Help with patching a flat roof?

Hello experts I know absolutely nothing about roofs and am trying to patch my flat garage roof till. It has a small leak which is not much of a problem but some of the little granules are not on the roofing material anymore, so some of the black material under the granules is showing. The roof was put on 15 years ago and was hot mopped. I was told by a friend that I could paint it with Henry’s #587, #687 or use a product called Kool Seals which would seal everything up and I would be ok? I just want to get by till sometime next year and any advice would be greatly appreciated.

Don’t go with that Home Depot & Lowe’s Henry’s crap! Go with Karnak or Tremco. Get Karnak #19 roof cement & patch the leak areas, then coat the whole roof with Karnak fibrated alumacoat paint. It’ll buy you 2-5 years. I’m a 3rd generation roofer that has been using Karnak & Tremco products for over 30 years & swear by them! Good luck, let us know your out come.