There's a company who was looking for a super water barrier to prevent steel corrosion. There are a couple alternate uses that they've found for it.
http://www.neverwet.com/product-characteristics.php
Watch the video and be amazed. My jaw dropped. Hopefully the cost will be low when they release it for sale to the public. Not sure how long it lasts or what is used for cleanup for overspray, but I'm sure they mention it somewhere.
All I can say about this product is when it comes out, I will be coating everything in the garage that is steel with this!
Andy