While going over my truck for future modifications, I found a hole in the bottom frame flange about an inch in diameter. I also found a small crack by the rear emergency cable support bracket also on the lower flange. I have been told that you shouldn't weld on the flanges of the channel. Is this true? I planned on putting a piece of angle over the area of the hole on the outside and running it up the side for a little extra support. For the crack I was just going grind and fill it. Before I make things worse, Could someone point me in the right direction of how I should repair these two issues.