The only lock that Have found to be coon proof is a padlock, Locked that is it and even then they always seem to find away in.
These are in no way racoon prrof think of a racoon being asmart as a human child with the hands of one, when you go to buy locks to keep them out.
That's what I do you would be surprised at how many are out there that a racoon or a dog/cat can open.