Wonder why it changed....

[Safari Tim]

I have watched the old VAC DVD of the Airstream program that showed the trailer assembly. It looks like from the 70's.

In that video they showed the flooring bolted to the frame with the bolts being bent to lock them in. Then the shell was lowered to the frame with floor attached and completed.

Fast forward to the year 2000 and I saw the show Genuine Article which showed the construction of an Airstream as well.

This showed the frame being built and insulation added but no floor. The floor was attached to the bottom of the shell somehow, then lowered on the frame.

Definiately two different techniques, so I wonder why it changed.

[fireflyinva]

I think it actually was from the 60s, since I understand that the older construction was abandoned in the early 70s. The consequense so many of us face with the older trailers is that if there is a leak and the flooring rots, the trailer detatches from the frame. With the modern construction, the flooring doesn't have that kind of structural value. My own take is that this probably is an improvement, but maybe there are benefits from the old construction that I'm not thinking of.

Mary

[wahoonc]

Originally Posted by fireflyinva

I think it actually was from the 60s, since I understand that the older construction was abandoned in the early 70s. The consequense so many of us face with the older trailers is that if there is a leak and the flooring rots, the trailer detatches from the frame. With the modern construction, the flooring doesn't have that kind of structural value. My own take is that this probably is an improvement, but maybe there are benefits from the old construction that I'm not thinking of.

Mary

I can buy that theory...but mine is a 1975 and the channel still sits on top of the floor, that is how I found out I had structural damage...the shell was wobbling on the chassis the floor had rotted out right where the main bolts go thru to the chassis at the A-frame....fixed now It would be interesting to see if we can pin down the exact date for some of these changes. Another one that comes to mind is the seperate banana wraps and whether they were installed over or under the sides...

Aaron

[Silvertwinkie]

At the factory about a month ago, the explained the process of construction. As they explained it, the "C" channel at the bottom of the shell holds the plywood to the shell. The shell, with the floor is then mated to the chassis. This was said to be a major time saver and I also think they said that since the shell supports a lot of the coach, adding the floor to the shell at the time of construction, prior to the union of the shell and the chassis, added even greater rigidity to the coach.

[74Argosy24MH]

It has to be a lot easier (faster) in an assembly operation to drop a flat floor on the frame than to try and align the flimsy shell over the floor channel.

John

[Silvertwinkie]

Originally Posted by 74Argosy24MH

It has to be a lot easier (faster) in an assembly operation to drop a flat floor on the frame than to try and align the flimsy shell over the floor channel.

John

My first thought was that it would take just as much time either way, but I could see how adding the floor at the time of shell build would add more rigidity to the shell which in turn does support the loads and stresses of the chassis from what I understand. The way it's built actually could save some time, how much I can't say, but when they are being built, clearly the plywood is treated just like any other shell part. They work from the ground up. My feeling is that as a customer, the floor added at the time of shell build is the real key because they literally lift these shells with two rolling cranes from the roof vent holes. The plywood clearly looked as if it helped keep the shell from flexing at all, which to me was of greater importance than the time Airstream said it saved....but on the tour, Don clearly said it saved them time.

[69 Silverback]

Just got the body of of the '63 . The banana wrap was between the body and the channel . In this case , it looks like the floor was put on the frame. Then the channel was attached to the floor , Followed by the wrap , which came up and over the side of the channel and was folded. Then the body with the ribs was installed. I found that the wrap was between the rib and channel and then riveted.

[Silvertwinkie]

Originally Posted by 69 Silverback

Just got the body of of the '63 . The banana wrap was between the body and the channel . In this case , it looks like the floor was put on the frame. Then the channel was attached to the floor , Followed by the wrap , which came up and over the side of the channel and was folded. Then the body with the ribs was installed. I found that the wrap was between the rib and channel and then riveted.

Sounds about right. All units considered vintage were built the old way. The new process has been in place for at least 3 years as far as I know...maybe even longer..how much longer I don't know....one new thing that they are doing on the outer edges of the plywood is that they are coating the edges with some sort of grey stuff (not sure what it is) to help seal out any moisture. I guess the edges were where most coaches have the floors soften up. I actually saw this new process and they actually cover from the outer edge of the plywood (before it's installed in the "C" channel) to about 4" - 5" inward. I think this process just started recently.

[uwe]

Another thought might be the availability of one-piece floors now, which might not have been possible in former days.
Looking at teh construction of my 1963, there's no way the shell can receive the floor and then be bolted to the frame. The wrap alone would prohibit this.
My (former) 1971, however, could have been built with the floor on the shell, the wrap would simply attach underneath the rub rail.
But the 71 had many floor seams, joining them for enough support to hang from the shell would be very time consuming.
I do understand that many newer trailers have one piece floors, which makes this assembly easily feasable.

[Inland RV Center, In]

Safari Tim.

The new method has increased production efficiency, and allows far greater accuracy in the shell to chassis placement.

