Thanks guys,
I looks as though there isn't an equivalent of Goop in the UK. Special thanks to Steven, who tells me that Home Depot do it. Next time I am in Boston (actually Cambridge), I shall do my usual visit to Home Depot and this time collect some Goop.
I was interested in the stuff as it has been recommended in past threads, for sealing leaky Cox reedies. Apparently it seals the leaks and doesn't attack the alloy like regular silicone. I am told that silicone glue is also good in this application, but I have not yet found it in the UK (just not looking in the right place!). I use a blue product called Hylomar for fixing pesky reedies, but I am always open to new ways of fixing the little critters!
Thanks again,
Andrew