I figure OEM chat would be the best place to put this thread so here it is. I have real bad rust in the rear of my xj. Basically it is from the wheel wells to the hatch. The unibody rails are still good so here comes the questions. I think I will just go buy sheet metal, probably 16 ga since it will be easier to weld without blowing through since I just have a little fluxcore.
So can I just leave the gas tank in while I cut out the floor and weld? It looks like others have done it on here.
Also, I don't know if the method has a name but I saw that I just drill holes in the sheet metal then weld through those holes to the unibody? Is that the best way?

I would remove the gas tank and thoroughly cap off all fuel and vapor lines.

Cut out all the old rusty metal and weld you some 1/4" Diamondplate in there.

Since it's my dd do you think it could be done with the tank still in? And I'll look at diamond plate prices lol

The gas tank is incredibly easy to drop. If you leave it in there you should siphon and then purge the oxygen and fumes in the tank with argon or something that'll inhibit ignition. Siphoning can suck- you can remove your fuel pump relay and jump 12v to it with the fuel-rail-end of the fuel line in a bucket. It'll drain the tank in about 15 minutes but running your fuel pump dry can damage it, so only use it if you're starting with a tank that has quite a bit of gas in it.

Yep, fuel pumps are expensive and you'll have to pull the tank to replace it anyway.

Unless you have a floorboard hole right over the pump, in your case.

It would be best to cap the hoses and remove the tank, probably also do it in a very well ventilated area.

Could you do it with the tank? Sure, would you still have a Jeep after you do it, maybe not. Welding is something thats already risky enough, remove the extra dangers, If you dont want to remove the tank you can always just cut out the rust and pop rivet a sheet over the hole.

duct tape is also very good with stuff like this. I still have yet to fix the hole in my drivers side floorboard, I think im almost able to put a foot ball through it.

I might just move the tank. Or place some leather around it lol. But I just need to make sure I can do it quick if I do lower the tank since it's my dd

Hahaha jeez. I figured I'd just do it the right way

Well, if you decide to do it the lazy and wrong way, make sure your will is up to date. Pre-arranged burial and all that. I guess you could end up getting half-price on your cremation since you will have already taken care of the majority of it.

That way your survivors won't be put out too much.

Okay I'll drop the tank and do it right lol. Maybe I'll wait a little till I have a motorcycle to drive because every time I work on something it takes 3 times as long.