interior wall corrosion?

[60traveler]

One thing leads to another...
We have gutted the interior of our 1960 Traveler so that we can replace all the plumbing and lay a new cork floor. While scrubbing down the walls yesterday, I noticed that there are small areas on the interior aluminum skin that have some corrosion damage. Most of the damaged areas are on the bottom of the wall, butting the floor...probably water damage from the busted water pipes (hence the new plumbing job).
The damage is variable; the damaged areas are small but in some places the corrosion has eaten through the skin.
What to do? Repair? Patch? Product advice?
We'll try to post a picture soon...
Martha and Stacia

[59toaster]

What may be happening is a combinations of things. There is a form of corrosion called electrolisis (sp). WHat happens is two dissimulare metals can have an adverse reaction when touching. An electrical charge can cause this to happen. Moisture between the two can also cause this.
One of the compenents of a airstream's structure is a "U-Channel. It sits on the permiter of the floor and the rest of the body work attaches to it. The U-Channel is steel. It's possble some moisted like you though could have caused this to happen.


As to a fix....Well the intterior pannels at the floor are flat so making a new one would not be difficult. Zolotone is still available so if the area is exposed you could match it up. I would consider pulling the pannel where you have the worst problem and taking a peak at the u-channel.

I know on my unit I have a couple feet that I will have to fabricate where I have som long term water problems. I wouldn't freak out if you find a problem it can be remidied and if it is very localised it may not be causeing any structural problems and a little sheet metal or aluminum you could make a repair of the u-channel by riviting it on the vertical and some short wood screws on the horizontal through the to wood floor.

[74Argosy24MH]

If the corrosion is relatively localized you can probably patch it. If it is bad I would replace the panel(s), the inner skin is an important part of the strength of the trailer. They are pretty flat, but are a 3 dimensional curve. If you remove it in one piece you can use for a template to cut the new panel.

Eric, a question. My motorhome lower channel is aluminum, are you sure the channel on the trailers is steel? I know from talking to a guy who did a body off floor repair that the channels are shaped differently, never thought to ask what they were made of.

John

[59toaster]

Originally posted by 74Argosy24MH
If the corrosion is relatively localized you can probably patch it. If it is bad I would replace the panel(s), the inner skin is an important part of the strength of the trailer. They are pretty flat, but are a 3 dimensional curve. If you remove it in one piece you can use for a template to cut the new panel.

Eric, a question. My motorhome lower channel is aluminum, are you sure the channel on the trailers is steel? I know from talking to a guy who did a body off floor repair that the channels are shaped differently, never thought to ask what they were made of.

John

It's steel on the older ones like his and mine. I have put my fingers through a rusted through hole on mine. Last 4ft of my floor on the curb side is a total loss. That's under the bath on mine and there has been a long term leak there that my Father-in-law was un aware of. I have holes from below and a part of the bell pan is corroded away. I can look right up under the riser that the toilet and blackwater tank is on.
I am going to have to make a templet of the curve in that area and fabricate a new section in that area.

[Pahaska]

I'm pretty sure that the floor channel is aluminum, at least on current build. I can see mine at one place under the bathroom and it is certainly aluminum.

[Pahaska]

I'll defer to 59toaster's firsthand knowledge. Apparently, we were composing out posts simultaneously.

[74Argosy24MH]

It's steel on the older ones like his and mine

Interesting. I would replace it with aluminum for sure. I am suprised AS made it like that in the first place.

John

[geof]

.....several epoxys on the market will stick to the aluminum and be stronger than origional....a section of my floor channel was damaged by the PO trying to do-I know no what?-maybe drill a hole for some reason?-who knows?....anyway I cleaned the area wih a pressure washer and sand blasted the ajoining aluminum clean and blew out the dust and sand....made a channel with wood and used a piece of aluminum rod for a reinforcement bar....poured in the epoxy and by morning it was hard and more perminant than concrete....geof in Cincinnati

[60traveler]

i don't think our corrosion is coming from the frame or u-channels. from looking at pictures before we gutted the trailer, the damaged areas are located (1) where there were wooden supports for the gaucho that were totally wet and (2) where the original cooper water pipes had either busted or leaked.
so it appears that the damage originated from the interior and from water. in a couple of spots, there are small pieces of aluminum flecking off...about the size of a pencil eraser. does this warrant panel replacement or can we spot repair it with something like epoxy?

[geof]

....one word....EPOXY....tape the outside with duct tape-clean and rough up the surface on the interior and spread the epoxy and cover with duct tape...let dry for 24 hours....lightly sand the exterior to match....and your done....geof-near Cincinnati

[Pahaska]

Originally posted by geof
....one word....EPOXY....tape the outside with duct tape-clean and rough up the surface on the interior and spread the epoxy and cover with duct tape...let dry for 24 hours....lightly sand the exterior to match....and your done....geof-near Cincinnati

A layer of epoxy alone isn't terribly strong. If I were going to use epoxy in this manner, I would lay a layer of light fiberglass cloth in the epoxy and wet it well. Most larger hobby shops carry light fiberglass cloth for models. The minimal extra thickness is a low price to pay for the added strength.

[59toaster]

Originally posted by 60traveler
i don't think our corrosion is coming from the frame or u-channels. from looking at pictures before we gutted the trailer, the damaged areas are located (1) where there were wooden supports for the gaucho that were totally wet and (2) where the original cooper water pipes had either busted or leaked.
so it appears that the damage originated from the interior and from water. in a couple of spots, there are small pieces of aluminum flecking off...about the size of a pencil eraser. does this warrant panel replacement or can we spot repair it with something like epoxy?

If it's just surface an not all the way through then for the minnor areas you might be able to sand it smooth. Then paint over it.
If it has deep pitting then a filler could be used. You would still want to sand it to get the corrosion out. The sanding also gives a little texture to the surface so the filler will adhear to it better. Then a filler like Bondo or even EPPOXY filler Could be used then sand smooth and paint.

[geof]

John....the stuff I use is plumbers epoxy...no need for cloth...it's gray in color and ya got to mix the two sticks together-it's not in a tube...it kinda sets a little softer when mixed because of the heat and you can move it around a little with a putty knife or stick...when it sets up is is a little flexible to some extent-not much depending on thickness....if flexing is an issue I would fill any panel voids with spray can foam and re fasten the panel quickly if your working form the back[inside]...or fill the panel with Bondo for more compressive strength....when I re-insulated my trailer I used spray can foam and sheets of R-MAX polyisocynate foam board for a R-value of 14.....now I only use my A/C and heat at less tha 50% capacity....the skin is harder on the outside-whether hail will dent it I have no idea-but I don't want to test it out.....geof-near Cincinnati