Hey Daniel,
How does hard money loan exchange hands? - With a title company, an executed contract for the purchase and sale of real estate, and on the scheduled day of closing. That is simultaneously when everything is exchanged and managed by the title company.
they won't send a deed till 20 days after receiving full payment - If an individual is offering this to you, it is a red flag. You must go through a title company and have an executed contract.
how does the lender secure their loan - Almost all hard money lenders secure their loan with a 1st lien on the property.
If I need the cash 20 days b4 I get the deed? - If it takes 20 days to get the deed recorded with the county, that is a different thing. Title company should file with county within 3 days of the closing.
How do they know the value of the property to determine LTV let alone LTV after rehab? - Most lenders hire appraisal companies to have an appraiser give an accurate LTV and ARV based on construction plans and a walkthrough.
I called a company and they said I have to buy the property first and then refinance it with them. - Sounds like they don't do hard money then. Most hard money lenders are the opposite. They fund purchases, but not refinances. Mine does both.
If I have funds to buy the property why do I need a hard money loan? - Good question. Why do you? Are you looking for leverage to expand to more properties? Do you feel more comfortable in with seasoned professionals confirming what you are doing will end in profit to you? There are many reasons to use hard money, but if you don't have one, then you shouldn't use it. Using all cash is going to increase your overall profit, but at the cost of cash-on-cash return being much lower.