Thomas Acoustical Ceiling Gauge!!!

[EastCoastCB]

I got a reply from Thomas in regard to what gauge their steel headliners are. They're 20ga.

Hi Mr. Brown,

Acoustical headlining is 20 Gauge.

We have a technical support line you may call at (855) 253-0419. We hope this information is helpful. Thank you.

Thomas Built Buses

Technical Support

 

[banman]

I got a reply from Thomas in regard to what gauge their steel headliners are. They're 20ga.

Good job going to the source!
Was the 20ga for a specific model or universally what Thomas uses in all their buses?

Does the same model bus use the same gauge non-perf steel if you don't order it with the "acoustical steel panel" ?

Yeah, I'm probing at the earlier discussions of "how strong is strong enough"
and will the sky fall in when you remove the inner ceiling panels...

 

[EastCoastCB]

Good job going to the source!
Was the 20ga for a specific model or universally what Thomas uses in all their buses?

Does the same model bus use the same gauge non-perf steel if you don't order it with the "acoustical steel panel" ?

Yeah, I'm probing at the earlier discussions of "how strong is strong enough"
and will the sky fall in when you remove the inner ceiling panels...

They're 20ga whether or not its perforated. Not any specific model, all their buses.

 

[DoxieLuvr2015]

Not the skin but the bones

I am not in any way an expert....buuuut how much strength is the interior sheet metal adding to the structure? Its the ribs and connections to the frame that are adding rigidity. Right?

Maybe I missed something from this thread LOL

 

[EastCoastCB]

I am not in any way an expert....buuuut how much strength is the interior sheet metal adding to the structure? Its the ribs and connections to the frame that are adding rigidity. Right?

Maybe I missed something from this thread LOL

Nah you didn't miss anything. Just putting the info out there to end the debate about what the ceilings are made of.

I don't know why some folks even pull the seats out they're so worried about structural integrity.
GOTTA break a few eggs to make an omelette.
Gotta remove a few panels to convert a steel can.

 

[o1marc]

I am not in any way an expert....buuuut how much strength is the interior sheet metal adding to the structure? Its the ribs and connections to the frame that are adding rigidity. Right?

Maybe I missed something from this thread LOL

Wrong. Anytime you cover the framework with sheet metal held with 1000 rivets, it adds structural integrity. It all works as a package. Whether we hurt it by removing it is not enough to be concerned.

 

[DoxieLuvr2015]

Very true

Nah you didn't miss anything. Just putting the info out there to end the debate about what the ceilings are made of.

I don't know why some folks even pull the seats out they're so worried about structural integrity.
GOTTA break a few eggs to make an omelette.
Gotta remove a few panels to convert a steel can.

Ja some folks go waaaaay over the worry factor here...however you do see that in a lot of specialty forums.

 

[banman]

They're 20ga whether or not its perforated. Not any specific model, all their buses.

Nah you didn't miss anything. Just putting the info out there to end the debate about what the ceilings are made of.

I don't know why some folks even pull the seats out they're so worried about structural integrity.
GOTTA break a few eggs to make an omelette.
Gotta remove a few panels to convert a steel can.

Exactly -- at least for Thomas bodies it confirms my suspicions (based on 30 years of being intimate with military helicopter/aircraft use and repair)
that while (of course) removing the inner steel ceiling panel will weaken the structure a bit -- it won't weaken it enough to change the buses meeting Federal Safety Requirements.

I've looked at a couple T-bone accident pix and that confirms my thoughts too that each seat is a mini roll cage adding waaay (math term!) more structure to the bus with how it's bolted to the chair-rail than the sheet metal on the ceiling ever could...

And for some actual math -- my seats weighed in at 1400 lbs. Figure nearly 750 pounds of that was the DOM tubing with gussets. That is some serious structure removal -- but like you said -- it must be done.

And even after the seat removal the sides are still stonger than most box trucks...

 

[Jolly Roger bus 223]

probably a little older technology but my 86 THOMAS IS 15 GUAGE ALL THE WAY AROUND.
i work with sheet metal and steel for a living and have a thickness guage to confirm.
not too step on toes but all of my panels for the roof and exterior are 15 guage.
but it is 1986 technology

 

[Marceps]

Information tidbits like this are part of the reason we could sure use a wiki.

