Well, I have tried using the flux-n-solder as a tinning butter. I applied the material with brass wool and brush like the video. I have then taken it outside to clean with baking soda to neutralize the acid. I washed the surface and then wiped the surface with clean thinner. When I applied the leadfree solder and pushed it down into the dents, it just slides off the metal surface. So I applied a little more and used a little less heat. Same results.