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Sneakinup · 04-17-2004, 02:18 PM

Has anyone every replaced the belly skin with something other than aluminum?

Would a product other than aluminum be in danger of tearing should some road debris hit it?

I've dropped most of mine, and it is a bear to work with and I have a lot of patching to do to get it back in place. I have been looking at exterior grade pvc panels (a.k.a. underdecking), and wondering why they wouldn't be a good substitute. Aside from the fasteners, there would be no problem of mixing metals and causing corrosion.

I know they are somewhat more flexible, so that would be addressed by attaching a steel angle between the current beams running the long ways of the trailer to allow attaching it in the center. Essentially, I would be installing 2 long lengths of this new material.

Just a thought. I will most likely just go and reinstall my aluminum, but was curious if anyone has tried anything else or if there were any other viable options.

Your thoughts and opinions are of course welcomed!

uwe · 04-17-2004, 02:46 PM

Sneakinup,
I have replaced large sections of my belly pan, using the old pieces for templates. I found it quite easy to work with, especially the new pieces.
I purchased a 4ft by 10ft section of aluminum locally, traced the old pieces with a felt marker, and went to cutting the new pieces with an air powered shear. Easy, and afterwards very very neat!
I imagine that pvc type material would be labor intensive to install, because of the extra braces needed. I am not aware that it has any kind of track record, and it would likely blow and flap when going down the road if not supported every 2 feet or so.
It is a bit of a hurdle to get going with the new aluminum, but quite rewarding once your underway and everything comes together as easily as it did for me.
I used the larger sized rivets, with larger heads for extra support. Now looking under the trailer is actually a good thing.

Sneakinup · 04-17-2004, 02:52 PM

Thanks! I've been thinking about new aluminum and having been in the aluminum business, know of a few good local distributors here in Tampa.

Did you do anything to prevent the corrosive reaction between your metal frame and the new aluminum skin? I am POR15'ng the entire underside of my trailer, but was wondering if some kind of barrier such as plastic film, or even a weatherstripping between the frame and belly skin would prevent the corrosion again. On the other hand, it lasted 32 years without too much damage.

I appreciate your input.

uwe · 04-17-2004, 03:16 PM

I did nothing to prevent corrosion, it was minimal when I removed the parts.
I guess California is relatively dry most of the time, which is why my frame was still sporting grey paint in most places, and corrosion was not an issue. ( At least not in the areas where i worked).
POR is a very durable product. It will produce a hard rubber like finish, preventing steel to aluminum contact everywhere but in the rivet holes.
Good Luck!

Ken J · 04-17-2004, 03:26 PM

Don't think I would ever do this, but I do know someone who replaced their belly with wood - worked well for them.

Ken

bredlo · 04-17-2004, 03:42 PM

Boy, I think giving up on the PVC idea so quickly is a mistake!

If you want to stick to aluminum, that's understandable, but given the benefits of plastic, and the availability of thicker PVC for better protection... this idea really makes me salavate. Imagine the underside of your Airstream feeling like it's built like a Hummer!

I've thought a bit about (and read a few threads that mention) using couregated plastics for sub-flooring (to avoid the degradation of wood over time) but never regarding the belly pan before.

Now, I'd be loathe to have a thick strip of white plastic showing around the entire base of the trailer, but there'd be huge advantages to using it in the non-visible areas parallel to the ground; meaning one would still have the aluminum belly pan visable around the edges but a plastic center area, which would still cover the majority of the underside. Think of it:

NO penetrating scratches, NO punctures, NO moisture corrosion, and perhaps better natural insulating qualities.

Here's the home run (keep in mind I haven't explored the insides of my trailer, so I don't really know what I'm talking about)

...by using thin metal rods (threaded at one end) that would extend from the frame down small through holes in the PVC, then sealing waterproof washers in place with vulkem, and finally using PVC nuts, you'd have an unbeatable way to access the bottom of the frame in 20 minutes without drilling the rivets out each time. Being able to access all your plumbing, the various LP lines down there, or replacing your soggy insulation every 5 or 10 years? How could you say no? Maybe more of your wiring and plumbing could migrate beneath the frame - freeing up space inside - because you'd be able to get to it whenever you need to.

Done rambling. Just trying to figure out another way to bring my 40 year-old trailer into the 21st century, and judging by how often I end up un-doing lots of work for forgetting a little detail, this would be heaven sent.

uwe · 04-17-2004, 03:56 PM

Brad,
Not a bad interpretation. BUT - i had a much easier time drilling out 50 rivets, than removing 5 rusted/corrodet sheet metal screws. ( vent hood outside cover)
Rivets are quick to remove, and quick to replace, with just a minimum of the right tools.
I don't want to discourage from trying alternate materials, but my situation has proven that the Aluminum SEEMS to be the better choice.
I did briefly consider using DZUS type fasteners under the plumbing to have quicker access in case of trouble, but the rivet gun won once again....

Sneakinup · 04-17-2004, 04:08 PM

Since my last post, I have been Googling all over the universe about pvc sheeting, and yes, it is durable and strong. Sometimes with properties even more desirable than aluminum. It even comes in large sheets in varying thicknesses, and I believe, it is lighter than the aluminum and very flexible.

I haven't come across any pricing yet, but I am certain it is fairly expensive. After I weigh out all the pro$ and con$, I will make a decision. It sure would be nice to have a non corrosive product in place. I found a site that even makes special rivets just for pvc and plastics.

Worst case scenario is that I reinstall my original belly skin, as it is easy to patch with some sheet aluminum I have laying around.

