Sheet metal stress failure - center rock guard cover

[hhendrix]

I was going to guess you had a 1 ton truck and almost put in my original post. Your truck suspension and the 12K WD are waaaaaay to stiff for your trailer.

My post was based on my similar experience I had with a F350 and 1200# bars for my WD. I have a 27' front bedroom with the front compartment behind the propane tanks. Both lower corners of the compartment developed stress cracks. I read here from Andy at Inland Center (Where is he anyway? He was a major presence here) about too stiff suspension/WD systems destroying trailers. I switched to 600# bars and life was better for both truck and trailer.

[Mark of SJC]

Originally Posted by hhendrix

I was going to guess you had a 1 ton truck and almost put in my original post. Your truck suspension and the 12K WD are waaaaaay to stiff for your trailer.

My post was based on my similar experience I had with a F350 and 1200# bars for my WD. I have a 27' front bedroom with the front compartment behind the propane tanks. Both lower corners of the compartment developed stress cracks. I read here from Andy at Inland Center (Where is he anyway? He was a major presence here) about too stiff suspension/WD systems destroying trailers. I switched to 600# bars and life was better for both truck and trailer.

I had similar thoughts as well. Our trailer is identical to your 27' and we will be getting a F-250 shortly. Because even that suspension is stiff, we're going with a Blue Ox WD/Anti Sway coupled with a Air Safe Hitch (https://airsafehitches.com/receiver-hitch/) that provides a much smoother ride for both trailer and TV. This will give you an exact idea of the isolation this set up provides:

https://www.youtube.com/watch?v=HoXB...madicFisherman

.

I think this may solve your current (and future) issues with the trailer "being beaten to death" by transmission of the truck's stiff suspension. We've heard first hand accounts of "pre-Air Safe" - cabinets thrown open, contents on the floor, to "post-Air Safe" not a cabinet door thrown open, zero turmoil of anything inside of the trailer that was previously tossed around.

[Alumalemon]

Contrary to most people’s opinion, this is actually quite a common issue. This has happened to my 2012 Eddie Bauer on both sides and in my opinion is a design flaw. How could it conceivably be a good idea to attach these brackets to the thin aluminum skin only?? I have watched the way these guards flex when subjected to high winds in tow. No way the external skin only can withstand that over time without failure. Good luck on your repairs. Just had mine repaired and it cost $10K!!

[jaybauman]

Quick comment on the "truck is too big" comments. At Airstream tongue weights, the 350/3500 suspension is equivalent to the 250/2500 suspension. The 350/3500's extra leaf springs don't kick in until there is quite a heavy load on the truck. When I have my trailer hitched and my 3500HD truck fully loaded for camping, a quick inspection of my suspension shows I am nowhere near engaging the extra springs.

So why would a 250/2500 be just fine but a 350/3500 be too rough? I don't get it.

[Vitaver]

When two different metals meet, from my years in yachting, I remember that one of them will ‘loose’, therefore the use of sacrificial zincs. https://www.engineersedge.com/galvanic_capatability.htm
“ In simplest terms, corrosion happens when metal’s inherent properties begin to degrade. All metal, including the metal used in fasteners, holds electric potential. Metals have different types of electric potential, though. And when two metals interact with water, which is an electrolyte, a galvanic cell is created and an electric current begins to flow between the two metals. This low-energy galvanic flow begins to degrade one of the metals: the one with the higher electric potential, to be specific.

The higher-potential metals are known as “anodes,” and the anode metal’s atoms actually lose electrons to the lower-potential metal, known as the “cathode” metal. This transfer of electrons creates what we think of as rust in the higher-potential metal.

The farther apart two metals are on the electric potential spectrum, the more easily the higher-potential metal will corrode. For example, zinc, galvanized steel and magnesium are high on the potential spectrum, while silver, gold, zirconium, platinum and titanium are low on the potential spectrum.”

There is a paste we used whenever aluminum met SS, to protect the former. It was a different brand (at West Marine, where sailors live), but this may do it: “ NYSHIELD has minimal tension loss (even up to 150° C), exceptional chemical resistance, and adheres well to most substrates. Simply apply NYSHIELD uniformly to the steel fastener surfaces that contact dissimilar materials, and it works to shield and protect the least noble material.”

