Hi I am hoping you can help me. I have attached a picture of a football case. My 8 year old grandson made this for his Grampies who passed away and to whom he was very very close. He wants to put it on his Grampies gravesite. I need to glue the plastic cover to the base so it stays waterproof inside. Can you help me or give me some ideas on how I would go about doing this. I am not sure what kind of glue I can use that wouldglue the cover to the base but also not let any water in. Thank you so much for your help and I hope you can give me some ideas. My grandson will be heartbroken if he can’t put it at the gravesite. Debbie