×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Prevent Corrosion

Prevent Corrosion

Prevent Corrosion

(OP)
Does anyone think that it would work to attach bonded sacrificial anodes to a car to prevent body rust?  

RE: Prevent Corrosion

Would there be some type of electrical connection through the bonding area?  Most adhesives are poor conductors...

RE: Prevent Corrosion

(OP)
I'm sorry.  That's what I meant by "bonded".  Either connected to the frame and body using "bonding" straps or physically affixed.

RE: Prevent Corrosion

I thought thats what Galvanneal was for?

RE: Prevent Corrosion

Are you talking about body pannels or frame members?

RE: Prevent Corrosion

(OP)
Both.  

RE: Prevent Corrosion

You could attach an anode to the frame of the vehicle and that would provide you with some corrosion resistance.  However, you would have to attach the anode in several locations around the frame to provide any real protection.  Also you would have to "break the seal" of the corrosion protection that is already applied to your frame.  I don't know if it would work for body panels because of surface issues.  Most automotive paint finishes are good enough as is.  You might be able to attach anodes in older cars where rust is beginning to show, but again you would have to put the anodes in several different locations.

RE: Prevent Corrosion

Years ago I read something about an active electrical system which was supposed to completely prevent corrosion at the molecular level.  Haven't heard anything in at least a decade. Either quack science or suppressed technology.

RE: Prevent Corrosion

The following is a quote from Corrosion Doctors regarding those systems: "Countries like Canada and the U.S.A. have actually got court orders to stop these products from being sold - simply because they don't work."
http://www.corrosion-doctors.org/Car/Frames.htm

RE: Prevent Corrosion

Sacrificial anodes are all over your car already.  Galvaneel (like NickE mentioned) is a zinc layer that is on any good car body (I won't mention the names of the companies that don't use it!)

For the sacrficial anode to work, you need ELECTRICAL connection between your anode and the part you're protecting.  (Don't mount it to underbody PVC!)

Also, be mindful of whatever you use to strap it on.  If it's metal, it will also corrode! Some plastics don't hold up well to temperature changes.

The most common sacrificial anode used in the automotive industry is zinc (hot dipped, zinc plating, galvaneel, etc.  

Be careful not to create any crevice corrosion cells.

In the end, I think you might have a fun project, but I think you'll be disappointed if you do a Cost/Benefit analysis.

RE: Prevent Corrosion

This is a regular topic for discussion by the non-engineers on this site,  but invariably the conclusion is the same:  it doesn't work.

RE: Prevent Corrosion

It doesn't work because an anode must have an electrolytic solution of some kind to work, in other words water.  This provides a path from the anode to the metal being protected (the cathode).  It's a simple DC circuit.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources