PCB Ultrasonic Cleaner Recommendation?

[coppercone2]

Fyi I would not be surprised if those isreali instruments were run over by tanks before sale.

I think also if a transistor has been overloaded alot and stuff like that, there is strain in there that will make it more susceptible to ultrasonic damage.

I ultrasoniced an amplifier I got from Israel that was mad filthy but it was OK afterwards, but it is a lower frequency type (MHz). Not sure I wanna think about what kinda nasty shit might accumulate in old IDF equipment anyway

And are you sure the transistors were functioning properly? If its really dirty they coulda been shorted out by grime coupling small signals making something kinda work


Mmm but the bigger problem I have with ultrasonic is that sometimes it rubs text off things. I never had damage but the text being removed is a serious hindrance, and you should probobly make a diagram of what part was where before engaging in heavy cleaning, that can RUIN your day. I use simple green with a brush to do boards that I am worried about text. The problem is usuaully/always metal can transistors. They used to like ink it back in the day. Transformer bodies too. And of course if there was seal failures in the parts due to strain and liquid got in there..

did you try baking the board? After ultrasonic cleaning I always do a clean water dip (preferrably a clean water ultrasonic for a min, requires tank switch), to help dissociate all the contaminates into the clean water under high preference for osmotic flow, then bake at a low temp (40C+). Just make sure you dont trust any oven ever, I think I damaged foil caps that way. To get rid of all the humidity you would need to do the 'pre soldering' procedure you do with damp SMD parts on the whole PCB.

[helius]

Not sure I wanna think about what kinda nasty shit might accumulate in old IDF equipment anyway

Matzo balls?
I have seen some heavily beat equipment for sale from Israel, but it doesn't appear to be treated any worse than ex-military gear that was used in the field from other countries. The difference may be the legal allowances (or chutzpah) placing the equipment for export sale. Many other countries do not allow export of mil surplus.

I use simple green with a brush to do boards that I am worried about text. The problem is usuaully/always metal can transistors. They used to like ink it back in the day. Transformer bodies too. And of course if there was seal failures in the parts due to strain and liquid got in there

Simple Green is an aggressive cleaner containing butyl ethers, similar to Goof-Off or graffiti remover. I'm not sure it belongs in an electronics shop.

[coppercone2]

maybe it used to contain butyl ethers, the formula was changed since then, I think since 2003

https://en.wikipedia.org/wiki/Ethoxylation#Alcohol_ethoxylates

Anyway, its great stuff, if you spray down a PCB with a squirt bottle and brush it with a bamboo bristle brush, its enough to rinse it with hot water to easily clean a 17 inch chassis in a kitchen sink.

Metal cans that are labeled, only some types of labeling, on the older parts (germanium age), the ink is sensitive to the modern formula of simple green, if its hot, and used for a long time, but usually the text is in BAD SHAPE to begin with, whenever I see that initial quality of labeling I try to scribe over it with a engraving tool.

I have not seen any damage to silk screen, plastic parts or modern metal parts from a short ultrasonic clean with it. It also works on tobbaco pipe condensate, leaked capacitor goo and chemically weakened flux (like flux that gets puffy from solvent) and weakened conformal coat also comes off. Keep in mind its a concentrate and used very dilute.

[EEVblog]

Old thread, but no point making a new one.
I trust Chemtools here in Sydney, but anything else worth considering?
https://www.chemtools.com.au/product/electrical-electronics/cleaners-flux-removers/pcb-flux-remover/

[jpanhalt]

If you want a water-based, non-ionic cleaner, cellosolves (https://en.wikipedia.org/wiki/Glycol_ethers) are hard to beat IMHO.

As I have mentioned many times, acrylic floor strippers and Kester water-based flux cleaners are based on them.  By far the most common is butyl cellosolve, which has a distinctive order.  A final concentration of about 10% butyl cellosolve works.  Even a lower concentration works.  I would not recommend going to higher concentrations and definitely not neat.  They will remove cured enamel when neat.

