If the property is cash flowing, why not pull a HELOC on the property to fund your next purchase rather than sell it?

Signature Credit Union allows HELOCs on rental properties. 

And if so, does anyone know a good lender that does HELOC on investment property?

I have a few questions regarding wanted to buy a full duplex or triplex.I would be using a HELOC on primary residence to get the 20% down payment + costs required to fix.1.

Do you guys think its a good idea to use Heloc as part of a down payment to buy a larger deal?

Next to 0 unless it is coming from a personal contact or a HELOC or something like that. 

Below are the details of each property, including purchase price, current estimate, and equity, along with their respective cash flows:Home 1 - Condo, (2 BR, 2 Bth)  Fayetteville,NC-  Purchase price $50,000 - Current Estimate $75,000, loan amount 0 = Equity $75,000Cash flow - Rent - $825, PM Fees $75, HOA Fee $100, HOA Assessment $163, Taxes $50, Ins $25, Loan Pmt $0 = Cash Flow $412Home 2 - Condo (3 Br, 2 Bth) Fayetteville,NC- Purchase price $89,000 - Current Estimate $155,000, loan amount 0 = Equity $155,000Cash flow - Rent - $1250, PM Fees $112.5, HOA Fee $231, Taxes $90, Ins $30, Loan Pmt $0 = Cash Flow $786Home 3 - SFH (3 br, 2 Bth) Little Rock, Ar - Purchase price $189,000 - Current Estimate $300,000, loan amount $85,000 = Equity $215,000Cash flow - Rent - $1500, PM Fees $150, Taxes $269, Ins $156, Loan Pmt $766 = Cash Flow $159Home 4 - SFH (3br, 2 Bth) Abilene,TX - Purchase price $225,000 - Current Estimate $315,000, loan amount $51,600 = Equity $265,000Cash flow - Rent - $1850, PM Fees $185, Taxes $583, Ins $145, Loan Pmt $1400 (0 Interest) = Cash Flow -$463Total Equity = $710,000Total Cash Flow = $894Sell, Sell with 1031 exchange, Cashout Refinance, HELOC'S...Too many options, i don't know what to do.  

But what if you purchase with alternate financing (sub to, assumable (look at VA but requires OO), owner financing, etc) and only did buy, rehab, rent, and repeat (one less R - more precisely not a refi but maybe use 2nd or heloc)?

HELOC How did you add value to the deal?

We have ~150k equity in our current home and are considering doing a HELOC to either purchase or put a down payment on an investment property.