How to Collateralize Investment Property?

I have 2 single family properties debt-free worth approximately $100k each that I would like to convert ​to a $100k line of credit to fund or supplement purchase and flip opportunities on an ongoing basis.

I cannot find a lender willing to do this. If you’ve done this before, your suggestions on strategy would be tremendously helpful. I’m open to private lenders, bank referrals or any advice you could give.

Thank you in advance. I really could use some assistance in this regard.

There are definitely commercial lenders who will do this, albeit at lower LTVs. You can expect to pay a higher interest rate, and probably a balloon or shorter amortization.