here.

I've not heard tell of lots of tiny solder flakes before. I wonder what that's about?

you can't see them with the naked eye - you need about 20x magnification to see them.

I think what happens is that when I trim off the leads of through-hole components very close to the solder tiny bits of metal get generated by the blades of the wire snippers.

Dust, maybe?

Wet dielectric electrolytic's are liquid tight and there i no issue with liquid immersion. Honestly, I'm trying to figure out where this misconception is coming from. A typical inexpensive through-hole electrolytic has a rubberized base very tightly fit into the molded aluminium can. Sure, electrolytic's have been assembled to allow methods of bursting to occur under dire circumstances, but that does not mean they are not liquid tight.

(deleted)

spycatcher2k:
I buy a pack of tooth-brushes from our local pound store every couple of months, as the Acetone does affect them.

I'd be afraid that acetone would also affect components on the boards.

..... not to mention one's teeth

It definitely does, if you've cleaned with acetone, you'll notice a standard FR4 board will turn a little white. Acetone will dissolve the adhesive that holds the fibgerglass together. This doesn't count any parts. IPA is less likely to do this.
Something I vaguely remember from something like 10-12 years ago, but don't know the validity of it, was to clean with warm distilled water, then use IPA to clean off the water, since it will evaporate much faster.

...clean with warm distilled water, then use IPA to clean off the water, since it will evaporate much faster.

In cleaning boards with spills on them like coffee, soda, etc. I may use 409 set to stream with a toothbrush or part cleaning brush, then flush with distilled water, blow out with dry compressed air, then flush with 99% IPA, then blow out again, finally left to dry.

I find it amusing that coffee and soda on your PCBs is a common enough occurrence that you've developed a procedure to deal with it.

Well, I've worked on a lot of consumer electronics and arcade games. Remote controls are usually caked with sweat, skin, soda, and coffee, and for a while VCRs came with remotes that were not replaceable with a generic remote, and that cost $90 to replace. TVs occasionally get things spilled inside. And it used to be worth it to repair computer keyboards.

And all kinds of consumer electronics get really grotesque in smoking households. Smoke residue and dust turn into a tarlike substance coating everything.

I've been repairing electronics for a very long time. Now pretty much anything acts up, it gets tossed out and replaced, either because the item itself is cheap, or parts are very expensive. I've seen people giving away really large 3D TVs because the cost for a new screen is not much less than the cost of an entire new replacement TV.

mirith:
...then use IPA to clean off the water, since it will evaporate much faster.

Waste of good India Pale Ale. IMHO.