He made our tank for the cat and works very well. Only OK for race boats though as no way these would get through CE marking etc. They also need to be a well vented compartment as they do leak some fumes.
So why do you want a bladder tank when we could do you a very nice light weight ally one that you then won't have to put in a box ? Fax over a drawing, (01202665572) or email me a sketch and I can give you a keen price.