[ROBERT CROSS]

Originally Posted by H_Mark

. On tightening the machine screws for the piano hinge in place, mounting the center rock shield bolt through the shield top center hole required much flexing of the rock shield. It seems the hole is about 1/4" off center of the bolt such that the bolt is pulled toward the piano hinge.
Again thanks for the helpful comments.

You might try repairing/patch the torn panel and leave the bracket and mount off.
Replacing in kind will just apply the stress in the same place again.
If you find you need it because of a buffeting concern you could re-mount the bracket where the stress is less.

Is the hinge and end bracket of the shield both riveted to a rib?
Both are riveted to a rib on 'Cloudsplitter.



Bob
🇺🇸

[4taxabel]

On another note, when I pulled back the rock guards, there is a rather large black spot on one side of the trailer. Apparently from rubbing? What is the solution for that situation?

[The Cralls]

I had a similar issue. First I drilled some very small holes at the ends of the cracks and then I filled them in with the silver sealant ACYRL-R. The drill I used was a 1/32, just enough to remove the stress concentrator at the tip of the crack and small enough the ACYRL-R would fill it in nicely. I have not seen any new propagation of the cracks since. Our Airstream is a 2012 International Serenity and I noticed the cracks last summer.

[H_Mark]

Black spot under rock guard? Rubbing aluminum will create a black residue. Was some debris trapped there?

[H_Mark]

Originally Posted by Alumalemon

Contrary to most people’s opinion, this is actually quite a common issue. This has happened to my 2012 Eddie Bauer on both sides and in my opinion is a design flaw. How could it conceivably be a good idea to attach these brackets to the thin aluminum skin only?? I have watched the way these guards flex when subjected to high winds in tow. No way the external skin only can withstand that over time without failure. Good luck on your repairs. Just had mine repaired and it cost $10K!!

The repair shop plans to add two sheet metal layers fixed with adhesive behind the top center rock guard mount. One layer is supposed to span from the piano hinge to the top rear mount. Another item - the OEM rock guard mounts (piano hinge and three studs) are hard points, no flex. I asked about sandwiching the rock guard between two rubber washers for the three stud mounts. They thought that was a good idea. They will also set the top center rock guard mount such that there is no stress or pulling toward either side. In my case, re-attaching the rock required much pulling against the piano hinge to insert the OEM center stud into it's hole in the rock guard. This stretch and stress remained afterwards; furthermore, when I discoverd the center mount failure, the top three piano hinge screws were loose, the top screw the most.
Cause of failure - improperly aligned top center rock guard mount. Contributing factors - maybe hard point mounts without flex, maybe wind buffeting.

I don't know about this "too stiff" truck and load distributing hitch suggestion yet. I set up a LASER level on the side of the front hitch frame aimed rearward toward the trailer body. Marked vertical and horizontal with the trailer unhitched. Attached the trailer with the load balancing hitch to the truck. Both vertical/horizontal after-hitching LASER lines aligned with before-hitching perfectly. Perhaps this "too stiff" issue becomes a problem during driving over undulating pavement. Both the hitch manufacturer and a respected hitch vendor don't see that as an issue especially when trailer loaded hitch weight is 930lbs, not including hitch weight of 120 lbs and whatever weight is behind the truck rear wheels. 930+120=1050 which makes my current balancing hitch the correct choice per the mfg. Still I wonder about this since others have a different experience.

[Blomb]

we had this same problem on our 1999 Safari,we were getting water in before we noticed the problem. I cut a stainless steal blank electrical cover, formed it to fit the Airstream drilled 4 holes and put sikaflex all over the backside, and riveted in place. I did both sides to match, only one was cracked, and have had no trouble for 3 years. I did not find any other issues when I was making these repairs. I do check these areas every year to see if there are any other issues, and so far none.

[panamerican]

Originally Posted by Alumalemon

Contrary to most people’s opinion, this is actually quite a common issue. This has happened to my 2012 Eddie Bauer on both sides and in my opinion is a design flaw. How could it conceivably be a good idea to attach these brackets to the thin aluminum skin only?? I have watched the way these guards flex when subjected to high winds in tow. No way the external skin only can withstand that over time without failure. Good luck on your repairs. Just had mine repaired and it cost $10K!!

Just as a point of reference. Attached are two photos from around 2005 when they had the lower rock guards. As you can see from the photos there are reinforcement ribs in key areas in front. My guess is that with the taller rock guards, there is more to attach to than there was back in 2005, however, I do not feel that they simply bolt these to the skin alone given what I saw at the factory during production.

