paying off financing used for renovation prior to 1031

[David Quinn]

Hello, I have a duplex in Boston I've owned for around 17 years.  Currently in the middle of a large renovation with the goal of converting to two condos and selling individually.  I owe roughly 400K on the mortgage and should get somewhere around 900k - 1.1M for each unit.  Purchased for 560K originally; obviously quite a bit of depreciation.  Lets assume my basis is roughly 300k or so (before the renovation).  The renovation will run roughly 400-500K.  I'm using 2 HELOCs to fund the renovations.  One is connected to this property, the second to another property.  As I understand 1031 rules, I must purchase the new properties using all the proceeds of the sales of the condos (if I want to defer all taxes).  

My first question is - if I have to use all the proceeds toward the new properties, how do I pay off the HELOCs I'm using to fund the renovation?

Second, separate question - can I 1031 into a property I intend to flip?  Is there a minimum time I must own the new property before selling?

Thanks for any help!!  - Dave