Log In | Register
Skip to main content
Topic: How to repair rust bubbles  (Read 1232 times) previous topic - next topic
0 Members and 5 Guests are viewing this topic.
How to repair rust bubbles
Hi gang.
Got an issues with rust bubbles appearing on the rear exterior wall on my 2002 31' LD.
During a more detailed inspection after purchase I noticed the rear window had been broken and repaired with a tinted sheet of Lexan plastic. This was not acceptable. I ordered a new window with frame from the mother ship. It was installed by Camping World. I asked the installer if he detected water damage. He said no. The new window was vacuum sealed. Attached are photos showing rust bubbles. A body shop inspected the problem and said they could repair.
What are your thoughts and suggestions?

Many thanks!
Mark
2002 30' IB

Re: How to repair rust bubbles
Reply #1
Looks like electrolysis which means you do indeed have moisture on the inside. There are many more knowledgeable forum members than me that can advise on repairs. But in my opinion, job one would be to ensure your roof is sealed. Eterna Bond tape is the DIY way to go. Check the Companion website for great tutorials on how to make that fix.


1998 Mid Bath

Re: How to repair rust bubbles
Reply #2
Rick has it right, it looks like electrolysis, caused usually by water leaks. Poor prep before painting could cause problems but they would have shown up years ago. Our 1983 LD had two spots that looked the same but were caused by the aluminum skin contacting staples, not the obvious choice here .

The paint can be sanded down and then prep aluminum with an etching primer, next the surface is cleaned again and the new paint is applied.

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: How to repair rust bubbles
Reply #3
Hi Mark;  Water is getting in at the top, maybe as high as the roof, more likely just above the window. (I've had issues with my local CW. Individual stores and workers are of course different.)     Water behind the aluminum, between the wood backing and aluminum causes the corrosion. The aluminum turns to a crumbly chalky white powder, a 'salt' of aluminum oxide and swells the paint. You might as well cut those bubbles of paint out.    Your first picture of the ladder support has a missing screw.  Just that size hole could let in a lot of water.  That the previous owner put in a plastic panel could be a sign that there were problems in that area.  Taking out a screw here and there can tell you if the water issue is widespread. The screw threads will be rusty, or may not be tight in sound wood.  Squirt some sealant into each hole before replacing the screws you've taken out.
   You didn't say if those bubbles showed up after the window was replaced. It is common RV practice to just use a double sided butyl rubber (gray goo) tape, screw in the screws and clean away what oozes out with a solvent.  That will work for about 10 years. If indeed the CW people didn't see any water staining on the window frame, then that water could be coming from the roof area.   I would expect corner 'end rot' below, near the bumper, if the water is entering near the roof.   Larry K. is having that issue now with his 2001.
   Keep us apprised with how your inspection/repairs go.      RonB
RonB (Bostick) living in San Diego
Original owner of "Bluebelle" a '99 TKB

Re: How to repair rust bubbles
Reply #4
Hi Ron-
The bubbles were present before installing the new window. That's actually what brought my attention to the window.
Do you think the water is between the paint and aluminum?

Mark
2002 30' IB

Re: How to repair rust bubbles
Reply #5
Hi Mark;  I do think the water is between the wood backing and the inside of the aluminum. The back of the aluminum isn't protected as far as I know. Just residual glue. I haven't torn anything apart on my LD. The water eats through the back of the aluminum where it puddles. My previous (not LD) motorhome had some spots before I sealed its roof. On those spots I chipped the aluminum out to bare aluminum and into the wood a little. I used Bondo to fix it and painted it. The key is to prevent more water intrusion. It will just eat out other spots.  RonB
RonB (Bostick) living in San Diego
Original owner of "Bluebelle" a '99 TKB

Re: How to repair rust bubbles
Reply #6
Thanks Ron!
I called the mother ship. They told me the same thing.
Well I know what I'll be doing this spring when the weather warms.