 

[EastCoastCB]

probably a little older technology but my 86 THOMAS IS 15 GUAGE ALL THE WAY AROUND.
i work with sheet metal and steel for a living and have a thickness guage to confirm.
not too step on toes but all of my panels for the roof and exterior are 15 guage.
but it is 1986 technology

No toes to worry bout JR. IC is building theirs out of solid 16ga single sheets, at least on the sides.
But the 20ga they were using met the same federal standards.

 

[sepudo]

Wrong. Anytime you cover the framework with sheet metal held with 1000 rivets, it adds structural integrity. It all works as a package. Whether we hurt it by removing it is not enough to be concerned.

I totally agree with this. The sum of the parts is greater than the whole.

For that reason I wonder, what is the opinion of leaving my inner ceiling intact with the oem insulation and adding insulation and a new ceiling on top (or technically under since in inside the bus) versus removing hundreds of screws removing original fiberglass insulation, spray foaming the now bare ceiling and re-using the original steel inner ceiling and screws?
Something tells me that even the simple action of removing the hundreds of screws and really screwing them would affect the OEM rigidity which is important to me than maximum inner height.

 

[o1marc]

I totally agree with this. The sum of the parts is greater than the whole.

For that reason I wonder, what is the opinion of leaving my inner ceiling intact with the oem insulation and adding insulation and a new ceiling on top (or technically under since in inside the bus) versus removing hundreds of screws removing original fiberglass insulation, spray foaming the now bare ceiling and re-using the original steel inner ceiling and screws?
Something tells me that even the simple action of removing the hundreds of screws and really screwing them would affect the OEM rigidity which is important to me than maximum inner height.

School buses are overbuilt by 100%. The Bluebird Wanderlodge uses half the ribs of a bus intended for transporting children. Your worries are not valid. The Wanderlodge uses a cardboard wood type ceiling cover instead of metal. Most of us in a build don't replace the metal ceiling, but use something more aesthetically appealing.

 

[sepudo]

while I agree buses are overbuilt, my main concern is noise. as an example, I have a friend who works at a place that installs aftermarket speakers on cars. he says that often, simply removing panels and in installing them (correctly) makes them a little bit loose as compared to from the factory.

If at all possible I'd like to keep everything as is, remove the seats and lay down insulation on the floors, walls and ceiling and cover with panels. I figure unless I'm mistaken, the oem space that I don't touch would also act as an air gap/ thermal break, increasing the efficienty of my added insulation.

thoughts on that?

 

[EastCoastCB]

I 100% promise you that removing the steel interior panels will reduce the interior noise.

 

[sepudo]

How could removing a panel which acts as a noise barrier make my bus quieter? I'm sorry I don't see the logic, especially because the panels currently are not loose

 

[EastCoastCB]

How could removing a panel which acts as a noise barrier make my bus quieter? I'm sorry I don't see the logic, especially because the panels currently are not loose

A sheet of steel isn't any kind of sound barrier, even perforated.
They perforate them to reduce sound but having NO steel headliner is much quieter than having one.
The logic is- A can made of wood, cardboard, plastic, or similar is always going to be quieter than a steel can.
Remember the game when you were a kid where you made a "telephone" out of steel cans?

 

[o1marc]

Remember the game when you were a kid where you made a "telephone" out of steel cans?

Works exactly the same with paper cups. Bad correlation.

I see the open sections of ceiling with the ribs and partitions breaking up the sound better than it just bouncing off the flat metal surface.
The issues we are dealing with were not considered in the intended use of a bus. They were designed to be used for 1/2-1 hour trips, not life on the road

 

[sepudo]

Last scenario.
1) leave oem insulation and steel paneling AND add rigid foam insulation then some wood paneling

2) remove oem steel paneling and insulation, THEN add rigid foam insulation and wood paneling?

In that scenario I have to think option 1 would give me a better climate control due to the addition layer

 

[EastCoastCB]

Works exactly the same with paper cups. Bad correlation.

I see the open sections of ceiling with the ribs and partitions breaking up the sound better than it just bouncing off the flat metal surface.
The issues we are dealing with were not considered in the intended use of a bus. They were designed to be used for 1/2-1 hour trips, not life on the road

Exactly. NO headliner is still quieter than a steel one.

Maybe the cup was a bad example.

But its not hard to figure out why steel headliners are noisy. IF theres any benefit to it why don't some of you folks get steel headliners put into your daily drivers?