Hello Komatias

Thanks very much for that I didn't even thing of the drilling I just thought It may hold the bolts better. I does certainly sound like I will be best to drill and tap first then and then I think I will come up with a small slider door or something on the box section.

Do I have to use resin or can i just pour the sand in and then empty it in the future If needed ?

Back to the drawing board.

Thanks
Rob.