Aluminum panels expanded and contracting???

[SL4BLLT]

Here's a question for someone of the engineering mindset type of folks, that have me generating this.

Over this last winter we had some repairs done to the 1972 31 foot International. We had three front panels replaced, 22,10 and 12 (top center, curbside upper, curbside with spot light) I may not have stated the numbers correctly and the three Vista windows. The work was done by a dealer and done nicely.
For the last three months we have had the A/S down on the North Carolina Coast where the temps have been in the high 90's with heat indices up to 115 degrees at time. We use the AS on the weekends, so it sits under a few trees attempting to stay cool until we get there and turn on the AC and normally get it to about 78 degrees.

This last week after driving through massive downpours of over 2 inches of rain and hour we relocated the AS to the mountains of NC at about 4000 feet. We go from sea level to 4000 feet ( Blue Ridge) and love the temps! Now here's the scenario. As we drove across the state in the down pours, Wednesday, there were no leaks at all. Last Thursday night, we set the Airstream up, we are sitting inside and it starts to pour. I look up at the area identified above as having new repairs done last winter and the water starts running down (like a spigot) the inside wall and the upper wall to include the windows. We are out of the 115 degree heat indices, the temp is at 65 we are now wearing fleece and sweaters and we are NOT alarmed by this, at this point. Annoyed, but not alarmed.
We use lots of the beach towels that we no longer need, to keep the water from running into the seams of the side of the inside and down to the wood floor. After an hour of rain, heavy rain, the water stops coming in and the down pour continued all night long. So much rain we had a flash flood warnings throughout the next day.

My son, who is over at this College town going to school, says you know, it could be that the aluminum contracted in the cold after it had expanded in the hot temperatures. Or it could be visa versa base on all you smart folks out there. He had me stumped on this one, but a good solid answer to some degree.

Anyways, I'll throw it out there as there could be some discussion point already that addresses this, but if there isn't it would be interesting to see if this is myth or fact. "Myth busters" which he used to watch growing up.

So, within a four hour window, could the drastic temperature change 30-50 degrees "less" and altitude (4000 feet) "increase" actually do this to replaced aluminum panels based on how they were sealed?

I was very reluctant to do these repairs, as you normally don't want to mess with 40 year old stuff that works, but the sight of the dented panels needed to be fixed and the peeled Mylar had to go. We use this thing all the time now.

BTW, it rained most of the weekend and not a drip! Amazing. FYI, I do have a few tubes of Parabond, so i am prepared.

Look forward to the discussion.

Have a great summer of Airstreaming where ever you all are.


SL4BLLT

[overlander63]

A fast change in temp, plus the influx of cold rain, could have shrunk the panels. But everything should have shrunk along with them.
The new Olympic rivets have neoprene o-rings around them, so they don't need to be sealed before installing. Some of those o rings may not be doing their job. With as much rain as we got in the last week, just a couple of them could let a lot of water in.

[overlander64]

Greetings SL4BLLT!

I can't offer advice as to how much expansion may have taken place during your journey. My '64 Overlander has been towed all over the West, focusing on trips to the Rocky Mountains. We have experienced some similar temperature changes without inducing leaks . . . I don't know whether new work would be more likely to be impacted, but it may have been if one of the new rivets wasn't fully set and worked itself loose. Since water can travel several feet from where it finds its way into the interior of an Airstream, there are other potential places that may be more subject to water intrusion during a hard driven rain . . . . what I am thinking of would include roof mounted television antenna, front living room ceiling vent, refrigerator and or range vents . . . not every one of these would be possible as the floorplan of your coach will determine whether any of these three items might be a culprit.

Good luck with your investigation!

Kevin

P.S.: When camped in the Rocky Mountains, it is not unusual to awaken to the sounds made by the aluminum skin as it goes through its expansion/contraction cycle.

[Belegedhel]

Just for clarification, are you talking about panels that start out as a flat sheet, and then take on a curve once installed, or endcap panels that are formed?

The first question that comes to mind is "were your replacement panels made of the same alloy, and same thickness as the originals?" Assuming the panels are the same alloy and the same thickness, than I might suspect that the new panels are simply more "mobile" than the originals that have been glued/gooped/riveted into a unit for the last 40 years. That mobility may have opened up some seam or flexed the olypics enough to get a cumulative leak.

[SL4BLLT]

Thanks for the insight as well as other areas of interests to look at/for solutions. The panels are new from Airstream with the end caps being formed. The comment about water traveling far over a few feet allows me to look at other culprits that are on the roof.

The aluminum would be of a newer thickness compared to the 1972 Alcoa, so thickness could play a part as the new panels were installed under the older ones. I'll see if I can find out the width difference.

On the "o" ring on the rivets, possibly not seating that could be a good answer. We are working on two bigger rivets not seating the front awning bracket holder and have a temp hold until that repair can be made.


The stream of water was in an area that was noticable, but did eventually stop with the flow still being in the same location when it was noticed. We'll keep and eye on it and see if we can figure it out.

Knowing that they can adjust based the elements is nice to know. I'll check it out this weekend as we have more rain coming.

As mentioned earlier, the leak did stop which was a relief, we just want to ensure that when we let it sit this winter we have a grip on it.

I'll keep you posted and thanks for the input.

SL4BLLT

[Gene]

The newer panels are thinner I believe. You can use Acryl-r seam sealer to make sure the edges of the panels are sealed well, around the windows, and anywhere something is screwed onto the skin that was replaced.

The brackets holding the awning arms are leakers too and need to be very well sealed as on some trailers they have flat bottoms on a trailer surface that is not. Also check the courtesy (running) lights where they had to be replaced when the new skin was done.

Gene

[overlander63]

Originally Posted by CrawfordGene

The newer panels are thinner I believe.

The new panels are thicker, but are softer than the originals. I've sat through hail storms in Bertha next to a 20 year newer Airstream. The newer trailer had damage from the hail, our trailer did not.

[Gene]

Originally Posted by overlander63

The new panels are thicker, but are softer than the originals. I've sat through hail storms in Bertha next to a 20 year newer Airstream. The newer trailer had damage from the hail, our trailer did not.

Thanks for the correction.

Gene

[SL4BLLT]

Looking on the roof and the surrounding areas, everything looked pretty good. I'll give it one more look and see where the water would get to a point of getting on the upper side wall of the interior.

On the awning bracket, I'll make sure that that did not unseat due to travel and the wind from the road a 60 MPH for 375 miles. With the 21 foot awning rolled and tightened down it may not take much to move that much materiel when Murphy is traveling with you.

Thanks again,
SL4BLLT