Electrical Current Does Prevent Corrosion?

[T.Jackson]

I think many people are sceptically about the thought of electrical current being used to prevent rust. Until recently I was one of them. A few months back, after digging out half a dozen or so rather large printed circuit boards that I had in storage for almost 10yrs, arcade game boards that were working perfectly before they went into storage now ceased to work! On quick inspection I found lots and lots of corrosion!

Ironically, during the course of those 10yrs I took one of them out periodically, say every couple of months or so, and fired it up! I ran a short dose of electrical current through it and then placed it back in storage right along side of the others. Guess what? -- it's the only one that didn't have any rust and as a result still works! So there you have it, 6 boards that are all dead because of corrosion and 1 board that's in the same condition as it was 10yrs ago.

Gotta make you wonder -- maybe the long debated claim of electrical rust prevention isn't all that 'hocus-pocus' after all...

[skimask]

Gotta make you wonder -- maybe the long debated claim of electrical rust prevention isn't all that 'hocus-pocus' after all...

I've got an upper control arm for a '74 Chevy Malibu sitting out in the garage right now, in a plastic tub full of water with a little bit of 'Arm & Hammer' washing soda mixed in. The negative clamp of a 12v/10amp battery charger is connected to the control arm, the positive clamp of the charger is connected to a steel rod (standard concrete rebar) in the water.
The rust is 'boiling' off the part as I type. Another day or so and it should be rust free and ready for paint.
I've already done this to the both lower control arms, the other upper control arm, the car's original battery tray (which after de-rusting had to be throw out...not enough solid metal left!), upper and lower radiator supports, and numerous other bolts, nuts, pieces/parts throughout the vehicle.
It's not rust prevention...but it sure as heck is rust removal...

And...to add a bit onto this (only because a bunch of other people I've told about this think it's the wonder cure for rust)...
...NO...it does NOT replace the metal with brand new metal
...NO...it does NOT convert the rust to usable metal
All it does is cause the rust (the actual iron oxide) to liberate from the steel connected to the negative terminal to migrate to the steel connected to the positive terminal.The rebar gets rusted by the process and I have to scrape it off every once in awhile, clean it up, or throw it out. But it's rebar and it's cheap.

[Luciano]

Hi Trent,

Were all the board manufactured using the same technique?
Same day, same production line, same solder, same protection
against corrosion, same components, same ..., same....?

Best regards,

Luciano

[T.Jackson]

Hi Trent,

Were all the board manufactured using the same technique?
Same day, same production line, same solder, same protection
against corrosion, same components, same ..., same....?

Best regards,

Luciano

Hi Luciano,

That's interesting that you ask that, because all of the rusted boards were high quality Japanese made (circa 1990) but the one that's still alive (the one I periodically fired up) was made in Korea (circa 1983!) using very cheap components mounted on what appeared to be a second class board compared to the others in my opinion. So there's even more proof!, and more reason not to judge something from its price tag.

Best regards,

Trent

[mackrackit]

A good stiff brush might bring the boards back to life, I will bet that rust is not the only problem. Tin Whiskers.

Gotta make you wonder -- maybe the long debated claim of electrical rust prevention isn't all that 'hocus-pocus' after all...

Should not be a debate when it is basic chemistry, or electro chemistry.

It is not so much from forcing a current through to prevent corrosion as it is more of giving the charge between dissimilar metal a path to flow to.

Look up underground piping. Here in the US it is even in the building codes for gas stations as an example. The steel piping is required to be grounded in certain places with an anode in other places. The layout of the job determines the placement.

The same applies to water tanks if they are not lined with a coating of some sort or a bladder.

So when you power a board a path is created from the positive potential to the negative potential.

The example skimask gave shows how a forcing of current effects things, more along the line of electroplating, ( in his case as he said, he is not plating ) but it is still working on the theory of ionic exchange. I say theory because we currently use stuff from Dalton, but we may find that Keely is also correct. There is something to debate

[T.Jackson]

A good stiff brush might bring the boards back to life, I will bet that rust is not the only problem. Tin Whiskers.
Should not be a debate when it is basic chemistry, or electro chemistry.

Beyond economical repair as I like to put it. On a few of them the corrosion had set in so bad that the pins on some of the ics just fell off as soon as I removed them from their sockets. I know of one person who has a b.sci degree and publicizes that electronic rust prevention for cars is hoax. So I can't agree that it comes down to basic chemistry unfortunately.