Using Equity Line of Credit for more REI?

[Marc Dufour]

Here is my situation:

I live in northern CA. I own 3 properties and live in 1 of them.

Property 1: value $1.1M, debt = $700K

Property 2: value $750K, debt = $400K

Property 3: value $500K, debt = $330K

I don't want to use the emergency cash on my savings, but I currently contemplate getting HELOC to invest in REI.

Assuming the HELOC are for 85% LTV, the line of credit would be close to $500K.

Is it recommended to use HELOC for REI? Can anyone share their experience?