Ultrasonic Cleaning??????

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No expert here, but unless you're using a high power industrial unit, it shouldn't hurt anything. The problem is getting water where you can't get it out. I'd never dip an entire scope or plug-in because if water got in the pots, you'd never get it out. Typically the bodies on the old AB pots were sealed with coating of shellac or something, but not the shafts. Careful spraying down and compressed air drying is pretty common. A toothbrush is useful. I can't see any problem with sockets as long as you remove the tubes. A standard test for ultrasonic cleaners is to dip a piece of common aluminum foil in. After a minute it should be wrinkled and perforated- you'll see light right through it! That should give you a good idea of what not to put in an ultrasonic cleaner.
 
So if I were to clean a double sided circuit board....

ground planed, plated through hole with transistors, zener diodes, diodes and all epoxy dipped components (ie capacitors, resistors) then it shouldn't hurt anything??? The foil won't separate from the fiberglass?? I should worry about rubber plugged electrolytic capacitors like nichicon 105 degree radials-or axials???? The only pot is a 15 turn Bourns. What would it do to Berrylium oxide paste on the power transistors? Thanks so much! Ray
 
I'm not sure if you can use ultrasonics with an alcohol (like isopropyl, ethyl), but we threw whole computer motherboards, power supplies, etc. into that stuff. Somewhere I've seen pictures of laptops running (sans hard drive) immersed in it! As long as it's above 90%, it shouldn't produce much more water damage than a humid day.
 
Sounds like you are thinking of a freon degreaser, those things were cool, but have now probably gone the way of the buggy whip.

We had those in the 80's when I worked in the aerospace industry, and they cleaned nasty looking PCB's in no time, but probably blew a big hole in the ozone layer above the plant where I worked.:D

I recently cleaned the pots from my Hickok tester in a small ultrasonic cleaner using simple green, it worked great, just don't leave the item in the cleaner too long.....and rinse and dry well.
 
No! No freon TF! What solvent to use? I'm not trying to get the EPA mad at me.

just trying to clean 6 circuit boards on 6 amps that have been stored and gotten dirty and dusty. I have to replace the electrolytic caps as they are now 30 years old. They just power sub woofers. What would be a good, quick drying, legal solvent?Thanks
 
grhughes said:
Is anyone here an expert with ultrasonic cleaning?

Hi grhughes ,

I have a lot of experience cleaning electronics stuff ,
since I do any restoration , repair and up-grade as my
normal job.

My advices for you are the following :

1) It’s a very good practice to clean PC boards , mainly
if they are made of glass fiber , because if they are dirty , dusty
and mildewed or musty , it will create leakage paths , and
you will hear a lot of “pops” , “cracks” and others exoteric
noises .

2) Regarding the case , I usually do one / two of the actions below :

a) Fill a glass pan ( may be a Pyrex one ) with isopropylic alcohol
( NEVER USE ETHYLIC alcohol ) , and then take the PCB into
the alcohol . Wait for while and then wash carefully with a soft
brush ( may be a common paint brush or even an old tooth
brush ) , in all directions , all components and both sides . If
necessary ( in the case of a very dirty PCB ) , change the
alcohol , and restart all the process . After all done and
cleaned , take off the PCB from the alcohol and dry it ( VERY
WELL ) with a hair dryer .
NO FEAR , because the hair dryer temperature will not cause
any damage to the board and / or to the parts ) .

b) In the case of a VERY , VERY dirty PCB , BEFORE the step
above mentioned , I pulverize it , with the isopropanol
through a painting air pistol , calibrated at 120 psi of
air preassure , and then go to the step a)

OBS. : Do not worry about electrolytics , or ANY other parts
( EXCEPT power or output transformers ) because the
isopropanol does not “ attack “ them in any way , NOT
even the serigraph marks on the components .

IMHO , you must forget about ultrasonic cleaner , because this is
an industrial process , and you have to know the exact rate of
POWER ( of ultrasonic waves ) , the exact BAND of FREQUENCY ,
the proper LIQUID CLEANER ( or SOLVENT )and the TIME of wash ,
or in other way , you can ( .... and certainly will ) cause damages to the PCB and / or the parts , due mainly to the cavitation phenomena .

Regards ,

Carlos
 
FWIW - I once read about a guy who stuffed the whole guitar amp chassis in the dish washer!
I have tried it several times with dirty boards, and it actually works very good!
Obviously there are some components like transformers etc. that are unsuitable for this process and needs to be removed first. Just let the process work, and leave to dry properly before use!
Water and detergent usually don't harm anything that's not powered!