Andy

[Jim & Susan]

Originally Posted by wahoonc

I can buy that theory...but mine is a 1975 and the channel still sits on top of the floor, that is how I found out I had structural damage...the shell was wobbling on the chassis the floor had rotted out right where the main bolts go thru to the chassis at the A-frame....fixed now It would be interesting to see if we can pin down the exact date for some of these changes. Another one that comes to mind is the seperate banana wraps and whether they were installed over or under the sides...

Aaron

Aaron, This is exactly the same problem with my ’73 Overlander. Rot in the same places. I’m replacing the whole floor in mine. I’ve now removed the entire floor and a good portion of the belly pan. The belly “wraps” overlay on the outside of the shell. The big problem, obviously, with this arrangement is that it allows water to leak into the belly pan. To make matters worse, the “beltline” trim that covers this seam appears to have never had any type of sealant placed over this area. End result, MASSIVE leaks into the belly pan. Once I got the floor up and before I removed the belly pan, I stood in the camper during rain. Rainwater runs (read that POURS) down the side of the shell and straight into the belly. This leads to bad rust problems. All of the outriggers forward of the wheels need work. Most aft of the wheels need some work. This also feeds the rot problem in the floor.

I’ve been searching for an answer to this problem. One simple approach is to Velkem the heck out of when it is put back together. A friend also suggested that I install a type of “Z” channel to divert the water (hummm…)

Anybody out there got any suggestions? I don’t want to have to rip all this stuff out in a few years and do all this over again. There is a pretty good discussion at the end of my main thread by several of the forum members. It can be found here:
http://www.airforums.com/forum...ad.php?t=15132

[Inland RV Center, In]

Jim & Susan

When you reassemble, apply Vulkem to the side sheet-underbelly wrap seam, underneath the rub rail.

That will take care of the water getting into the underbelly.

CAUTION: Do not seal the underbelly, as it "must" breathe.

Andy

[fireflyinva]

So, it seems that I was partially incorrect, the change is relatively recent. However, it does appears that the result is an improvement in the structural composition, even if Airstream's motivation may have been more production efficiency.

The shift in the 70s was to putting the bellypan on the outside. That appears to be a mixed bag--it created the opportunity for inward water leaks, but it also made bellypan removal easier and safer.

Mary

[Silvertwinkie]

Originally Posted by fireflyinva

So, it seems that I was partially incorrect, the change is relatively recent. However, it does appears that the result is an improvement in the structural composition, even if Airstream's motivation may have been more production efficiency.

The shift in the 70s was to putting the bellypan on the outside. That appears to be a mixed bag--it created the opportunity for inward water leaks, but it also made bellypan removal easier and safer.

Mary

Yup, Yup and I think Yup, but I'm not sure on that last Yup since I've never owned a vintage to look at the belly pan.

[wahoonc]

Originally Posted by Jim & Susan

Aaron, This is exactly the same problem with my ’73 Overlander. Rot in the same places. I’m replacing the whole floor in mine. I’ve now removed the entire floor and a good portion of the belly pan. The belly “wraps” overlay on the outside of the shell. The big problem, obviously, with this arrangement is that it allows water to leak into the belly pan. To make matters worse, the “beltline” trim that covers this seam appears to have never had any type of sealant placed over this area. End result, MASSIVE leaks into the belly pan. Once I got the floor up and before I removed the belly pan, I stood in the camper during rain. Rainwater runs (read that POURS) down the side of the shell and straight into the belly. This leads to bad rust problems. All of the outriggers forward of the wheels need work. Most aft of the wheels need some work. This also feeds the rot problem in the floor.

I’ve been searching for an answer to this problem. One simple approach is to Velkem the heck out of when it is put back together. A friend also suggested that I install a type of “Z” channel to divert the water (hummm…)

Anybody out there got any suggestions? I don’t want to have to rip all this stuff out in a few years and do all this over again. There is a pretty good discussion at the end of my main thread by several of the forum members. It can be found here:
http://www.airforums.com/forum...ad.php?t=15132

Jim,

I agree, what I am doing is putting bead of vulkem between the wrap and the body when I reinstall them, then after cleaning tubes and tubes of silver silicone off the beltline, I am reinstalling it with a light bed of vulkem at or just above the rivets. Then sealing the top of it with vulkem or Parbond...to be determined.

Aaron

[Inland RV Center, In]

Wahoonc.

Sealing the top of the rub rail with vulkem, will be difficult to do, and, have it look nice and neat.

If you used Parbond on the top of the rub rail, it will look great.

Andy

[wahoonc]

Originally Posted by Inland RV Center, In

Wahoonc.

Sealing the top of the rub rail with vulkem, will be difficult to do, and, have it look nice and neat.

If you used Parbond on the top of the rub rail, it will look great.

Andy

Andy,
I usually only use the Vulkem when there is a large gap. I also cheat and use the blue masking tape to keep from making an unholy mess . I prefer the Parbond for that application.

Aaron

[Inland RV Center, In]

wahoonc.

Any color masking tape works well for that purpose.

The trick is to let the vulkem set up for a couple of hours, or so, depending on temperature.

Andy