Author Topic: can corrosion get worse  (Read 1433 times)

0 Members and 1 Guest are viewing this topic.

Offline amateur_25Topic starter

  • Regular Contributor
  • *
  • Posts: 106
can corrosion get worse
« on: January 08, 2019, 09:50:48 pm »
Hi

I was watching one of louis rossman videos about drying out electronics is a bad idea.

I once dried out a phone, it did work afterwards but unfortunately the liquid went into the lcd.
Let's say corrosion damage did occur and I did nothing about it, would it get progressively worse then eventually die?
 

Offline Brumby

  • Supporter
  • ****
  • Posts: 12413
  • Country: au
Re: can corrosion get worse
« Reply #1 on: January 09, 2019, 01:57:35 am »
I was watching one of louis rossman videos about drying out electronics is a bad idea.

What process was discussed?  (This is extremely relevant.)  If it was the "chuck it into a bowl of rice" idea, then it is pointless to do it.  Any "success" people talk about is irrelevant and almost certain to be short term.

One of the most significant and immediate factors that Louis points out is that any liquid landing on powered conductors is going to result in electrolysis, with the subsequent anodic and cathodic reactions.  In short, the current from the battery will eat away at conductors and create crusty deposits.  The first thing that needs to be done immediately after exposure to the moisture is get power away from the circuit.  Unplugging from a charger (if in use) is obvious - but the battery pack needs to be pulled as well.  In the case of equipment with a CMOS/RTC battery, then that should be removed too.  In this effort minutes definitely count, but damage can be done in seconds.

Once power is completely removed, we now look at the corrosion risk.  The enemy in corrosion is moisture.  Trap moisture around bare metal and corrosion will ensue.  This is where proper drying out comes into play.

However, often it is not simply a matter of just letting water evaporate.  The offending liquid will most likely have carried in some contaminants - some dissolved, some just washed in.  Then there are the corrosion products that will build up.  All these contaminants need to be removed - otherwise they will just provide an environment to hold moisture and keep it in close proximity to those metal bits we want to preserve ... such as PCB tracks.  In short, ANY sort of crud left behind is a bad idea.

One big challenge is getting the moisture and contaminants out of small spaces.  Blame capillary action for this.  Sometimes you will get cosmetic damage - such as water stains in an LCD - and sometimes it will get stuck in vias, under screws, in between parts that fit together, but have a small gap - or some other undesirable location.  Disassembly is the best option - if it can be done.  The general application of a non-threatening liquid, such as isopropyl alcohol, to "wash away" the water is usually involved in any case and you can try to get this to deal with tight spaces - but it can sometimes be a matter of crossing fingers.  In doing so, never forget about dislodging and removing contaminants.

The use of immersion/ultrasonic PCB cleaners is not one I would recommend unless you know the treatment is safe.  I've not had experience using these, so will err on the side of caution.

So, in answer to your question:
Let's say corrosion damage did occur and I did nothing about it, would it get progressively worse then eventually die?
Almost certainly: Yes.
« Last Edit: January 09, 2019, 01:59:09 am by Brumby »
 

Offline james_s

  • Super Contributor
  • ***
  • Posts: 21611
  • Country: us
Re: can corrosion get worse
« Reply #2 on: January 09, 2019, 02:45:20 am »
For what it's worth, I've dried out lots of electronics that got wet and had no further issues with them. The trick is to get *all* the water out, it can hide for quite a long time under ICs and other components, and powering it with water in there is what causes it to corrode. Once you remove all the liquid the corrosion shouldn't keep getting worse.
 

