Date: Sat, 15 Aug 2009 10:10:51 -0700
Reply-To: Rocket J Squirrel <camping.elliott@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Rocket J Squirrel <camping.elliott@GMAIL.COM>
Subject: Re: Electronic Rustproofing?
In-Reply-To: <0a4701ca1dc7$700cb9a0$3400a8c0@tomrmkj2yanjy9>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Tom, as a geek, I do love reading an in-depth response to a technical
question. Many thanks for the info!
--
Mike "Rocket J Squirrel" Elliott
84 Westfalia: Mellow Yellow ("The Electrical Banana")
74 Utility Trailer. Ladybug Trailer, Inc., San Juan Capistrano
Bend, OR
KG6RCR
On 8/15/2009 9:42 AM Tom Hargrave wrote:
> Corrosion occurs when you have metal surfaces with positive ions and
> negative ions and those areas are bridged with a conductor (water or salt
> water) Surface rust is caused by positively charged metal surfaces being
> exposed to oxygen and it not the same as corrosion. Actually, surface rust
> can build up a barrier that will help to prevent corrosion. Aluminum and
> copper as well as quite a few other metals will do this as soon as they are
> exposed to air, so does stainless steel. So will mild and high carbon steel
> if given a chance - this the dark brown coating an items like carbon steel
> knives, the brown coating (called browning) on old handguns & long guns and
> on old steel antiques. Some of today's spray on "rust converters / stoppers"
> chemically build a brown oxide layer and if applied right, work well.
>
> The electronic Rustproofing devices work by keeping everything at a slight
> negative charge and the theory is that with no positively charged metal
> there will be no corrosion. I remember people trying to sell these in the
> 70s and even then those who were selling the units could prove they worked
> "in theory". The problem comes from that fact that we all already have one
> of these devices installed in every one of our cars!!!
>
> Let me explain.....
>
> Years ago car manufacturers noticed that car bodies with a positive ground
> electrical system would corrode much faster than car bodies with a negative
> ground electrical system. This is why all cars manufactured today have a
> negative ground electrical system. All of the positive ions gather on the
> positive side of the electrical system (the hot side) and all of the
> negative ions gather on the negative side of the electrical system (the
> ground side which also happens to be the car body). This is also why the
> surface of your copper wires turn dark so fast and why only the positive
> terminal of your battery corrodes!
>
> BTW, boats take a much more aggressive approach. They bond all of the metal
> parts together with copper wire then they run a wire to a sacrificial anode,
> usually zinc, below the water line. This guarantees that the anode has
> positive ions & everything else has negative ions, causing the anode to
> corrode away instead of the other metal parts.
>
> We could do the same thing with our cars but I don't think you want to be
> standing waste high in water. But VW and the other car companies did the
> next best thing. They started building cars in the 80s with steel panels
> coated with a sacrificial anode - it's called zinc plating. The problem is -
> steel is different than any other metal alloy. Steel has localized regions
> of positive and negative charged ions and body corrosion starts once the
> anode (the zinc plating) has been used up, even in a small area.
>
> And there are other issues with car bodies. Welding and folding plated steel
> damages the zinc coating. Plus, once seam areas get wet they tend to stay
> wet. This is why corrosion usually starts in seams - the zinc coating was
> damaged during manufacturing and / or was used up there first. The right
> answer is to repair those areas then protect them with a good undercoating
> that won't let oxygen (air) or moisture come in contact with the steel
> surface. Undercoating seams that have started to rust will only slow things
> down because you can't get the moisture out.
>
> Thanks,
> Tom Hargrave
> Our Web Sites:
> www.kegkits.com
> http://www.kegkits.com/JABF/
> www.stir-plate.com
> www.andyshotsauce.com
> 256-656-1924
>
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@GERRY.VANAGON.COM] On Behalf Of
> Max Wellhouse
> Sent: Saturday, August 15, 2009 9:12 AM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Electronic Rustproofing?
>
> Well, the title says it all. I was on the Subie Outback web page and
> saw this little gem. Apparently some dealers are selling electronic
> rustproofing for your car now. Can't confirm what country this was
> in, but a reply on the post was a guy from Austrailia fixin' to
> become a dealer for such stuff. To say the least, she got a lot of
> response saying it wouldn't work and the process was likened to the
> electronic(magnetic) fuel conditioners for sale
>
> So, I don't think I've seen this thread discussed on the Vanagon list
> so far, so have at it boys and girls!! Would be great if it did work.
>
> DM&FS
>
> Link provided by the Aussie
>
> http://www.couplertec.com.au/index.html
>
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