Best way to access equity from a rental property?

I have been in the buy and hold strategy for many years and own 4 rental properties.  I own a condo out right and have enjoyed the passive rental income.  However, I would like to get more involved in buy, fix and flip.  I called my credit union to find creative ways to access the equity, however, most options led to personal loans (around 5%).  Most banks will not offer an equity line on a rental property.  I want to keep the property (not sell) and use the equity to start working for me.  I figured this is a great forum to find creative ways I can access that equity.  Thoughts? Ideas? 

Thank you BP world !