Removing lower side panels (under the bolt tracks)?

[r0meboards]

Hey skoolie folks,

I'm seeing mixed things on whether or not folks remove the metal panel found underneath the "seat bolt tracks" (for reference I'm working on a Collins/Mid shorty). Are these structural? Mine still have the fiberglass insulation in them so I thought to replace them.

On his build series (which is using the same Collins bus body) you can see Navigation Nowhere grinding the panels off (see https://youtu.be/3f3DxlGItUo?t=536) but I haven't seen anyone else bothering to remove them. They're a much tougher metal than the panels between the windows and bolt tracks so I got some diamond tipped cut off wheels....

I'm also planning on keeping the bolt tracks in place since they are hardcore riveted to the frame. Any thoughts before I go too far? Thanks!

[o1marc]

Bottom 10" or so is the chair rail and is a structural member of the body, DO NOT REMOVE them. Normally we will push rigid insulation down into the cavity.

[musigenesis]

On a big "standard" school bus, the "chair rail" at the bottom is formed from a single piece of sheet steel that is bent into a horizontal flange at the top that the seats are bolted to, continues down to the floor then bends towards the outside, and then bends down to form an outside lip a few inches deep. This is screwed down into the floor and then the ribs of the bus are screwed into this rail - so this is not a part you'd want to remove, as your walls would no longer be connected to your floor (it's effectively impossible to remove anyway).

On a shorty like the one in the video, I think that track is a separate piece and you can cut it off without affecting the bus' structure. Just make sure it's not the one-piece part like I'm describing.

You might want to keep it, though. It could come in handy for attaching stuff in an extremely strong (and crash-resistant) way.

[r0meboards]

Originally Posted by musigenesis

On a big "standard" school bus, the "chair rail" at the bottom is formed from a single piece of sheet steel that is bent into a horizontal flange at the top that the seats are bolted to, continues down to the floor then bends towards the outside, and then bends down to form an outside lip a few inches deep. This is screwed down into the floor and then the ribs of the bus are screwed into this rail - so this is not a part you'd want to remove, as your walls would no longer be connected to your floor (it's effectively impossible to remove anyway).

On a shorty like the one in the video, I think that track is a separate piece and you can cut it off without affecting the bus' structure. Just make sure it's not the one-piece part like I'm describing.

You might want to keep it, though. It could come in handy for attaching stuff in an extremely strong (and crash-resistant) way.

Thanks for this! Here's an attached photo for closer reference – you can see I started to get it out and then thought the better of it. The change in color towards the bottom comes from a "L" shaped metal panel that was keeping the flooring on.

[musigenesis]

Originally Posted by r0meboards

Thanks for this! Here's an attached photo for closer reference – you can see I started to get it out and then thought the better of it. The change in color towards the bottom comes from a "L" shaped metal panel that was keeping the flooring on.

Hmm, on my school bus (a "regular" one) I might consider cutting off just the flange at the top, but I don't think I would want to cut it that close to the floor (some people here have done so, at least in a couple of gaps so they could move their door).

I've cut my own bus open so I understand how it's structured pretty well. With shorties like yours, I don't really understand how they're built (although I imagine it's similar) so I don't know if this is a good idea not. Seems like a lot of work, though, that you could avoid by just building your interior wall over it, even if it has to stick out a little bit.

[Meathead]

Do not remove. The consensus around here is that it is structural.

After picking most of the insulation out of there from the top, I melted the rest with a torch.

I was kinda surprised that the foam sprayed in there cured nicely. I know this bcuz I have cut holes thru it for my fresh water inlet and fridge vent.

Peace

[r0meboards]

Thanks all! Update - I messaged Navigation Nowhere to ask about why he was cutting it out in his video. He said he cut off some of the sheet metal in order to expose it for sprayfoaming. The chair rail stays there except for a big chunk that’s cut out. If the attachments to the floor / bolt track are still in place, would this preserve the structural integrity while still allowing me to remove the awful fiberglass that’s in there? See attached photo...

[JackE]

Originally Posted by r0meboards

Thanks all! Update - I messaged Navigation Nowhere to ask about why he was cutting it out in his video. He said he cut off some of the sheet metal in order to expose it for sprayfoaming. The chair rail stays there except for a big chunk that’s cut out. If the attachments to the floor / bolt track are still in place, would this preserve the structural integrity while still allowing me to remove the awful fiberglass that’s in there? See attached photo...

Most of the original insulation can just be pulled right out the top by the chair rail. What doesn't come out easily, make a hook out of a piece of rebar to reach in and pull it out. What I have pulled out so far has come out in full pieces and fairly easily. I haven't even had to use the hook yet.