Sealing inner doors , what materials do I use ?

[RoadWarrior]

I just need some input on what materials to use to seal up these huge holes on my inner doors. I need something that is thin enough to bend and contour to the curves but yet thick enough so it will not flex .

I was thinking about using roof flashing, the stuff they sell at the home improvement stores that comes in a roll. Cutting it to fit then bending it to fit , then covering the back side in damplifier , using butyl rope around the edges , then use some self tapping screws to attach to the door . Then of course apply some damp to the outer part as well .

thanks

[OrionStang]

You can use cardboard sandwiched in deadener. Cheapest route.

Your idea should work, too.

ANd even if its not 100% solid, it still deadens and seals, and improves sound quality.