The plumber messed up loads of things!
One of which is the bath. As it drains it leaks water from the join between the plastic fitting that is part of the bath (not the plumbing) and the fibreglass of the bath itself. Leaking is dependent on pressure (ie how full the bath is). So it is not massive or particularly floody, and it can be nearly stopped by pulling the plumbing fittings in one direction (suggesting how it occurred - the tight space probably means that the join has been under pressure for some time).
I want to smear some goo (under the bath) around the area and into the join, wait for it to dry, then have a fixed bath. Is this possible? If so what kind of goo would you recommend. I was going to use Evo-stick, smear it on and in, then waggle it around a bit to get it into the crack/split or whatever. But I am up for suggestions before I do!
Thanks for reading my problem, help gratefully appreciated. Wife impatient!
As rosebery has pointed out there should be a rubber sealing ring between the bottom bit of the waste and the bath.
Use silicone it will happily bond to both the bath and sealing ring and once set will ensure a waterproof seal.