Both Kester and floor stipper contain a little ethanol amine or similar as a "saponifier."

I noticed recently that very thin gold flashing may also be removed.  I was cleaning a solderable SparkFun protoboard and after 2 minutes, the gold looked a bit like nickel.  Thirty seconds may be enough for flux.

Boards come out remarkably clean and hydrophobic.  I rinse briefly under a sink faucet, then once in the ultrasonic with distilled or equivalent water and blow dry.

EDIT: I use ZEP brand heavy duty floor stripper.  ZEP is an international brand, but I was told by a chemist there a few years that it is not sold by that brand in Australia.  It's about 30% cellosolve, so I dilute 1:3 or 1:4 (1 part to total parts).

[coppercone2]

hey yeah also I re read the thread, 20 minutes (3 times!) is ALOT. A few things I saw showed that about 5 minutes is the end of the safe zone for IC!!!

I suggest that you do a soak. Ultrasonic should be fast. If you think you need 20 minutes in a cleaner, try a long soak followed up by say a 1-2 minute clean.

The soap has its own chemical action that is probboly not effected by the sonic energy, that needs time to work too. Jewlery workers often only need 10-15 seconds to get their stuff clean. There is imo a good chance that if you need the whole 20 minutes, a big portion of that time might just be what the soap needs to infiltrate the grime natrually.

And heat too, warm soak. it makes a world of difference with soap if you get it warm.

and despite all the magic properties, its not like it gets rid of the utility of scrubbing. if you mechanically disturb grime with a brush, it will come off much faster.

Where the ultrasonic is good is that it can do the small spots that you can't hit, like under chips, in crevaces, etc. And even so, if you get the right tools (i.e. a soft bristle brush of the correct size, bottle brushes) so you can do a bit of poking under chips and stuff, to kinda disturb the contamination, after the soak but before the ultrasound, it will drastically reduce the time in the cleaner, because you will mechanically push out and break up large chunks that take a while to get 'disintegrated' by the energy without help. For instance, soft bristle brush to poke in under a IC, bottle brush around a potentiometer, etc.



Also the new concern I have with long term exposure is that it could do damage to the plating inside of carbon pots (they have a substrate, and a coating that is resistive. if you leave them in for too long (too lazy to disassemble and scrub (real gentle)/soak a bit, it can remove the coating that does the work, especially if its degraded).

[EEVblog]

Old thread, but no point making a new one.
I trust Chemtools here in Sydney, but anything else worth considering?
https://www.chemtools.com.au/product/electrical-electronics/cleaners-flux-removers/pcb-flux-remover/

I've ordered 5L of this stuff, that at least gives me one option for PCB's.
Can you re-use it? I assume maybe yes depending on conditions?

[notsob]

bulk cleaner (transport) can be a hidden cost with the distances between cities in Australia. I prefer to use a concentrate and mix
with deionised water when I need it.

Another trick is to put the object to be cleaned in it's own (thick/heavy) resealable plastic bag with the cleaning solution and put that into the ultrasonic cleaner filled with water (saves on cleaning solution)

[jpanhalt]

I've ordered 5L of this stuff, that at least gives me one option for PCB's.
Can you re-use it? I assume maybe yes depending on conditions?

The functional components of that cleaner are similar to those in Kester flux removers and floor stripper I use (attached).

Dipropylene glycol monomethyl ether is a glycol ether and a great solvent.  Ethanolamine is the same in each. The sulfonic acid is an anionic surfactant.  It is probable both Kester and floor stripper have something like that too.  I am a little surprised it is used presumably neat as the concentration of the glycol ether is about 2 to 3 times the working concentration of the other two.

As for reuse, I do reuse mine for a few single boards, but toss it when it shows precipitates.  One could probably filter it, but floor stripper is cheap.  I don't do production.    The faucet rinse is pretty effective at removing dirty cleaner.