Originally Posted by jaybauman

So why would a 250/2500 be just fine but a 350/3500 be too rough? I don't get it.

I have a 2500 and it's still a pretty tough/rough riding suspension. I have the AirSafe hitch as well to counter that harsher ride. I personally think the truck is not as critical as the bars possibly being used. A 2500 or 3500 needs only the most modest of bars based on the fact that both 2500 and 3500 have more than ample capacity to carry the dead weight of the hitch (several variables also to consider). In my case I use between 600lb and 800lb bars depending on which coach I tow. With a 2500, I don't need 1000lb or 1200lb bars. I just need enough flex for the sway control to be effective and do just the ever most slight amount of hitch weight distribution to achieve that effect.

[Iowa Bumpa]

I have a 2016 - 27’ Flying Cloud. It’s been one thing after another with this unit. The upper middle support tore out a piece of the aluminum behind the rock guard. All the screws were loose and all of the fasteners on the non-hinge side have hollowed out to the point where I had to insert bigger washers to compensate. I am disgusted, to say the least. Called Airstream customer service and he had a button lip. According to the mechanics in the warranty dept. at the factory, Warren Buffet has instigated a production incentive. The more units they build in a day, the more money they make. They told me the quality is going down hill - fast! I just ordered a new 2021 FC to get rid of this lemon. Sure hope the new one was built in the middle of the week and not on Monday morning or late Friday afternoon. One would think that paying 90K for supposedly the best built trailer in the industry, things like this would not happen. Love the floor plans and the history and the folks who travel the bi-ways. But corporate and profits are really hurting the image of what Wally started. Sorry to vent, but I would like to ring someones neck, if you know what I mean!

[n2916s]

I believe that Mr. Buffett owns Forest River, not Thor or Airstream.

[Blischke]

We have a 2015 19' International and just noticed a similar problem on a recent trip to the southwest. In the short term, I have disconnected the rock guard from the middle support bracket while I figure out how to repair. Removing the support bracket and attaching a patch on the aluminum skin seems like the best option with, or without, reinstalling the support bracket.

Eric

[MoAir1965]

I have the exact same issue. Brand new FC on about the 4th trip. Questions: 1) is this warranty work?, 2) there is no AS dealer near me—is it possible to get AS warranty work done in a city with no AS dealer?

Here is the damage:

[jaybauman]

Originally Posted by MoAir1965

2) there is no AS dealer near me—is it possible to get AS warranty work done in a city with no AS dealer?

There are options available. Call Airstream customer service and explain your problem and your location. Depending on the issue, they have derogation authority to let you go elsewhere. It's a bit cumbersome, but I've had to go "out of network" for a few warranty repairs.

[MoAir1965]

Originally Posted by jaybauman

There are options available. Call Airstream customer service and explain your problem and your location. Depending on the issue, they have derogation authority to let you go elsewhere. It's a bit cumbersome, but I've had to go "out of network" for a few warranty repairs.

Thank you.

[Iowa Bumpa]

I had my metal/welder contact who also installs stainless steel countertops. The guy can do anything. He took a 4” x 4” patch and riveted on after installing the mounting flange. Good as new. However, the real problem is this: He said there is a design flaw in the piano hinge that holds the rock cover. It’s curved! There is no hinge that can work on a curve. They take a straight hinge and bend it to fit. The screws work loose on the very bottom and then then whole hinge wiggles the remaining screws loose. The wind current under the bottom further loosens the right side bolts, reaming out the hole until the whole rock guard which is only permanently fastened in the top middle starts vibrating and guess what happens next. If they had designers at Airstream that had a common sense/mechanical background, flaws like this would not happen. I could go on about the overhead sink cabinets coming loose or the curved sink cabinet doors that fall off. But hey, this thread is only about holes in our 100K travel trailers that are supposed to be the best built in the industry. Right?

[Rolind]

I’ve noticed that both my rock shields would distort, flex and vibrate when on the highway. The street side shield would distort so badly that it would contact the trailer and left and abrasion on the trailer. The vibrations were often very violent and seemed like a harmonic resonance, ie the Tacoma Narrows bridge collapse. I picked up a roll of adhesive 1” foam insulation from Home Depot and applied several strips to the trailer behind the rock shield and almost all of the vibration stopped. At least in my situation, this vibration almost certainly would have led to a failure of the trailer skin at the shield mounting brackets.