I'm building fuel tanks for my Wag 2+2. There aren't any drawings so I'm on my own. I built a wood mock-up that fits exactly how I want it when finished. I'll be welding the tank from 5052 .050 aluminum. I'm going to use a form block to shape the ends and baffles; basic rib construction. Problem is, how much undersized do I make the form block so it will produce the correct size tank? I know I need to subtract .100 for the thickness of the top and for the flange thickness I will be bending, how much more? Is the .100 enough or should I be closer to 3/16" all the way around?
Thanks,
Marty