What on earth is this stuff?

[Ilikebeans]

Hey guys, we are stripping down the walls of our Ford e450 Econoline Shuttle Bus. It does not appear to have any metal on the walls or ceiling. Is that possible? What we do see looks like some sort of composite insulation? But it seems really strong. Should we keep it? remove it? will the bus collapse if we remove it/mess with it?

See photo for reference.

Thank you!

[Elliot Naess]

Looks to be what I might call a glass-fiber honeycomb sandwich.
Cheap, strong, stiff, and light-weight, with some insulating value as well.

I have a sample of a similar material here, except it came out of a military airplane. In other words, such "sandwich" and "honeycomb" construction is nothing to look down our noses at.

[Ilikebeans]

Thanks for the reply, do you think we should add additional insulation on the ceiling, or should the honeycomb composite suffice?

[Ilikebeans]

Originally Posted by Elliot Naess

Looks to be what I might call a glass-fiber honeycomb sandwich.
Cheap, strong, stiff, and light-weight, with some insulating value as well.

I have a sample of a similar material here, except it came out of a military airplane. In other words, such "sandwich" and "honeycomb" construction is nothing to look down our noses at.

Thanks for the reply, do you think we should add additional insulation on the ceiling, or should the honeycomb composite suffice?

[Rucker]

That is the structure of the bus. Two layers of fiberglass sandwiching the cardboard. Others have stripped the inner layer and reinforced the outer layer with lumber, enabling more insulation. I can't vouch for that approach.

I did not design our bus for subzero temps and left that structure intact in my bus, other than the few spots around windows that needed reinforcement due to water leakage. I'm using fiberglass and rigid foam on the outside walls behind the bed, counters, and other interior wall panels facing the outside wall.

I have a buddy heater, for cool temps, and will probably buy a diesel heater for the occasional cold night we might experience, hoping the power of the diesel heater will overcome any heat loss due to not insulating that wall structure.

I'll be using the bus in the summertime, so I don't know if just ventilating the interior space will be enough to overcome the heat of the sun. Toying with some ideas like removable insulation panels for the ceiling, but nothing firm decided yet.

[cadillackid]

that looks like a typical shuttle bus design.. I definitely wouldnt plan on any roof mounted accessories like roof racks, solar, etc..

[Ilikebeans]

Originally Posted by Rucker

That is the structure of the bus. Two layers of fiberglass sandwiching the cardboard. Others have stripped the inner layer and reinforced the outer layer with lumber, enabling more insulation. I can't vouch for that approach.

I did not design our bus for subzero temps and left that structure intact in my bus, other than the few spots around windows that needed reinforcement due to water leakage. I'm using fiberglass and rigid foam on the outside walls behind the bed, counters, and other interior wall panels facing the outside wall.

I have a buddy heater, for cool temps, and will probably buy a diesel heater for the occasional cold night we might experience, hoping the power of the diesel heater will overcome any heat loss due to not insulating that wall structure.

I'll be using the bus in the summertime, so I don't know if just ventilating the interior space will be enough to overcome the heat of the sun. Toying with some ideas like removable insulation panels for the ceiling, but nothing firm decided yet.

Do you think we should add extra insulation, or should the fiberglass sandwich be enough?

[Rucker]

The wall system has very little R value. It does heat up quickly with a buddy heater in the winter.

Hot in the summer. I used a portable swamp cooler with the windows open when I was working on it last summer.

For cutting down on drafts, I would look for opportunities to apply 1" rigid on the inside at window level or below wherever there is an opportunity. As mentioned I supplemented this with fiberglass batt to reduce the chances of humid inside air touching the outside walls where I can't see-again, behind counters, between the shower and the exterior wall etc.

For cooling, I'm putting in a couple of marine exhaust fans, and possibly a maxxair. I'm probably going to use a window a/c unit that I can pack away when not needed.

I'll also experiment this summer with, I don't know what to call them, maybe cushions? Sectional insulation panels that stick to the ceiling with neodymiums, again, just for the blazing sun days.

[jaxon cactus]

My daughter just bought a shuttle that has this same honeycomb. The problem is that she brought from someone who was also looking for the metal support pieces and he completely removed the inside wall on one side of the shuttle! Now there is only the thin outside wall of the shuttle and we are left with figuring out how to reinforce this wall. We will worry about instillation later, just trying to figure out how to build supports back in the wall.



I was thinking of using 1 inch rigid from the top to about7 inches below the windows and then brace the wall with 1 by 3's horizontally across the wall. My problem is that there really isn't any place to attach anything around the windows if I use the rigid foam. That is, if I want to put additional wall material inside against that wall for rigidity, like 1/4 plywood, there isn't anything to attach it to with this design. Still trying to figure out options.


There is only about 5 inches between each of the windows which doesn't leave me a lot of room to put some type of rib and rigid foam unless the foam is only used so the windows can be put back in.

[BeNimble]

Look at my nautibus thread, it shows how I removed all that and put in plywood with 2.25" of polyiso foam. As well as some 2x6 bulkheads. The right side honeycomb was toast, the left side wasn't great either, so I removed it all.

It had NO steel in it except what I call the 'kick bar' about a foot or so off the ground.
Honeycomb panels when in good condition is very strong.
The roof is also honeycomb and is very lightweight, so it doesn't need real strong walls frankly. But I note the A/C hanging in the back from the roof was pretty heavy. I removed it.

[jaxon cactus]

BeNimble, you stated in your Nautibus thread that you used rigid foam glued to plywood for your wall but it didn't look like you wanted to have windows. Here is a couple pics of my daughter's bus and she does want the windows. The thickness of the walls is 1 inch with the honeycomb and the inner fiberglass wall. I was thinking of using 1 inch rigid foam but not sure how to build a ribbing so that we can build on to the wall.

[BeNimble]

Yep I am not using the original windows, they are single pane and this is a 'tiny house' project for full-time living, not a camper.
I am not sure there is a problem with thicker walls with the windows. They have a retaining ring that holds the window in place, with some longer screws it should still work, or I sure hope so because my vintage motorhome repair I used 2x4, so the wall is 1.5 thick instead of the original .75 and plan to just put the original window in.

In any case, you can simply redo the original with foam instead of honeycomb, so gi;;u glue the foam to both sides and apply pressure and it should be strong.

I don't understand however, why you want to keep all the windows given where you are now (I can understand if they were all good and no reason to redo the wall).
A counter will be higher than the window bottom, I find that looks..well...ummm.