Bellypan Replacement Project

[dbj216]

Well, I cleaned and sealed the exposed frame members, installed the foam board insulation, and riveted the new aluminum in place. Thanks for the advice from forum mambers. I've only done the rear, behind the tanks section, but I feel, with time and work, I can do the rest of the trailer. Here is a picture of the foam board, and a handy bellypan holder while I riveted it in place.

[Roadtoaster]

Nice work. I especially like the pan holder using the custom sized chunk of concrete!!!! That looks like some pretty hefty pan material.

[Chuck]

Cool! how did you secure the foam? (is that 5" of the rigid pink foam board stuff?)

when you do a new belly pan, do you use the old rivet holes, or just hold the alluminum in place, and drill all new ones?

[dbj216]

I used 2" foam board insulation. I cut it to fit in the frame cross member openings, which are about 57" wide and 24" long. I used a foam board construction adhesive and the caulk gun. The foam fit snugly in the openings. And I used two pieces for a total of 4". We're from Minnesota where it's always cold! The foam board did not absorb water after two days submurged in a pan of water. I think this is better than the wet fiberglass batting that was in there origionally.

The aluminum is .025 on 48" coil. I cut it to 60" long panels, and created a 60" wide by 7 foot long sheet with riveted seams every 48". I marked the center line of the sheet at 30". And I marked the center line of the frame. It is important it lines up on center before the riveting begins. Then I held it in place with the 2x4 holder and cement block risers. I drilled and riveted all afternoon! I did not attempt to use the origional holes.

I am trying to decide if I should drill some drain holes in the bellypan. The bumper wraps, sewer hose storage area and lid are not sealed, and allow rain water to run into the belly pan area. Why not let it drain out? The photos show the old bellypan corrosion, and the rear bumper area that is open to the elements.

The front of the trailer, ahead of the axles, is much longer at 24 feet. But I will use the same method. It will take me a good week of work to get it done. Maybe next year as we have traveling to do this summer.

David

[Chuck]

interesting. I'd be concerned that any water that does manage to get between the foam and the plywood would just sit there, and rot out the floor from underneath.

[SilverHoot]

Hmm, I am thinking the same as Chuck. I'm in the midst of this and will probably put spacers o a 1/2 to 3/4" and attach the foam. This will give some airspace for drying should it get damp.

[jaminalee]

I too am going to be replacing my belly pan and was reading about letting the water drip out. But am worried about spiders and insects getting up in there. So I was thinking maybe gluing a metal mesh on the inside on the aluminum sheet over the holes?

PS> What's the difference between belly pan and banana wrap?

[bwaysteve]

The banana wrap is the piece that wrap around the perimeter of the AS and is riveted into the lower side of the skin and the belly pan.

[fenderonly]

Newbie here from Georgia. Been reading this post on the belly replacement, a great help as I need to do the same!

Just got a 1987 Excella 1000, 32 feet a few weeks ago. Very nice, just a lot of TLC needed! Excellent original wood cabinetry, new hardwood floors, super nice original upholsetery and Airstream beds. Wood curtains still in front and dinette area.

So far:
All new clearance lights
New tires and shocks (American made Marathons!)
5 sets of mini blinds and replace screens on same windows.
Recertified and new heads on aluminum propane tanks
New regulator and hoses for the tanks
Rebuilt Moen kitchen faucet (cartridge, o-rings and aerator)
New gasket for hood fan vent (leaking water there)
new A/C filters
Lots of cleaning and polsihing!

Been on our first trip to Oklahoma and now back in Alabama a few days. Towing with a Hensely hitch and Dodge RAM.

Amazing, I am getting close to 15 MPG, 3-3.5 MPG better than my Fleetwood 24' that was 2000 lbs lighter.

More projects to do ASAP:

-Clean drapes and replace all the glides on the ones by the Dinette area
-replace belly pan behind and in front of holding tanks
-replace the Univolt with a more modern, regulated supply.

Great to be here and appreciate the Forum very much!!!

[Lothlorian]

DJ:

I like what you used to put the aluminum up with. The concrete block and wood. I have to change mine out because at the time I could not afford the aluminum. Now I am motivated to put a new one up.

Brian

[n8andm]

I have been looking for posters in the Minnesota region to know what they have been doing for our special climate conditions. I have to replace the belly pan on our Silver Streak. Where did you get your aluminum and how much was it?

[MyNancy1977]

What's the best tool to cut sheet metal...thus is what I have to deal with

[aquinob]

You want to try and drill out as many of the rivets as possible, then it should mainly fall down. If you can get the pan out intact, you may be able to reinstall it or use it as a pattern for a new piece. Just about any type of saber or jigsaw with a metal blade will cut through it. You could probably rip it out since it looks like its mostly gone with corrosion anyway.

[mover75]

Has anyone used or had the bottom side of the floor panels sprayed with closed cell foam insulation that is used in homes while having the belly pan removed? If so what type of results did you have? Thanks

[55AS]

Angle grinder or dremel tool with metal blade will cut the pan pretty easily. I cut mine out only between frame rails when installing tanks, leaving banana wraps in place.

[featherbedder]

If I replaced belly pan I would pull all of insulation under floor out as fiber glass soaks up water then where ever wet floor rots out also causing frame rust. Trailers that are not used in frigid weather does not need insulation, the only reason I see is sound deadener. Many other trailers do not use belly pans or put insulation where would get wet, weep holes in belly pan good idea, insulation bad.

[MyNancy1977]

Thanks so this is the whole belly pan right , it has patches as you can see.this was way south of texas san benito...sat for 9 years

[MyNancy1977]

Here's water tank...what do I do there , it don't work anyway

[aquinob]

Originally Posted by MyNancy1977

Here's water tank...what do I do there , it don't work anyway

The water tank is held up in place by a piece of 1" thick plywood that sits in rails. The downward face of the plywood is covered with a sheet of aluminum just like the bellypan. I dropped the tank and documented it some here:

My Airstream Adventure, Making a 1973 Overlander Our Own.: Dropped the FW tank and here:
My Airstream Adventure, Making a 1973 Overlander Our Own.: Tank is back in, new outrigger covers fabricated and weled. Wheels are finally all on.

[aquinob]

Originally Posted by mover75

Has anyone used or had the bottom side of the floor panels sprayed with closed cell foam insulation that is used in homes while having the belly pan removed? If so what type of results did you have? Thanks

It would probably work well for insulation but I wouldn't do it. One of the biggest issues with the original spun fiberglass insulation is that it tends to hold water up against the frame and promote rust over time. If you spray the whole bottom of the frame with this stuff, you will cover up some of the frame and thereby encapsulate it. If water can get in (and it will find a way) then you have set yourself up for trouble.

The best solution I have found is to use the solid foam boards cut to fit underneath between the frame members and held up with screws and fender washers. This should let the frame dry if any water can get up underneath since it can drip down and out. Remember, water that gets between the the interior and exterior skins wont be seen unless its a lot and you can notice staining on the plywood floor. It will eventually run down to the bottom as well and you don't want it to hang around any longer than necessary.

Here is a link to show how it came out on my rig: My Airstream Adventure, Making a 1973 Overlander Our Own.: Progress but at the cost of an eye injury