Chocolate needs to be tempered to use it properly at as a coating.
http://bakingbites.com/2012/02/how-t...olate-at-home/
Here's a great article with info on fixing seized chocolate:
https://www.thespruce.com/how-to-fix...ocolate-521579
Alternately, you cold use candy melts, which don't taste like chocolate, but are super-easy to work with.