electrolosis 2006 lance 915 alum?

[petoworx]

hello all, just took cover off camper and lo and behold on both "wings " i see corrosion/ bubbles on the alum siding??? i start digging and find the aluminum is just discentergrated , wood behind is fine.battery was removed all winter and nothing was running, unit unplugged,has anyone had or heard of this type of problem before? could it be electrolosis? any thoughts / ideas apprieciated. thanks ,pete

[kohldad]

I think it has more to do with all the contaminates and road salt than anything else. Some reasons the aluminum disintegrates quickly. First, the aluminum used in the wings is extremely thin. Second, the aluminum isn't painted which adds a lot of protection from the elements. The aluminum is just relying on the nature protection layer which doesn't work well against all of the road spray.

Better than an anode, clean the aluminum and paint it before installing. If you want an even extra layer of protection, take it to a fabricator shop that routinely deals in aluminum and have it irradiated/anodized which will chemically convert the surface to a thicker and tougher protection layer. Then it can be painted.

[NRALIFR]

I can't see an anode doing much good at this point. Even if you were able to stop the siding from corroding any worse, you would still have wood underneath that is likely rotting. I would pull some of the siding off and see what's going on, and make plans to fix it before it gets much worse.

:):)

[petoworx]

thanks guys ! ill check the jacks tonite and ill have to replace the siding on the wings. the wood was dry under the siding areas from what i saw. do you think it would do any good to install an anode to see if it stops and/or gets worse ? tahnks pete

[NRALIFR]

I've never liked using the word "electrolysis" to describe the type of corrosion you're describing. I hear it used a lot when what is really meant is "electrolytic corrosion". Electrolysis is simply the electrochemical process that might have caused the damage you see. When referring to a corroded item (usually aluminum) both terms are often used to mean the same thing. The terms do have one thing in common though, and that's they both require an externally applied electric current to drive the process. Since the camper was unplugged, and the battery was removed, you can probably rule that out.

What you are probably seeing is galvanic, or "dissimilar metals" corrosion. The screws and staples used in building your camper are not aluminum, and may be what is behind the disintegration of the aluminum siding. One other component is required though: moisture. Without the electrolyte (moisture), the corrosion will not take place. It could be as little as a humid environment causing some condensation, or as much as an active leak from a failed caulk seal. Either way, there is probably some moisture behind the skin that's worked its way in and has soaked the wood and insulation behind the skin.

It's pretty common on truck campers to see rot and corrosion in the wing area. I just had to replace mine about a year ago, and many other members have done the same. Lance will sell you or your dealer the materials needed to repair it. You can also source the materials and fabricate it all yourself. I've seen it done both ways on the forum with good results.

:):)

[Cannon_George]

Aluminum is considered less "noble" than steel, and if in direct contact with carbon steel will act as an anode, sacrificing itself in order to protect the steel (cathode). You eliminated the other potential cause (stray currents) by removing battery/shore power. The process is exacerbated by the presence of moisture, which helps act as a conductor.

I'm wondering do the steel jack legs show corrosion? Were they in contact with the ground, and exposed to water? If so, the aluminum may have been doing its best (as an anode) to protect the steel legs against corrosion.

I've heard of this happening to small aluminum boats in covered storage (in direct contact with steel storage racks) but never to a camper.