using a 8 inch dredge sucking up large rocks Id go with 12 gauge for most of the body of this (to help keep the weight down) and a 10 gauge where the rocks actually hit the header to prevent it from getting bashed. BTW Id love to see this in action!! OR even better , Id love to run this if I could!
There are 3 grades of hardness-now maybe even more-but .125 1/2 hard was a good place to start. Hard cracks when bent, soft wears too fast but 1/2 hard just right. Don't remember that particular mil spec for composition anymore as haven't built a 8" in ages. You ever run a 8" gravel suckn' monster for any length of time-weeks/months on end?? Many secrets to body preservation as they'll work ya to death if not done right. Lotsa luck-JohnJohn
The ABS plastic probly is only .25 inchs thick BUT it is flexable to take the shock of getting hit multiple times by rocks! and it is molded , and that also helps strengthen it! Mikes idea of using UHMW is a good idea , even if you only use it on the "strikeing " area of that header!UHMW is 7 times more durable than steel and nothing sticks to it! GOOD suggestion Mike!