Still learning

Learning lessons today. Spent some time on the practice project. All in all it turned out well. But not as good as it needs to be. I counter-sunk the number #30 holes in the aluminium angle. They were perfect if I used the 426AD4-4 rivets, but when I put the 0.040 dimpled skin over top the angle... Skin does not sit flush on the angle because the angle countersink was not deep enough. Makes perfect sense now that I think about it, but I realized it after I riveted. I also played with the air settings on the gun and found that lower settings work so much better that the higher settings I was using. I also discovered why the flush rivets do not sit quite so flush with the skin. My swivel flush set has a rubber ring around it which sits proud of the skin. Unless I press really hard with the gun, there is a possibility that the rivet is driven with its head slightly proud of the skin. I also noticed that I scratched the head of my flush set so now each flush rivet is being marred. After reading up on the forums, I see that you can polish the flush rivet set (one the rubber is removed). Did that and it turned out very nice!