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Topic: Aluminum skins/electrolysis repair (split from Re: Hello Everyone!) (Read 174 times) previous topic - next topic - Topic derived from Hello Everyone!
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Aluminum skins/electrolysis repair (split from Re: Hello Everyone!)
Quote from: RonB  - 
Hi Will; A Diesel engine! 1999 was the sweet spot year for that engine.  A friend has a '99 F350 crew cab that is just 3" shorter than my motorhome.  Expected to last up to 400,000 miles, I'm curious how many miles you have on your Lazy Daze.  I also have a '99, but the E350 chassis and V10.  Welcome to the FOLD! (Fellowship Of Lazy Daze). RonB

Hey Ron,

Do you know if the aluminum skins are completely flat or do they have a step pressed on the upper edge to create an overlap? My LD has a several electrolysis bubbles that were never repaired. I'm trying g to determine if a complete skin replacement would be better.

-Will
1999 MB, 7.3L PowerStroke
Re: Aluminum skins/electrolysis repair (split from Re: Hello Everyone!)
Reply #1 –
The aluminum sheets have interlock bends on the top and bottom.
We can provide better advice with photos of the problem areas.

Larry
Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze
Re: Aluminum skins/electrolysis repair (split from Re: Hello Everyone!)
Reply #2 –
Quote from: Larry W  - 
The aluminum sheets have interlock bends on the top and bottom.
We can provide better advice with photos of the problem areas.

Larry

That's what I thought. I'll be able to snap some really good photos in the next few days to show the FOLD. Thanks again.

-Will
1999 MB, 7.3L PowerStroke
Re: Aluminum skins/electrolysis repair (split from Re: Hello Everyone!)
Reply #3 –
Hey Larry,

Here's some photos of the electrolysis that needs treatment. There's 2 really bad spots. For reference, the last picture is what I am thinking of doing when my LD gets painted.
1999 MB, 7.3L PowerStroke
Re: Aluminum skins/electrolysis repair (split from Re: Hello Everyone!)
Reply #4 –

I suspect the rear window is leaking and is causing the damage.
Have you found any rot inside the rear wall, which is common with rear window leaks?
I would not tear the rear wall apart unless the wood framing is rotted, the sheet metal can be repaired or sealed without disassembly.
Taking the rear wall apart is a challenging job even for the experienced. The rear end caps need to be removed to access the rear aluminum panels; the caps can be badly damaged or destroyed while attempting to remove them. Even if new caps can be found, they will be expensive.

I would remove the rear ladder and sand away the corrosion off the sheet aluminum to see how deep the damage is. Minor holes can be filled, and more badly damaged sections can be covered with small pieces of sheet aluminum. When painted the repairs will blend in. This will not be a "like new" appearance but will save you a huge amount of work and expense.

The rear window may need removal to seal the window's perimeter and to reseal the three glass pieces with a clear silicone sealant made for windows... the only silicone I use in the coach.
Every older MB or T/K, the models with the three-piece rear window, I have worked on had evidence of water leakage between the glass and rubber seal. The rubber seals shrink as they age, sort of like people.
Amazon.com: Permatex 81730 Flowable Silicone Windshield and Glass Sealer,...

Larry
 

As an Amazon Associate Lazy Daze Owners' Group earns from qualifying purchases.
Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze
Re: Aluminum skins/electrolysis repair (split from Re: Hello Everyone!)
Reply #5 –
Hey Larry,

When I checked out the coach I didn’t find any evidence of wood rot on the inside. I want to make sure I get to the repairs before the rain comes to SoCal this winter.
1999 MB, 7.3L PowerStroke
Re: Aluminum skins/electrolysis repair (split from Re: Hello Everyone!)
Reply #6 –
Quote from: Dtbback  - 

When I checked out the coach I didn’t find any evidence of wood rot on the inside. I want to make sure I get to the repairs before the rain comes to SoCal this winter.

The rear window is probably the culprit of the leaks and corrosion. It’s good that there is no damaged wood observable.
Waterproofing everything before the winter is your primary concern, we received a lot of rain over the last two years.

The roof seams should be resealed if it has not been done already.
Check all the window seals, the Factory sealant shrinks with age and forms concave depressions along the top and sides of the window that can hold water.
Window and end caps are the most common sources of leaks.
Window and seam sealing | Flickr
Roof seam reseal | Flickr

The rear bumper is going to be a project. The top piece needs to be cut off, and a new piece of heavy sheet metal must be bent to replace the rusted top.
While the top piece is welded in many spots, the overlapping gaps are not sealed and allow moisture to enter, causing rust.
There's a good chance your rig spent a lot of time at the beach and was not washed afterward. Salt is evil.
The bumper’s vertical bolts are crucial to the structural strength of the bumper, do not neglect to install them if you plan on towing.

Larry
Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze
Re: Aluminum skins/electrolysis repair (split from Re: Hello Everyone!)
Reply #7 –
Quote from: Dtbback  - 
To be honest I am little scared of what I'll find once I start probing. Haha. I took of the "spare tire cover" hoping I lucked out but I didn't. I did find this (see pics below) and I am not happy about it.

If the interior wall, opposite of the seam seems solid, clean and reseal the seam with polyurethane and worry about the known issues. A layer of clear tape or Eternabond Tape would also seal it.
Your LD is 25 years old, expect to find all sorts of little problems. The repairs and upgrades will continue until the day you sell it or die. It’s part of the journey.

