Comment by Workaccount2
2 days ago
You are better off soaking the wet electronics in isopropyl alcohol then trying to dry them in a bag full of desiccant.
One of the things that kills wet electronics is the dried residue that is left behind, creating shorts. Alcohol will wash away the water and leave no residue after it dries.
If the device has ink or glue you'd like to try to preserve, deionized water will mostly work too.
One time I tried drying a water-soaked smartphone in alcohol, but the alcohol got under the LCD screen and made it look blotchy permanently. The phone still worked but I stopped using it.
I think the protocol would generally be to disassemble the device and then clean with alcohol. Easier said than done with a phone of course.
Yeah, I've had the same issue; as far as I can tell it's not actually the LCD itself but the backlight and the diffuser that end up getting screwed up. If you're trying to save electronics, keep the isopropanol away from the screen.
"You are better off soaking the wet electronics in isopropyl alcohol."
Where I am ethanol (EtOH-95%, H2O-5%) is much cheaper and much more readily available and works almost as well. If silica gel is not available, then a fan works well followed by a warm (not hot) oven baking. Make sure the alcohol has essentially all evaporated first.
Keep in mind that some components can be affected by both EtOH and propan-2-ol — component markings, coil doping resins can dissolve, etc. Both alcohols are also good at removing solder flux resins/residues. (Oh for the days when freon and freon mixtures were available, component damage never happened.)
Devices with power transformers pose special problems, best to dry with alcohol first (hoping enamel coatings on wire aren't softened), then bake in oven on warm heat for a long while, sometimes 24 hours or more is necessary. With transformers it's important that this is done as soon as possible after wetting.
Edit: as I'm reminded by nyanpasu64 keep both alcohols away from LCD screens (likely all screens). I had a netbook PC and put it in a carry bag with a bottle of EtOH and it leaked. The PC still worked but the screen suffered the same outcome.
That may be country specific, but at least where I live, ethanol is much more expensive than isopropyl alcohol (30€/l vs 10€/l) - mostly because of dues on ethanol.
Right, if you live where duty is applied to ethanol then it's expensive. In Australia, where I am ethanol is available as a denatured product. That is, it includes a very small amount (much less than 1%) of denatonium (aka Bitrex) which renders it undrinkable (it's the bitterest substance known). As such, excise tax is not levied.
Here, one liter bottles of denatured ethanol are available in every supermarket everywhere, and up to 20 liters available in hardware stores (at bulk rates it's even cheaper).
For comparison, here denatured ethanol costs about $5/l [in US dollars] versus isopropyl at between $25 and $30/l.
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Isn't the ethanol denatured? There's a duty on that as well?
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At my work any electronics that have had a water bath or flux-added rework will get an ultrasonic alcohol bath and then a forced air drying run. Alcohol is just so damned good for so much.
I'd be very scared of IPA in an ultrasonic cleaner. Sounds like a recipe for a fire. Or is your machine perhaps designed for safe IPA cleaning?
A few companies do make ultrasonic cleaners that are designed for flammable solvents, but they aren't common.
The easiest option is to just fill a plastic food bag with solvent, throw your part in, seal it with a clip and float it in your ultrasonic bath. The bag contains the vapour for safety, and it's easy to switch between different solvents and solutions.
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I'm scrolling before coffee and initially took your acronym as India Pale Ale, which would certainly be a different cleaning experience...
I've used both EtOH and propan-2-ol (IPA) for decades in ultrasonic cleaners both at room temperature and heated (quite warm to feel but not boiling hot) and never had a problem with fire.
Do ultrasonic cleaners get hot?
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Even more spicy is vapor phase cleaning... evaporate the solvent, condense on the part to be cleaned suspended above it. Very effective since the impurities are constantly distilled out.
Also kinda explody.
The machine doesn't get hotter than 50C. IPA isnt igniting at that temp.
I totally agree though my use of it is pretty different ;)
What percentage alcohol is used?
99%. 70% if I'm doing parts disinfection for medical devices.
usually 99%
Why not demineralized water instead of alcohol?
Alcohol would dry up faster, demineralised water will have more time to dissolve and redeposit particles. Though you have to be careful with alcohol as it can destroy some plastics