You should be fine if your only lifting 4-500 pounds, I would just be leery of lifting more than that until you get it all changed to 2". If you would like to redo the weld, you can get better penetration on the hardened steel by putting it in your oven at about 400F until it is hot all the way through, take it out and keep it hot while you make your welds, then bury it in the sand and let it slowly cool off.