What is the best way to bond steel to other metals, and steel to plastic?

OK, so basically, if i have an empty spray paint can, and i drill a hole towards the bottom, let all the paint and pressure out, then refill maybe a little more than half back up with homemade paint... what can i use to reseal the hole, so that when its sealed, i can repressurize the can (via butane or some other aerosol) without the seal breaking? I tried using some stuff called "faststeel", its a putty that hardens and is "steel reinforced" but even that could not withstand the pressure. i even put a metal patch over the hole, and stuck it with this putty, then puttied around the edges of the patch.. i the let it dry for an hour.. and THEN put gorilla glue over all the putty (after the putty had already hardened for an hour) i THEN wrapped it all in duct tape, but when i repressurized the can from the top valve, the paint still found a way to escape somehow, my guess is the pressure was too high and just tore through the putty seal.. so basically i am asking, what is the strongest epoxy or glue or whatever i can use tobond metal to metal (pretty sure spray cans are steel and other alloys)? i need it to be strong enough to withstand the HIGH pressure of a gas such as butane.. if not... what are some lower pressure gases i can use, in combination with less paint?.. thanks alot for any help, and if you have any ideas on the best way to seal this please help.. peace