How do you do BRRRR to get multiple properties in a few months?

[Alex Speiser]

I have a question. I'm biting at the bit to start using BRRRR. But here's my uncertainty:

When you get the first property, some of the resources I've explored talked about waiting about a year or so before refinancing. So, I wonder, does that only apply if you get a loan from an official institution like a bank, but not the case with a private lender?

ALSO, after getting the first property, having bought, rehabbed and are now renting, how do you get the next loan for the next property you need to buy and rehab (assuming that you're getting the second property just like a month after the first)? Do you have to find a new lender? 

What's the best strategy to do rapid fire like this so I'm not waiting months or a year or so before I do the next BRRRR property?

I'm ready to start doing this, but can't close this gap in my understanding.