Hi and welcome to BYC - thanks for joining us. I'd suggest posting on the predators and pest forum for the best advice although I seem to recall a live thread on the issue somewhere around.
Coons are one of the worst predators. They can dig, climb, jump down from trees, reach through openings and bite off whatever they snag. Plus they are persistent, extremely clever and have opposable thumbs. They can open almost everyone latch a human can, and I expect them to figure our combination locks soon.
The predator threads folks should be able to give the best tips on repelling them.