[HoosierDaddy]

           
The washer cap rivets work best if you can access the back side. The tool I’m showing is needed . It attaches to a common (harbor freight) air hammer. You need someone on the back side with a heavy steel “buck” to go against the back of the rivet. The last pic is a shaveable blind rivet. They sell a tool to shave them. I just used side cutters and a small grinder followed by sandpaper. 
Byler Rivet has good information that you will find helpful.