You also need a cutting wheel and some wire wheels for a electric drill too. I suggest you get all that at harbor freight too, and get the electric drill you pug in not a cordless one. Cordless sucks unless you can get some really expensive lithium one. I bought the red corded one at harbor freight for like $30 or something. And the cutting wheel you want is the 4 inch blue one. Dont get the cheap 3 inch red one. it doesnt cut worth beans. And get alot of 4 inch cutting disks too.
Also i suggest you get some rustolium rust reformer. Harbor freight sells it too, on my frame that was still in good shape but had alot of surface rust and some pitting i just banged it with a hammer to get all the chunky stuff off.. then used my wire wheel and went to town as best as i could. Then i sprayed 3-4 coats of rust reformer on it. Its been 7 months now and the rust hasnt come back.
Also for the 90A flux welder you should get yourself the auto dimming helm which is like $40 and keep it on 10-11 or so for the setting. You will also want a P100 Respirator which the pink duel cartriges which lowes or a welding shop sells. And get your self some wrap around goggles.. No glasses, actual goggles. And some hearing protection.
Trust me when welding it puts off alot of nasty fumes and dust.. Same when you wire wheel metal clean, specially rusted metal.. Without a respirator you are going to be tasting metal and rust in your mouth and have it stuck in your nose. Im sure you dont want to get cancer. And the goggles are for when you clean the metal so you dont get **** or little wire from the wire wheel stuck in your eyes.. And ear protection so you dont lose your hearing from cutting the metal and so forth.
Oh and you should get a different tip for your welder. The black tip that unscrews on the harbor frieght 90A welder is for a mig gas welder. Get a black tip for a flux core. It exposes the copper wire feed tip and gives you better welds for flux. You should also get yourself some .30 and .35 wire from lowes or a weld shop. Its better then the harbor freight stuff. And you want some .35 and .30 copper tips too
you can buy steel in sheets, like ply wood 4x8 4x10 etc. feet.......most places will even brake cut it a few times free. Lowes is not a great place for steel. Go to steel supply places.
The frame under that poor jeep will be worse, just not seen. Jeeps though it seems the Jks are rusting less? some are 10 years old now in the rust belt. Tjs and older seemed to have a special coating developed in w2 that would make it rust away after a few years, leave no trace. just a mark on the drive way....
Lowes was for fine for sheet metal for bodies and floors. They have 14-16-18 gague sheets that are pretty big and worked just for patchs like mine. But the thicker metal like 1/8th for frames and so forth was in little 4 inch by 3foot long sections which really sucked lol.
Also here our 98 ZJ 4.0 with extensive rust on the torque box and frame.. I fixed this with the harbor freight flux welder too.. This is where i had ti weld multiple 1.8th sheets together which sucked.. I didnt think to go to a steel supply place but then we pretty much have none, they are all out of business.
Anyway here is before and after. I know its alot of welds but doesnt matter, its fixed and its been holding fine for 4 months. And yes i left that bottom section open purposely there always was a drain there, but was too small and sand and dirt got stuck in the torque box and this is how it rusted from the start. And yes i know my welds are heavy handed.. If anyone doesnt like em they can suck my nuts, at least i fixed it myself and saved a ton of money
Now about that wrangler.. The only things i dont like that scares me is the rust thats inside the panel where the tail light is. That i dont know if you can fix tbh