EDIT: I don't think i'd put my scope in there, though......
 
boywonder said:


We had those in the 80's when I worked in the aerospace industry, and they cleaned nasty looking PCB's in no time, but probably blew a big hole in the ozone layer above the plant where I worked.:D



The real industry degreaser was a triclorethylene bath (now banned) and it stripped anything organic. And yes it did blow a hole in the ozone layer. If one smoked in presence of the fumes (which in some places was quite common) and inhaled, it formed phosphene. So much for Health & Safety from 1950,60'70'80' never really woke up to this danger.

Acetone can be used on pcb but often leaves a residue and will dissolve certain plastics. Don't use it on polystyrene caps !!!

richy
 
Re: Thanks Carlos!

grhughes said:
What kind of air pistol (brand) do you use?

Hi Ray ,

Nothing special at all !!! A common painting air pistol for
domestic jobs purpose , works very well .

The secret is to adjust the spray jet for a consistent amount
of isopropanol being sprayed out , and the 120 psi of air
preassure , will do the rest of the job .

As I had said , you can aid the cleanness with a paint brush ,
it is very useful .

Do not waste the alcohol , that is being sprayed out , you can
recicle the liquid , filter it ( use a paper filter ) , and use it again
until you see that it is dirt saturated .

In my experience , you will spent aprox . 2.5 – 2.7 liters ( 3 / 4
Gallon ) of isopropanol , to clean all the 6 PC boards .

Regards ,

Carlos
 
AuroraB said:
I once read about a guy who stuffed the whole guitar amp chassis in the dish washer!

Hi AuroraB ,

I do not recommend to do that , because the special soap , used
in dish washers , has a extremely high amount of Sodium Sulfonate , that strongly “ attacks “ the lead and the tin on solder joints .
Instead , you can use pure water and a neutral soap , and dry all the stuff , very , very well , BUT the cleanness will not be so good
as that made with isopropanol .


richwalters said:

Acetone can be used on pcb but often leaves a residue and will dissolve certain plastics. Don't use it on polystyrene caps !!!

Hi Richy ,

Totally correct !! But the acetone vapor is very intoxicating and
highly flammable .


nhuwar said:
I use methanol, toluene and acetone as my major cleaners.

Hi Nick ,

Sorry to say that , but I can not believe in it . All the three liquids
are VERY , VERY INTOXICATING and can cause irreparable
damages to your health .
Please be very careful to handle with them and use the proper
protection , on nose , mouth , eyes and hands .
Methanol and Acetone are highly flammable .
Unless you are an experienced chemist .


In time : The Isopropylic Alcohol is very flammable too ,
but not so much like acetone and methanol

Regards for all ,

Carlos
 
refference said:


Hi AuroraB ,

I do not recommend to do that , because the special soap , used
in dish washers , has a extremely high amount of Sodium Sulfonate , that strongly “ attacks “ the lead and the tin on solder joints .
Instead , you can use pure water and a neutral soap , and dry all the stuff , very , very well , BUT the cleanness will not be so good
as that made with isopropanol .




Hi Richy ,

Totally correct !! But the acetone vapor is very intoxicating and
highly flammable .




Hi Nick ,

Sorry to say that , but I can not believe in it . All the three liquids
are VERY , VERY INTOXICATING and can cause irreparable
damages to your health .
Please be very careful to handle with them and use the proper
protection , on nose , mouth , eyes and hands .
Methanol and Acetone are highly flammable .
Unless you are an experienced chemist .


In time : The Isopropylic Alcohol is very flammable too ,
but not so much like acetone and methanol

Regards for all ,

Carlos

They aren't that bad if you know what you are doing with them. I work with many chemical much more toxic and dangerous then them. I have been working in chemical labs for over 10 years.
These 3 chemicals all have special purposes.

I to also think trichloroethane is a very good cleaner and it is not illegal in the US, you can still get it. The good thing about it is it is not flammable.

If you really want to stick with a friendly volatile use propanol, is pure isopropyl.

There are far worst cleaners and solvents then the ones I have mentioned.

Nick


Nick
 
In the "good old days" one could dip electronics in Carbon tetrachloride.

It was a great cleaner if you could get past the damage to your health.

Now that I give it some thought, I recall it was pretty nasty on some plastics.

As a kid we put it in squirt guns and killed bees. Until the guns melted in our hands.
 
kuroguy said:
R134a boils at -16 degrees F. It would simply boil off at atmospheric pressure and likely freeze whatever it came in contact with (like your skin).


I know, but the original freon worked very well as a de greaser. I wonder how 134a would do.

Oh and that 3m cleaner I was talking about before wasn't made by 3m. The stuff is called Vertrel XM and it's made by Dupont. It's supposed to have 0 negative environmental impact.

But I can't say how it works since I haven't tried what I have yet. It's supposed to be the Jim Dandy though so I need to give it a whirls soon. It's I'm and alcoholic when it comes to solvents LOL.



Nick
 
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