Clean PCB which has been in salty water for some time - Page 1
Forum section: electronics / repair

author: todorp
author_rank: Regular Contributor
timestamp: February 27, 2022, 05:39:13 pm
content: Hi all, do you think it is possible to "revive" a battery powered device which has been in salty water?The device has been dropped in the water and then immediately fished out and the battery disconnected immediately. The device however has not been cleaned and has been left as is for a few hours.The question is: what would be a way to wash the pcb from salt residue?Thanks,Todor

author: wraper
author_rank: Unknown
timestamp: February 27, 2022, 05:49:33 pm
content: Salt can be cleaned with water, preferably in ultrasonic bath and with special cleaning chemicals added. However as it was a salty water likely there is a corrosion too, and simple cleaning will not be enough.

author: tunk
author_rank: Super Contributor
timestamp: February 27, 2022, 05:52:19 pm
content: What kind of device?I once tried to "repair" a graphics card which had artifactsby putting it in a dish washer (after removing heatsink+fan).The repair didn't work, but neither did it get worse.

author: wraper
author_rank: Unknown
timestamp: February 27, 2022, 06:16:18 pm
content: Quote from: tunk on February 27, 2022, 05:52:19 pmIf it has artifacts, most likely you need to replace a faulty RAM chip. Not wash it. The only case when it may need washing is when liquid cooling leaked onto it.

author: todorp
author_rank: Regular Contributor
timestamp: February 27, 2022, 06:59:21 pm
content: Quote from: tunk on February 27, 2022, 05:52:19 pmIt is a friend's FireFly 2 vap device..

author: todorp
author_rank: Regular Contributor
timestamp: February 27, 2022, 07:28:35 pm
content: Quote from: wraper on February 27, 2022, 05:49:33 pmThere is corrosion too - is the case hopeless?

author: wraper
author_rank: Unknown
timestamp: February 27, 2022, 08:00:04 pm
content: If it did not destroy any traces or components then cleaning will be enough. However usually you will need to repair what was damaged. Certainly not hopeless, but can be quite tricky, especially if there are small BGA chips.

author: jdragoset
author_rank: Frequent Contributor
timestamp: February 27, 2022, 11:25:03 pm
content: Soak overnight in DI (distilled) water, refresh water and soak again overnightDry in oven 150-180 degrees F for 12 hours.

author: abdulbadii
author_rank: Frequent Contributor
timestamp: February 28, 2022, 12:51:28 am
content: pH balance of the salt residue is bit high (more to be alkaline) and that’s whynormal cleaners may only smear.So suitable cleaner must be low/mild acid pH level, which should neutralize ite.g.vinegar, one of your food in kitchenacetic acid, same, just one not natural, it's synthetic of itboth should be about 33-70% conc.citric acid is alike, some citrus fruit juicesas usual and must: has IPA as a finishing touch

author: jpanhalt
author_rank: Super Contributor
timestamp: February 28, 2022, 01:00:11 am
content: Solder resist is quite hydrophobic. That is, it does not wet. If you can find a non-ionic detergent, I would add some to the first water wash at least. Absent that, then use any convenient liquid detergent.