Hi Graham, four things to watch out for with that set up, static and heat which has been mentioned also termites and if you get a flood its going to float off unless the termites have got to it then its going to sink, joking aside at least you are having ago at trying to get it setup and that’s what it is all about but I would do what stanwax (Rob) suggested and get something from maplins the boxes are cheap and durable, small and it will look the part when done, good luck with your project buddy.