The dimple die did a great job. The dimples opened up the bend of the flanges just a little bit, but I used a hand seamer to tweak the flange angle back to what it should be.

Here you can see that I ground down the corner of the die making it even more close quarters. It really worked well. I sure hope dimpling these baffles turns out OK.

I also dimpled the access hole flanges on all the bottom skins. You can see that I had to grind down the sides of my #8 dimple die so it would clear the nutplate dimples on either side. Yes that's right, I dimpled the skin for the nutplates. (so sue me ;-)

Actually that custom die worked great for dimpling the nutplates too. It was small enough to dimple the ears of the K1100 nutplates and since it makes tank die sized dimples, the nutplates nest very nicely over the skin dimples.

Here you can see my technique for installing the nutplates. Cleco on a nutplate, screw a screw into the nutplate (the screw has been cut down so it only screws one thread into the nutplate), install one rivet, remove cleco, install other rivet, remove screw, wham, bam, thank you, maam.