I have cleaned almost the entire underside of the trailer and POR15'd it. Amazing stuff, and it really goes a long way. I went off the deep end and bought a gallon. After weeks of using it, I have barely used an 1/8 of the can. I intend for this trailer to be handed down to my son. Hence, an Heirstream.

bredlo · 04-17-2004, 05:03 PM

Quote:

Originally Posted by Sneakinup

I intend for this trailer to be handed down to my son. Hence, an Heirstream.

Let us know what you find out about prices, Sneaky.

Uwe - good point about corroded screws, I s'pose rivets will always be very straightfoward, and since they're used everywhere else on the trailer, people doing major restorations probably become pretty good at dealin' with 'em.

I'm still really torn over the idea, but luckily won't have to make a decision until perhaps late this summer when tearing apart the GlobeTrotter. In the meantime, it's all just talk for me anyhow.

uwe · 04-17-2004, 05:44 PM

Brad,
Yeah, but it's good talk!

BobbyW · 04-17-2004, 08:13 PM

I am replacing my Belly Pan with Riv-Nuts attached to the frame. We had a Northern Tool store open up here and got them pretty cheap.

I will still have to use rivets around the perimeter, but that is aluminum to aluminum.

-Bobby

Ernie2007 · 04-20-2004, 05:13 PM

Have any of you considered stainless screws (no rust there)? Also if you're worried about the interaction of aluminum and steel use a vinyl or nylon strip between the two surfaces. Also you can weld on attaching posts and using nylon washers with a bushing attaced there will be no contact. Ernie

jjonesnc · 04-20-2004, 05:51 PM

Hello 1980 Ernie.
What make/model do you have? I ask becuse i have a 1980 Excella II and i seem to be the only one here with that Make/Model.
I was planning to do as you suggested and glue something to the frame between the bellyskin and frame. I did have corrosion between the 2 metals but it must be a slow process, wasnt too terribly bad EXCEPT where rust had collected on the skin and was wet under the bathroom. Big hole back there.
-Jason

Ken J · 04-21-2004, 07:08 AM

I have always used stainless steel screws to attach my belly pan - seems to work well

Ken

jaco · 04-21-2004, 10:08 AM

If I am correct most bellyskins are a continuous length fore to aft of trailer.?
Perhaps broken at some point with a seam, but I think most are one continuous sheet about 5 ft. wide X the length of trailer. I plan on exploring replacing mine with numerous sections with a batten strip between each. If the design of the frame cross struts (floor joists) will permit.
Are any of you using a similar method? The advantage I think will be the ease of reopening. Plus the easier task of rehanging.
Of course I have yet to open the belly and may find nothing under there to attach to.

I have accumulated a couple of rolls of what I guess is fiberglass reinforced something. It is the outside panel for cheap above ground round swimming pools. (Found both rolls on the curb where people had discarded). The stuff is very tough and durable about 1/16 thick and happens to be airstream blue.
Unfortunately both are just 48" wide. So if I used it I would have to do it in the sections.

I had not thought of installing the studs as was suggested above but plan to explore that further. Sounds like a great tip.

Ernie2007 · 04-22-2004, 12:32 PM

Quote:

Originally Posted by jjonesnc

Hello 1980 Ernie.
What make/model do you have? I ask becuse i have a 1980 Excella II and i seem to be the only one here with that Make/Model.
I was planning to do as you suggested and glue something to the frame between the bellyskin and frame. I did have corrosion between the 2 metals but it must be a slow process, wasnt too terribly bad EXCEPT where rust had collected on the skin and was wet under the bathroom. Big hole back there.
-Jason

Hi Jason,

I have a '86 34' LTD; the rust does not seem too bad but some of the screws holding the front pan have pulled through the pan. I will use a much larger washer when I re-attach it. By-the-by if some of you are getting rust due to water coming in from leaks in the walls you might wish to leave a small hole (glue a fine screen over it) in the center of the pan to drain out the water. rather than leave it.

silver suz · 04-23-2004, 08:25 AM

When people are talking about using rivets, are these the ones that have a rubber washer? (or something like rubber) and open up like a flower on the inside (for want of a better word) 4 loops that hold the rivet tight? Still have to clip the stem off and polish smooth.? Does anyone or everyone use these washers? silver suz

jjonesnc · 04-23-2004, 08:40 AM

Plastic washers are advisable on the belly pan because of the tendancy for the head of the rivet to pull thry the aluminum belly skin. Using the olympic rivets on the belly is not really nessecary because they will not be seen and will not have water sitting in the mandrel hole.
-Jason

amfab · 04-23-2004, 08:52 AM

UWE , or others, let me ask you about the pan removal and reinstallation process. I have a 67 Caravel and I was under the impression that the outer skin for the upper body comes down over the belly skin at the seem at the floor, with the belly skin wrapping under the channel that sits on the plywood floor. Is this the case, and if so how do you replace it without lifting the body? I must be missing something here, because everyone is saying that this isnt that hard
Thanks
-Andrew

Janets Husband · 04-23-2004, 08:56 AM

I have not responded to this thread earlier because I have been under the trailer reattaching the old belly pan. What a pain, I decided to use screws instead of pop rivets. My thought is if you ever need to get in there while out on the road, screws are easier than pop rivets to remove.
I found like many others the edge of the pan to be deteriorated, so I took galvanized flashing and reinforced the edge with that. Pop riveted it to the old aluminum pan, I hope that will last another 30 years. I do not think electrolysis will be a problem but who knows.
In looking at the pan whats strikes me, is they have spent a lot of time and trouble to seal these things but you still have big holes in the back at the waste dump and the dump hose/shore power box. I am going to try and at least seal these areas to varmints. I don't think you can seal it to dust and water.