Attachment of underbelly to a new frame

[soldiermedic]

I have recently been pondering with my new frame how difficult it is going to be to attach a belly pan to it after the coach shell is dropped back onto the new floor. Someone told me that you need to have the belly skin on before the shell is attached to the floor. I am not sure if this is correct or not, but I wanted to ask the people that would know.

Has anyone done a shell off frame and floor resto that they had to put a new belly pan on? I will be doing it myself after it leaves the shop, so having it done there will not be possible.

Steve

[wahoonc]

Steve,
The factory puts the belly pans on first, then rolls the frame over for the shell. But I don't see why you can't do it afterwards. Just make sure you know where all your attachment points are I would suggest using a chalk line to make where you want to run your rivet lines.

Aaron

[uwe]

Originally Posted by soldiermedic

I have recently been pondering with my new frame how difficult it is going to be to attach a belly pan to it after the coach shell is dropped back onto the new floor. Someone told me that you need to have the belly skin on before the shell is attached to the floor. I am not sure if this is correct or not, but I wanted to ask the people that would know.

Has anyone done a shell off frame and floor resto that they had to put a new belly pan on? I will be doing it myself after it leaves the shop, so having it done there will not be possible.

Steve

Steve,

There were different methods of attaching the circumference of the belly skin over the years.
My 63 had it's belly skin wrapped into the floor channel. Without thinking much, I just copied the original design...didn't need to go through this agony, actually.
Your 68 has side skins that wrap under and become part of the belly pan.
Lynn's 55 FC's belly slides between the outer skin and the floor channel.
My 71 had belly pan pieces that went over teh outer skin, and were covered by a rub rail.
The only instance where the belly outer part needs to be done first is where it is wrapped. And even that can be altered.
As far as teh lower, flat pieces, those can usually be replaced individually, after the shell is installed.

[LI Pets]

I was thinking about the rivet thing.

I replaced a section behind the wheels to the bumper, I had trouble locating the old frame holes where the rivets were.

I used self tapping hex head screws, worked great real fast and you can take them out later easier than drilling rivets.

[soldiermedic]

When I get it back, it will be the shell on a new frame and floor with nothing below. I will have a resto shop that I am working with do the belly pan. I just want to ensure I dont medd up the monocoque design, and loose structural integrity. It is debatable if I want to use allclad for the belly since it will never be seen, but I think it isnt that much more expensive vs the new stuff that dents easier.

As long as the pan can be secured, and it is no concern to safety then I am happy.

Steve

[uwe]

Originally Posted by LI Pets

I was thinking about the rivet thing.

I replaced a section behind the wheels to the bumper, I had trouble locating the old frame holes where the rivets were.

I used self tapping hex head screws, worked great real fast and you can take them out later easier than drilling rivets.

Bob,
Do you remember the brand and size screw you used?
I have some of the kind with a tiny drill bit type top on the screw.
I tried this a few times when I built my 63, and found the little drill tops on the screws wearing out too fast, way before they made a hole in the frame material. They did work well when going into aluminum.

[boatdoc]

Originally Posted by soldiermedic

I have recently been pondering with my new frame how difficult it is going to be to attach a belly pan to it after the coach shell is dropped back onto the new floor. Someone told me that you need to have the belly skin on before the shell is attached to the floor. I am not sure if this is correct or not, but I wanted to ask the people that would know.

Has anyone done a shell off frame and floor resto that they had to put a new belly pan on? I will be doing it myself after it leaves the shop, so having it done there will not be possible.

Steve

Hi Steve; I have build a new SS frame, but before I have installed the shell, I have insulated it with Prodex on top of 1" urethane strips. This provided air barrier. Because I was not sure where exactly the appliances will end up, due to my changes in the interior, I could not install plumbing. This kept me from installing the belly pan. What I did was, I pre-fitted the new belly pan and installed it dry using #10-32 SS Truss head screws drilled and tapped into the frame. Now after I finish my plumbing I will prime and paint the belly skins and reinstall them when ready. To soften the contact area of screw heads to aluminum I will use #10 nylon washers. This method will help in the future should underbelly require inspection. Thanks "Boatdoc".

