hopefully sorted now thanks to gary BMX XXX
but thanks for the other ideas, some good ones in there
dordy that sounds like a great, practical approach but I'm better at riding bowls than carpentry (just to give you an idea of how bad I am with a hammer)
mr ace - already thought of paddling pool, but trying to avoid a 'you've been framed'-type disaster involving a big wobbly container of acid, can't be bothered to buy citric acid now I already have the oxalic, but sounds like a nice drink (is that how iron brew was invented?)
and finally, mr 1mancity2 - wheelie bins are for CATS
will let you all know how I get on!