HELOC to fund 100% fix and flip

[Zachary Engen]

Hello, 

 We own our house free and clear valued at about 580k. I'm considering using a heloc to fund a fix and flip. Plan to start small, buy a condo or townhouse wholesale that only needs cosmetic upgrades i.e paint, carpet etc. And pay off the heloc, Ideally in 90days or less. 

Heloc rates in my area are 8.5% whereas HML was quoted at 12% and 2 points.

once I finish the heloc can I pay off the principle only like I would with say an auto loan? 

Thanks for any info.