Zinc Screw = Sacrificial Anode?

[PackRat]

I'm reading how those zinc screws are being eaten away on some campers and I also read that the metal skin is often a part of the grounding system on some campers....

Not being an electrician myself, the question is this: Are those zinc screws somehow acting as sacrificial anodes on these metal skinned campers? If so then insuring that the camper is not being used to ground anything such as cab running lights or interior lights which may be "hot" all the time the solution?

I know they attach sacrificial anodes to ships that are eaten away and need to be replaced from time to time so that is what got me to thinking about this.

 

[ntsqd]

It is unfortunate that some (most?) clearance light assemblies do not provide for a ground wire connection. When I rewired our camper I bought a fuse block with a ground buss included and ran a dedicated ground wire for each circuit. It does not have any vehicle operation related lights on it.

If you are seeing erosion of plated screws one of two mechanisms is at work. There is either stray current being conducted thru those screws or moisture is able to penetrate the joint and electrolysis is eating away at them. Seal the joints and check for poor or non-existing grounding.

 

[CougarCouple]

Hello NTSQD
that would be a good idea to use this information to keep in mind and use as preventative Maintence. Just looking and keeping an eye on things.
Thanks Russ

 

[Squatch]

In my Eagle camper there is a small ground plate screwed to the roof frame. It's inside the opening where the solar wires go through under the front lifting board. When I checked it one of the screws was almost falling out and the other was very loose. I tightened it up and all is good. Left loose it would have had a lot of potential to cause electrical and electrolysis issues.