It would help if we knew what the size tubes you need. There are
carving waxes that are hollow. Sheet wax can be formed around any
cylindrical object. The wax is cut into strips and formed around
the cylindrical object. The tubes can be wax welded on to the
surface of other wax. You can turn carving wax into any shape of
tube you need. (I have a paper on turning wax which i could send
you.) Lee Epperson