Model Lungs

[Fat Amy]

I am trying to sort my model lungs in a bell jar out.
The original 'lungs' had popped and made a sticky gooey mess all over the inside of the bell jar and on the diaphragm.
I've managed to clean them all up and have replaced the lungs with bog standard party balloons, but can only get 1 of them to inflate!!
I have tried changing one then both of the balloons, made sure the pipes are not blocked but it makes no difference.

Any help would be really appreciated.
Thanks

 

[CraftyTech]

Is the diaphragm airtight?

 

[Fat Amy]

Is the diaphragm airtight?

yes

 

[Techno]

I am trying to sort my model lungs in a bell jar out.
The original 'lungs' had popped and made a sticky gooey mess all over the inside of the bell jar and on the diaphragm.
I've managed to clean them all up and have replaced the lungs with bog standard party balloons, but can only get 1 of them to inflate!!
I have tried changing one then both of the balloons, made sure the pipes are not blocked but it makes no difference.

Any help would be really appreciated.
Thanks

Try inflating the balloons before you attach them, this should sort it out

 

[Peter Sigsworth]

Try inflating the balloons before you attach them, this should sort it out

I agree with this - if one has a unstretched skin and the other an old stretched one then the stretched one will inflate and the other not. So blow them both up fully to stretch the rubber equally and let them down before you attach them to the tubes.

 

[Deleted member 32724]

I agree with this - if one has a unstretched skin and the other an olda stretched one then the strentched one will inflate and the other not. So blow them both up fully to stretch the rubber equally and let them down before you attach them to the tubes.

Yes, a good blow to stretch the skin tends to work.

 

[Fat Amy]

I'd already tried all of that, the only thing I can think it may be is the pipe, but its nothing obvious!

Thanks anyway

 

[Paul]

I'd already tried all of that, the only thing I can think it may be is the pipe, but its nothing obvious!

Thanks anyway

do they blow up if you puff them. if so it's probably the diaphragm, what do you use for that?

 

[Fat Amy]

The model works fine apart from only 1 inflating, its very odd!

 

[Jeff]

Yes, a good blow to stretch the skin tends to work.

Oooooh Matron!!!!!

 

[KayR]

Demonstration of the effects of COVID 19 perhaps?

 

[Paul]

The model works fine apart from only 1 inflating, its very odd!

are the balloons the same, maybe one has more resistance,

 

[Fat Amy]

are the balloons the same, maybe one has more resistance,

I've tried loads of balloons, I've told the teachers its an inclusive demo!

 

[Jeff]

Is there a blockage or restriction in the pipe?

 

[Fat Amy]

Is there a blockage or restriction in the pipe?

Nope, I've checked it all, its a mystery!

 

[Purple Cat]

Hairline cracks in the pipe / pinprick hole in the balloon?

 

[Fat Amy]

Hairline cracks in the pipe / pinprick hole in the balloon?

The balloon is fine, I've used so many, so it must be the pipe but I can't see anything.
I've given up now... it works enough to get the point across.
It's just that only 1 balloon fully inflates, the other inflates to the minimum point before it stretches.
The balloons have all been pre-blown!
I am officially stumped.

Thank you all for your suggestions

 

[karen b]

Is it always the same side that blows up properly?