Information on Hard Money Lenders

I am deciding to deal with a hard money lender for the first time. Usually, we put 20% down of the sales price and 20% down of the rehab cost and we have a bank that will finance the rest. However, we have multiple projects going now and will need to use someone else's money for our down payment. This is the scenario.... I need $24,000 and I was going to get that from a hard money lender at 6% interest and then take that to the bank and use it as my 20% down and have the bank finance the rest at around 4%. I have to pay the hard money lender 1.5% per month of that $24,000 until the 6 percent plus the money loan is met. Does that make sense to do or am I missing something? Thanks for anyone's feedback on this.