@Jesse Chambers IMO it's a great idea. A HELOC allowed me to scale up much more quickly and inexpensively than a refi on my properties. If I had done a refi instead of a HELOC on my 1st property I would have only been able to buy 2 properties last year instead of 5. I also would have been cash flowing LESS and paid thousands more in closing costs. Buy for cash, open a HELOC at 70-80% LTV, repeat as needed. It can also help you eliminate the need to keep going back for loans down the road, costing you several thousand dollars each. Currently I'm clearing my lines as fast as I can so I have available cash for the next great deal I see or a downturn.
BUT, be careful. Make sure you have cash reserves aside from the HELOC, buy smart, make sure your numbers fit your criteria for CASHFLOW, and make sure you clear your lines ASAP if you do the interest only option.
PenFed Credit Union has been awesome for me with their lines (no affiliation). Up to 80% NOO, minimal fees, desktop appraisals in some cases and quick to process the loans.
You should be very excited about your position and good luck!