Purchase occupied duplex with hard money and immediately refi

[Adam Allard]

I have my eye on a great deal, but the seller isn't willing to wait for conventional lending. 

This duplex is currently being rented out, so I'd imagine that it would qualify for conventional lending in as-is condition. However, one of the units will be vacant soon and I'd plan on making upgrades at that time. So I'm wondering if it'd be possible to get a hard money loan to quickly purchase the property, and then immediately refinance out with a conventional loan. 

Anyone have experience with something similar? Would this seem like a good idea or bad idea?