Offline gnavigator1007

  • Supporter
  • ****
  • Posts: 374
  • Country: us
Re: can corrosion get worse
« Reply #3 on: January 09, 2019, 03:23:32 am »
I was recently asked to fix a laptop by a friend with a real talent for destroying them and other electronics with liquid. Have had to repair several liquid damaged laptops of hers over the years, but this time she swore up and down that nothing had happened. She'd put it to sleep as she was going to bed and the next day it wouldn't turn on. When I opened it up the same day I was absolutely blown away by the amount of corrosion and general filth. By far the worst I've seen. I believe her about when it died and what happened, but she or someone else definitely dumped something into this poor laptop previously.  The thing that amazes me is that it had continued working at all in that condition. I took plenty of really disturbing microscope pics to shame her with  :-DD Luckily, I managed to save everything from the drive. While I'm normally up for a challenge, there was no way in hell I'd even attempt more on that thing. Could have been saved had it been cleaned thoroughly before the corrosion set in, but I'm really quite impressed it managed to survive as long as it did in such a state
 

Offline james_s

  • Super Contributor
  • ***
  • Posts: 21611
  • Country: us
Re: can corrosion get worse
« Reply #4 on: January 09, 2019, 05:38:45 am »
Sounds like someone who needs one of those ruggedized laptops meant to tolerate this sort of thing, if breaking laptops is a frequent occurrence then it wouldn't take long for an industrial laptop to pay for itself.

I never have understood why some people have such a hard time taking good care of their expensive gear though. I typically keep my laptops and mobile phones for ~5 years and when I upgrade it's because tech has moved on and they're so slow that they're nearly unusable, I've never broken either one. 
 

Online Psi

  • Super Contributor
  • ***
  • Posts: 10385
  • Country: nz
Re: can corrosion get worse
« Reply #5 on: January 09, 2019, 06:33:01 am »
If you dry out wet electronics you are evaporating the water, but that just makes the solution more concentrated with salts and heavy metals.
If you wash it in isopropyl alcohol it displaces the water and moves it out along with the salts.
Greek letter 'Psi' (not Pounds per Square Inch)
 

Offline james_s

  • Super Contributor
  • ***
  • Posts: 21611
  • Country: us
Re: can corrosion get worse
« Reply #6 on: January 09, 2019, 06:34:02 am »
Plain old tap water here has very little in the way of salts or minerals, but that will depend heavily on where you are.
 

Offline Rick Law

  • Super Contributor
  • ***
  • Posts: 3490
  • Country: us
Re: can corrosion get worse
« Reply #7 on: January 10, 2019, 07:37:50 am »
Like a deadly wound - the first few moments are critical.

If it was cared for nicely and immediately after wetting, you have a chance of having it recovering.  About 15 years ago, my Treo 650 took a swim - I am still using it not as a phone but for the video poker game on it.  I still play it almost every day...

About 15 years ago, I was at the beach with my Treo 650 in my back pocket.  A wave got me and I ended up falling full in and totally wet.  By the time I got out, sea water was dripping out of my Treo.

After getting back on shore, I immediately went over to the fresh water feet-wash area to flush the Treo's out.  Since I was very far from home, I know I wont be able to deal with it for at least a full day.   I took out the battery.  Since it is a sealed battery, I can easily clean and dried immediately.  With the Treo, I already knew sea water got in.  After the fresh-water flushing, I pack it wet and ensure it had enough water to stay wet.  I decided to keep it wet because (when I was a professional photographer for a while in early 1970's) we had a camera that felt into a river.  The Nikon tech recommend we keep it in a bucket of water and take it to them in a bucket of water.  I was confused at the time, but after a moment of thought, I realized the dried out grains of salt/dirt sticking to whatever surfaces it can and probably would be killers.

I got home the following day, took the Treo out of the wet packaging, flush it with fresh water again.  I disassemble it and then carefully wash it out again (a few times) and the final couple of washes with alcohol. 

After a day or so of drying out - it works.  The screen got a visible damp mark on it initially, but in time, that fully gone away.  It is still working well, and I play my video poker on it whenever I have a few moment too short to do anything else useful but too long to sit and do nothing.
« Last Edit: January 10, 2019, 07:39:22 am by Rick Law »
 
The following users thanked this post: tooki


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf