looking for Inner tube Lorry or tractor and material+ glue to mend pool cover

[spanish sheep]

Hi all

we are looking for an old inner tube from tractor or lorry doesn't have to hold air as we shall be cutting it up!!!

Also our pool cover has some small cracks in it does anyone know of material needed and glue to stick ( thinking we can patch it like a puncture???

any advice more than welcome thank you in advance