Vehicle to Secure Private Money with friend?

[Account Closed]

How are you securing private money with friends, family or coworkers? In this case it is an old client of mine who has become a friend and has some money sitting around doing nothing. We have a solid trusting relationship and want to make it easy but still give him security. The capital will be used for rehab cost + landscaping on a 6U apartment that already has a primary loan. There is 125K of equity in the property and we discussed him lending up to 100K. I have heard to reach out to an attorney but we don't want to add the cost with the good relationship we have. Another friend gave me a very basic note that he used and had notarized when working with his father in law.

Any suggestions would be greatly appreciated. 

Andrew