Mark
2002 30' IB

Re: How to repair rust bubbles
Reply #7
Somebody at the LD group this month mentioned that their previous Lazy Daze had an issue with what looked like bubbles in the aluminum, and was told by an RV tech that the cause was electrolysis due to a defective 110/12v converter unit leaking to ground. 

Replacing the converter resolved multiple electrical issues, whether or not it actually caused the electrolysis would be difficult to confirm but is an interesting theory.

Steve
2015 TK

Re: How to repair rust bubbles
Reply #8
Hi Steve TK; Lets see..... how to put that that theory to rest delicately...Utter nonsense!!!     RonB 
RonB (Bostick) living in San Diego
Original owner of "Bluebelle" a '99 TKB

Re: How to repair rust bubbles
Reply #9
After a second inspection I think my water issues are coming from the end caps. The roof has a good seal.
For a temporary fix, can I caulk the caps and wait until warmer weather? Could this trap moisture under the caps and cause more issues? Should I remove the bubbles, treat and prime?

Thanks!
Mark
2002 30' IB

Re: How to repair rust bubbles
Reply #10
Hi Mark;  The end caps are ABS plastic, and there shouldn't be any bubbles, except paint peeling off. There shouldn't be that either.  The bubbles are due to water behind the aluminum, causing electrolysis. That dissolves the aluminum and comes through the back of the paint layer.  Anything to stop the water penetration even 'stop gap' measures is good.  If the roof seals are good, in your year range, the tops of the windows need to be inspected and resealed.  This can let water in, which pools in the lower framing below the windows.
    I know that I've had water intrusion into my end caps at the bottom, where it was essentially open at the rear bumper.  I have sprayed sealer, paint and some under coating on the wood piece at the base of the bumper. That needs recoating every few years because of sand blasting from tires and street sand, gravel, etc. as the vehicle is being driven.    RonB
RonB (Bostick) living in San Diego
Original owner of "Bluebelle" a '99 TKB

Re: How to repair rust bubbles
Reply #11
Hi Ron-
Thanks  for replying to my question.
When I purchased my LD. I had to replace the rear window. Obviously the window at some point was replaced
had been broken and replaced with Lexan plexiglass. I purchased a new frame with glass from the mothership.
I had the new window installed by Camping World. How would you repair the bubbles. I may be able to make the repair but I don't have the experience or time to tear out and replace the aluminum.

Thanks
2002 30' IB

Re: How to repair rust bubbles
Reply #12
Hi Mark. Pictures of the issues would help me or others recommend any course of action. RonB
RonB (Bostick) living in San Diego
Original owner of "Bluebelle" a '99 TKB

Re: How to repair rust bubbles
Reply #13
Hi Ron.
I included photos with my original post. I'll post them again
2002 30' IB

Re: How to repair rust bubbles
Reply #14
Photos
2002 30' IB

Re: How to repair rust bubbles
Reply #15
window
2002 30' IB

Re: How to repair rust bubbles
Reply #16
Sorry Mark I didn't go back that far, but I see the pictures now. Definitely water getting into the back wall. It looks terrible around the top of the window.   Something as simple as a missing screw on the ladder support can let water in.  I personally don't let Camping World work on my LD. They are generally clueless about Lazy Daze construction. The one time I had them work on my first motorhome (not an LD), they ignored me when I gave them special instructions to drill a pilot hole for my A/C install. I put in OAK, western red in the ceiling, and the tech expected pine. So he used a self drilling screw in the exact location and broke off his screw.  He left it there, because it broke under the surface of the wood. Then he couldn't get three wires in romex (black white and bare copper ground) connected right.  Hot lead where the neutral went. Good thing I checked it.  I knew there was trouble when they put the A/C unit on the fork lift, got it half way up and dropped it on the concrete floor upside down. At my insistence (I walked out onto the floor area) they got me a different A/C unit, but they put the other one back in stock. I'm sure they didn't make a note on that unit that it had been dropped!  Of course the manager and employees are different at each store, but I have a long memory about 'stupid' employees.
   My first mh (non LD) had rot around the back window. I took it out and found that it had been installed upside down. The weep holes at the top let water in. No weep holes at the bottom kept it in. And termites also! Another story....  RonB
RonB (Bostick) living in San Diego
Original owner of "Bluebelle" a '99 TKB

Re: How to repair rust bubbles
Reply #17
I didn't have much of a choice who installed the window. I lived in Northern Minnesota. Driving to California was out of the question. Auto windows companies were clueless. Now, how would you address and repair the problem.

