If you go to a real hardware store or a farm supply you can find very robust T posts. A raccoon can't get through my 2 x 4 livestock fencing and they have tried many times. They can certainly get their very effective hands through it to snag a bird, but they can't rip it or squeeze through it. I have the outside covered in hardware wire up about 4 feet to prevent the hands from grabbing a bird.
Walt
Walt