Understanding Private money loan with IRA

[Jessica Corona]

Hi there, 

I am looking at buying a Multi-Unit investment property. I would need to obtain a Private Loan that would be paid back in 1 year. I have someone with an IRA who is willing to loan me the money at 6% interest for 1 year with a balloon payment at the end.

It is my Retired  EX stepfather (never adopted). so there is no legal or blood relative connection. I am wondering if that counts a disqualified person?

He has quite a bit of money in his retirement accounts but is just worried about having to pay taxes or capital gains on anything if he were to loan me the money. 

I am looking for any advice on the subject. 

Thank you for your time,

Jessica Corona