Rivet Shaving Is Easy
There I was sweating the fact that the rivets on the rear baffle of my tank were sitting proud (by choice so that I didn't knife edge the skin when countersinking) and I was going to have to shave them. I purchased some disgustingly expensive stainless steel tape to try the "tape over the rivet and sand it down" method, and frankly I couldn't make it work. It took forever to grind through the stainless with the bristle discs I was using to start with, then there was the fact that you are trying to create a flush surface with a wheel rotating at 90 degrees to the surface. Not having a $400 30,000 rpm rivet shaver, I opted for the next best thing, my die grinder, countersink cage and Avery shaver bit. The first few rivets seemed to go ok, but the cage was getting warm because it was one of the cheap cages that has a bush instead of ball bearings, and thus couldn't handle the RPM without heating up. I had a bling bling heavy duty Zephyr one (although also a surplus steal) I purchased from Brown Tool for $14.50, but it would not fit my die grinder due to the shaft diameter, so I thought what the 'ell, I'll try it in my 1500rpm battery makita. I couldn't believe it. It worked a treat. The key was of course holding the foot firmly on the surface with your free hand, only using light downward pressure, then lifting off and clearing the chips every 10 seconds or so by hand, as the Avery bit doesn't seem to do a great job of self clearing. In all, I'd probably clear the chips about 3 times per rivet, but once I had the process down, I was averaging better than one rivet per minute, which was far faster than I could have dreamed of with the tape method.
So in a nutshell, if you've got a premium countersink cage and an Avery shaver bit, don't be frightened of having a crack at this. You can make the rivets perfectly flush with the surface. You can see in photo below a slight buffing of the skin surface on the right of the last rivet I have shaved, indicating shaving just past the perfect level, but only by a fraction of a thou. The one to the left is smack on perfect, and the one to the right is yet to be attempted. Just make sure when you start, you don't have one of those plastic boots on the rivet cage (they make it difficult getting good repeatability with the depth) and work down slowly to the desired height.
Just thought I should share this one. It feels good to have a win every now and again.
Tom.