Thanks!
Mark
2002 30' IB

Re: How to repair rust bubbles
Reply #18
FYI- My insurance is combining out next week to inspect. I have full coverage, but I'm anxious they may try to get out of covering the damage.

Mark
2002 30' IB

Re: How to repair rust bubbles
Reply #19
Question:
Can I sand and treat the rust areas with a product designed to halt the rust from expanding?
Before I would treat the rust areas I would try to locate the source of the water leak.

Thanks!
2002 30' IB

Re: How to repair rust bubbles
Reply #20
Hi Mark;  Rust is iron oxide. Only iron and steel rust.  If you stop the water, the aluminum will stop corroding. Also an oxidizing event, that air gets everywhere. The white crumbly material is aluminum oxide. It won't spread if you keep it dry. Generally cut it back to sound aluminum. I'd rough up the wood underneath and put Bondo in the hole. Sand it down and paint it.  The aluminum moves around on the surface, expanding and contracting with temperature, so a fixed hole may not stay fixed.  If it is a large enough hole, get a piece of thin bare aluminum and slide it in behind the hole and Bondo to that. It may shift with the sheet and stay looking fixed. Larry and others may have more experience with this type of repair. My only experience was with a 'quarter' sized hole on my old (non LD) motothome.   RonB
     Something like this. Hope you took 'shop' classes in high school.  Order Aluminum Sample Pack 6061-Sheet Online
RonB (Bostick) living in San Diego
Original owner of "Bluebelle" a '99 TKB

Re: How to repair rust bubbles
Reply #21
Thanks Ron!
I was just looking for a temporary fix until warmer weather allows me to tackle the damage.
I'm not an auto body guy so I may have a pro make the repairs.

Thanks!
Mark
2002 30' IB

Re: How to repair rust bubbles
Reply #22
Hi Mark.  I don't know what your expertise level is.  Don't use any silicone sealer.  Dap acrylic will seal for now, and be easy to remove. Eternabond is hard to work with, hard to remove, and meant for permanent repairs. Don't use that either. Same with 3M 4200, 5200 sealant.    White duct tape applied carefully over the bubbles. It will make it worse if it traps more water in the wall, but if dry can protect it temporarily.
   The fact that you had a plastic back window was a bad sign to start with.   Auto body repair people also aren't the best. They work with cars, and your motorhome isn't a car.  No steel, and wood isn't what they are used to fixing.  Lazy Dazes are peculiar, almost one of a kind anymore. OK Thor and others do use wood framing, but not the same way as LD.   You need to find an RV repair facility, that can fix water, roof leak and other location leaks.  You'll have time to investigate potential repair locations in the next month or so.  RonB
RonB (Bostick) living in San Diego
Original owner of "Bluebelle" a '99 TKB

Re: How to repair rust bubbles
Reply #23
Many thanks Ron!

Mark
2002 30' IB

Re: How to repair rust bubbles
Reply #24
I would open each bubble and clean away any of the white oxides, lightly scraping it down to the bare metal. A dental tool works well. Make sure the holes do not fully penetrate the aluminum skin. Look for red oxides or rust, a sign there is contact with a ferrous metal behind the sheet aluminum.
Bare aluminum needs to be etched for good bonding. Vinegar works fine, it isn't fast so let it sit a while before cleaning with fresh water. Next is the paint.
You are lucky to have all the bubbles in areas painted white. Your rig and most other LDs are painted Oxford White, from Ford.
Oxford White is widely available in touch-up bottles or spray cans.
The touch-up bottles should work best, allowing you to build up layers.

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