Accessibility to dimple the doubler is difficult. I decided that I was going to use the rivet gun and a scrap chunk of steel to make the #6 screw dimples. I had ordered a chunk of steel from Metals Supermarket and will use that as a die holder/bucking bar. I had to clean up the steel and drill a hole to accept the female dimple die.
This setup is now used on the top side of the floor to allow use the male die in the rivet gun from below.
Once all of the #6 holes where dimpled. I then used the pop-rivet dimpler to finish all of the remaining 3/32" holes.
