34 replies to this topic

[z-axis]

I think I should chime in as my undergraduate degree is in organic chemistry and I worked as a chemist as well. So I spent a lot of time purifying stuff...

Rinse first in copious amounts of distilled and/or deionized water to remove the salts.
Rinse next in isopropyl or ethyl alcohol (everclear) as alcohol dissolves the water.
Next rinse in acetone to remove the residual alcohol/water.
Dry in dessicant or rice or sun/heat for several days.
Coat in protectant if desired.

All done!

[Caustic]

I know myself, chances are that I have alcohol closer than distilled water ....
Also would be wary of diluting the salt so it could fit under pads and in solder flaws, as soon as it mixes with the distilled water, it is no longer clean ...

[Windbreaker]

Caustic, on 05 February 2012 - 02:47 AM, said:

I know myself, chances are that I have alcohol closer than distilled water ....

Oh no! Don't use the "good stuff" for this!

[D-OCHO]

Hey if you guys want to do another dunking see this website about another new waterproofing coating.

http://reefbuilders....dgets-liquipel/

[juz]

thats cool, I will be using some sort of protectant with my next build. I also won't be landing right next to the shore line.

[snafu]

That Iphone demo was discussed last week in water proofing thread .. You have to send your phone off to them and they water proof it..
Juz's Main board actually got a water proof coating of a special electronics Laquer last week ... so it was well timed .. at least the circuit board was sealed..

Trev

[juz]

....warming up the soldering iron now

[Caustic]

If you have money to waste, there is the new nano deposition conformal coating.

The key is to find the proper ones for your usage and that will not destroy your device over time by reacting to components or easily being destabilized. In regards to the CC board, you are going to have a hard time coating it properly due to the connectors. Usually conformal coatings are applied before the connectors are soldered on and then those pads coated after.

[z-axis]

Caustic, on 05 February 2012 - 02:47 AM, said:

I know myself, chances are that I have alcohol closer than distilled water ....
Also would be wary of diluting the salt so it could fit under pads and in solder flaws, as soon as it mixes with the distilled water, it is no longer clean ...

Yes just alcohol would do okay too, I am just providing the textbook proven method of salt and water removal. Do you have some specific empirical evidence to the contrary? Please share because I don't easily accept non-scientific explanations for things that have well-defined properties and behaviors.

And for the record, if salt can get there, water can get there even better. If the salt gets somewhere physically,or delivered in solution, EtOH will not necessarily dissolve it, and it would remain either dissolved or crystallized under your pads and solder flaws, as it was water that deposited it there to start with, and water that left it that allowed it to remain. If DI H2O touches it, the salt will distribute iteslf almost instantly throughout the contigious volume of solvent. Soluble salts want to distribute themslelves evenly according to volume, which is why rinsing three times with one unit of volume is more effective that rinsing once with three times the volume.

So I encourage you to share with me your knowledge of of the topic, as I respectfully accept your challenge that my suggestion is lacking in real world understanding of these specific systems. Seriously, I am just saying that if you reply to me in that way, I would truly thank you for sharing what you know with me and others because you imply that you know specifically about electronics and salt water. What am I missing?

[Windbreaker]

Flushing with water is what we would do whenever a camera (mechanical SLR still camera) was flooded during a dive.

It's not easy dunking a camera and lens in  a bucket of fresh water even when it was exposed to salt water. But that was the only way it would survive the boat ride home and trip to the camera repair shop. I saw a Canon F1 and 55mm macro lens that came back into service after a salt water flooding.

Now if a camera is dunked, forget it. But now I'm wondering if that's so. If sensitive circuit boards can be saved, why not a camera? Perhaps the cost of complete disassembly

Pre-treating the equipment is a good preventative if it's going near the water. And if dunked, a fresh water flush is the first course. Possibly more than one flushing. Followed by something to displace water, such as isopropyl alcohol. And then drying it thoroughly in a container with a good dessicant like Drierite. It shouldn't be buried in Drierite, just sitting above it or the Drierite can be in vented containers.

Rice might work, but it's not as effective as a dessicant purpose-made for the task.

[Caustic]

z-axis , as I mentioned, my logic stems from processes with board manufacturing. Initial cleaning is usually alcohol based to remove contaminants such as biologicals, oils and materials that might dissolve into the distilled water. The distilled water is then used to remove traces left by the alcohol (alcohol always has some residue left).

There are some variations to this in manufacturing if components can be damaged by exposure, a material will react, or if in finishing a water soluble flux has been applied. I do not recall reading a research paper on the subject, just being informed and basic reasons.

In my experience with dessicants, pay special attention to what gases are released!
As for cameras, damage is hard to say, some of the caps do not like fluid and store huge voltages that may wipeout the os or memory chips. You could easily pay as much to recover it as to buy a new one, and you would never know when it might fail.

[Windbreaker]

Drierite doesn't spew contaminants. It's what labs use to dessicate percipitates for weighing, etc. At least that's what I recall from a chemistry class a LONG time ago. Not that I was a particularly good chem student. It was just a way to get access to other stuff that could make rockets.

Also, Drierite can be "recharged" in an oven. A one-pound bottle of it will last a long time. I recently gave some to a friend who use it to revive her cellphone that got wet.

I use it in small vented containers to keep the air dry in gasketed steel storage boxes for long-term storage of camera gear.

[z-axis]

Caustic, on 06 February 2012 - 07:16 AM, said:

z-axis , as I mentioned, my logic stems from processes with board manufacturing. Initial cleaning is usually alcohol based to remove contaminants such as biologicals, oils and materials that might dissolve into the distilled water. The distilled water is then used to remove traces left by the alcohol (alcohol always has some residue left).

There are some variations to this in manufacturing if components can be damaged by exposure, a material will react, or if in finishing a water soluble flux has been applied. I do not recall reading a research paper on the subject, just being informed and basic reasons.

In my experience with dessicants, pay special attention to what gases are released!
As for cameras, damage is hard to say, some of the caps do not like fluid and store huge voltages that may wipeout the os or memory chips. You could easily pay as much to recover it as to buy a new one, and you would never know when it might fail.

Very interesting! I have zero experience in your area of expertise. Perhaps we could work together to create an OP Recovery Kit, complete with water, alcohol, drierite, and a voodoo doll.   That combo just might work!

[z-axis]

Windbreaker, on 06 February 2012 - 09:27 AM, said:

Drierite doesn't spew contaminants. It's what labs use to dessicate percipitates for weighing, etc. At least that's what I recall from a chemistry class a LONG time ago. Not that I was a particularly good chem student. It was just a way to get access to other stuff that could make rockets.

Also, Drierite can be "recharged" in an oven. A one-pound bottle of it will last a long time. I recently gave some to a friend who use it to revive her cellphone that got wet.

I use it in small vented containers to keep the air dry in gasketed steel storage boxes for long-term storage of camera gear.

Yep I used Drierite a lot, but when you really wanna get stuff dry, you use molecular sieves. Those bad boys can suck a golf ball through a garden hose!

[Caustic]

Haha! z-axis!

I have no idea if one method is better than the other, I suspect the key aspect is to deactivate the galvanic effects of the salt water as soon as possible by whatever is handy. You will know soon enough if you need to take more action (couple hours to a couple days) just by visual inspection, worst case is a toss up between throwing it away and resoldering every component.