Larry

Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze
Re: Aluminum skins/electrolysis repair (split from Re: Hello Everyone!)
Reply #8 –
It looks like the interior is all good. I am going to do as you suggested and seal everything up and eternabond that seam. What is your opinion on using eternabond on the roof end caps?
1999 MB, 7.3L PowerStroke
Re: Aluminum skins/electrolysis repair (split from Re: Hello Everyone!)
Reply #9 –
Quote from: Dtbback  - 
It looks like the interior is all good. I am going to do as you suggested and seal everything up and eternabond that seam. What is your opinion on using Eternabond on the roof end caps?


Eternabod Tape works well on the roof seam. Used on the end caps would work but it wouldn’t look good.
I use short pieces of Eternabond Tape to cover the small gaps in the end caps on the rear.

Sealing the end caps with polyurethane is my preference, adding stainless steel sheet metal screws to pull the caps into position when they refuse to lay flat.
Searching the archives will provide many postings on this subject.

Larry
Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze
Re: Aluminum skins/electrolysis repair (split from Re: Hello Everyone!)
Reply #10 –
Quote from: Dtbback  - 
How many tubes of the 3M 5200 should I need for the roof and end caps?
How many tubes of the window sealant you recommended in your other posts?
Should 40’ of 4” Eernabond be sufficient to seal the roof caps and vents?


3M Fast Cure comes in 1oz, 3oz, and 10oz tubes. It should be used within a few days of opening a tube.
I use all three sizes, the 1oz packets are perfect for quick, small projects. 3oz containers are good for a couple of windows or end caps. The 10oz tube are the most economical way to go when you need a lot of it over a shorter period of time.
The size of the container should depend on how much you plan on using within a few days times.

3M 5200 Fast Cure is also available in a slow cure version, 3M 5200. It takes several days for it to skim over and can get messy from dust, leaves, and other aerial debris. It’s best to avoid it.

Each sealing project takes time, usually a whole lot longer than what you estimate or seems reasonable.
Cleaning, prepping, and sealing the roof seam is a full-day job, applying the tape is easier with a helper.
Window and end cap prep are time consumptive, requiring extensive cleaning and taping before application of the sealant.

The clean and prepped roof seam uses only a few ounces to seal off any exposed screw heads before covering the whole seam with Eternabond Tape.
A Mid-Bath needs two 50’ rolls of Eternabond for the roof seams, with double strips across the front seam.
The tape is not used on the vents unless the vents are new, Eternabond does not stick well to the old sealant on the vents. The true seal on a vent is between the bottom of the vent and the roof. The sealant on top and to the sides of the vent does little other than protect the plastic from UV.
The sealant around the vents can be overcoated with polyurethane or non-sagging Dicor.  Dicor is much cheaper for overcoating.
If using Eternabond to seal the end caps, you will have to measure them for the amount needed, I have never sealed an end cap this way, instead, using polyurethane.

5200 is expensive and I hate to tell you to buy a certain amount it and have it be too much or too little. It is readily available online, buy it as you need it, there is a good chance these projects will not happen overnight.

Larry


Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze
Re: Aluminum skins/electrolysis repair (split from Re: Hello Everyone!)
Reply #11 –
Larry,

Thank you that is great advice. I only plan to use enternabond on the roof seams. I plan to use the 3M 5200 on the end caps, using your method. Since I am replacing all the roof vents I was planning on sealing them with eternabond, but if they ever need to be replaced I am starting to think Dicor lap sealant will be the better choice.
1999 MB, 7.3L PowerStroke
Re: Aluminum skins/electrolysis repair (split from Re: Hello Everyone!)
Reply #12 –
Quote from: Dtbback  - 
Larry,

Thank you that is great advice. I only plan to use Eternabond on the roof seams. I plan to use the 3M 5200 on the end caps, using your method. Since I am replacing all the roof vents I was planning on sealing them with eternabond, but if they ever need to be replaced I am starting to think Dicor lap sealant will be the better choice.

Has the roof ever been resealed? No matter, if it were mine,I would remove all the old seam sealant using a vibratory tool with a sharpened blade.
https://www.homedepot.com/p/Milwaukee-2-in-Stainless-Steel-Universal-Fit-Rigid-Flex-Scraper-Multi-Tool-Oscillating-Blade-Kit-2-Piece-49-25-2202/313845553

With the correct tool, the old sealant can be removed in an hour or two.
I used 5200 to lightly fill the center of the seam and then apply the tape over it. I used this method on several dozen of these jobs without any complaints or comebacks.




Glue the new vents to the roof with polyurethane, it is the manufacturer's way of installing a vent and will be easier to maintain in the future. A vibratory tool would be useful in removing the old vents and sealant.
Done right, you should never have to worry about the vents again.

Larry
Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze
 
Re: Aluminum skins/electrolysis repair (split from Re: Hello Everyone!)
Reply #13 –

Hey Larry,

I think I read that you painted any exposed aluminum after scraping with the vibratory tool. What paint did you use?
1999 MB, 7.3L PowerStroke
Re: Aluminum skins/electrolysis repair (split from Re: Hello Everyone!)
Reply #14 –

Larry,

Do you use lap sealant at all or just the 3M 5200? I have butyl tape for seating my new vent fans and was planning on running a bead of 3M 5200 around the edge and into the screw holes. I was thinking of covering the screw heads with dabs of 3M 5200 vs slathering on the Dicor lap sealant. I even considered using these (see link below) with a some 5200 underneath and inside the snap cap. Do you think it would be a waste of time?

Hotop 100 Pieces Hinged Screw Cover Caps Plastic Shutter Screw Caps Fold Screw Snap Covers Washer Flip Tops (White,Medium) Amazon.com: Hotop 100 Pieces Hinged Screw Cover Caps Plastic Shutter Screw...

As an Amazon Associate Lazy Daze Owners' Group earns from qualifying purchases.
1999 MB, 7.3L PowerStroke