[cordesstudio]

Hi,

I'm new to the Airstream Forum as I have just begun to look for one. Been a dream for years. There is a 27' Overlander for sale (listed here) near me. I've contacted the seller and am waiting to hear. He mentions in his ad that the belly pan is mostly gone. Now, I'm ignorant. What is the belly pan? I assume form all I've read here that it's some kind of covering on the underside. Is it something one can purchase? Or does it have to be fabricated for an older model ('67)? Is it expensive? I'm in a small town with no RV etc. shop. Would a sheet metal person repair/replace it? Thanks much for any insight.

[wayne.yl]

Originally Posted by cordesstudio

Hi,

I'm new to the Airstream Forum as I have just begun to look for one. Been a dream for years. There is a 27' Overlander for sale (listed here) near me. I've contacted the seller and am waiting to hear. He mentions in his ad that the belly pan is mostly gone. Now, I'm ignorant. What is the belly pan? I assume form all I've read here that it's some kind of covering on the underside. Is it something one can purchase? Or does it have to be fabricated for an older model ('67)? Is it expensive? I'm in a small town with no RV etc. shop. Would a sheet metal person repair/replace it? Thanks much for any insight.

Cordesstudio,
I had the same dream for several years until I finally took the AS plunge.
You are smarter than I in that I did very little research before I bought. I also mistakenly took the seller at his word when he said everything was in "perfect" working order on the trailer, like the brakes! Oh was I mistaken. Anyway I say this because my advice for you is to go over any trailer you are thinking of buying with a fine tooth comb. If you don't know what to look for, ask here on the forum, there's plenty of experts to rely on. Regarding the belly pan.... If it is missing, that is probably because it either rotted off or was taken off for repairs. Either way, you now get to look at the lower frame close up. There are other vital components to inspect down there as well, like the amoount of rust and corrosion to the frame, the condition of the black water tank, fresh water tank, the axles and brakes. You can get aluminum to make another belly pan and if you are extremely fortunate, That is all you will have to do to the trailer. My guess is, its only the beginning.
good luck,

Wayne

[cordesstudio]

Hi Wayne,

I'm sure that's excellent advice. That's one reason I'm limitng my search to somewhat nearby so that I can look at it carefully. I have had a little experience in that I bought a small RV before I saw it. I did have an elderly uncle who was in the area look it over but he missed plenty, like the spongy floor, which ended up needing to be shored up, at sigificant expense! You all seem to be very experienced and I'm grateful that you're here.

So do you think it would be difficult and/or expensive to replace the belly pan? Is it just a straight sheet of metal (afixed as decribed in previous posts) or are there a lot of openings etc. for outlets etc. ? My RV doesn't have any kind of covering underneath. You can get under it and look directly at the gray and black water tanks and connections, shocks etc.TIA

[uwe]

Originally Posted by cordesstudio

Hi,

I'm new to the Airstream Forum as I have just begun to look for one. Been a dream for years. There is a 27' Overlander for sale (listed here) near me. I've contacted the seller and am waiting to hear. He mentions in his ad that the belly pan is mostly gone. Now, I'm ignorant. What is the belly pan? I assume form all I've read here that it's some kind of covering on the underside. Is it something one can purchase? Or does it have to be fabricated for an older model ('67)? Is it expensive? I'm in a small town with no RV etc. shop. Would a sheet metal person repair/replace it? Thanks much for any insight.

If only the flat pieces of the belly pan are missing, then that is not a catastrophe. However, there are 4 banana wraps ( the curved sections underneath each of the corners of the body). Those sections would be hard to find in good, original condition. Your trailers sides might wrap under to form the very outside wraps of the belly pan. Many 67's were built like that.
There are some openings in every belly pan, but nothing that a set of decent hand tools and average skill can't master. The metal for the belly pan is not a high grade aluminum, usually thinner than the skin, and of a lesser quality. For maing long cuts in aluminum sheeting, you might want to invest in some electric metal shears.
A forums search would reveal what others have used, but I bought my belly metal at Pilot Supplies, Avionics, and Homebuilt Aircraft Parts from Aircraft Spruce and Specialty Co.

[cordesstudio]

Thanks Uwe, Belly pan business much clearer now. Sounds doable.