attacking rust?
 

I have rust at the bottom of the passenger back door. I do not use that door a lot so I haven't noticed it. Looking for suggestions as how to fix this myself. I am aware the best way to do it is have it cut out and a replacement panel welded in but that would probably reach the value of what the truck is worth. Right in the middle I pushed in gently and my finger went straight through.

I was thinking of sanding it all down and seeing how bad the area is rusted strait through and either leaving the hole there repainted with a rust inhibitor or trying to bondo it pending on how big the hole is. Here are 2 pics of the damage:

if your truck is worth 30 bucks, then it wouldnt be worth doing
but i mean if you weld in a patch it shouldnt be much at all
if you have some metal, a sawzall, and a welder
then after cutting out the rust, and welding in the patch panel, just grind down the welds, maybe apply a little bondo to smooth it out, sand, and paint

I would have to have a donor car because of the area of the rust is cupped and curved for the door. I do not have access to a welder and would probably do a BAD job so I would have to get a body shop to get the part and weld it in, then paint and so on.

I know what you mean about just doing it right, I just didn't plan on spending that kind of money on something that doesn't affect safety or reliability.

I guess I will just see how bad it is when I sand it down and go from there.

Looks to me like its part of the outer rocker panel and not really the door. Rocker panels are cheap $40-50US.

You may try talking to a body shop about you getting the part and and doing some of the labor. Sometimes a local shop, not a franchise, will work with you.

Sunbelt rents little welders. Just depends on how much time and effort you want to put into it. Bondo does not really do a good permanent job on fixing large holes, IMO.

My first attempts at doing this occurred only 2 months ago. With a little, ok more than a "little", patience it's not too terribly hard.

For a quick, cheap fix
 

remove as much of the rusted metal around the hole as you can, give the area three coats of any good name brand rust reformer product allowing each coat to dry 24 hours, prime with Rustoleum rusty metal primer, and use 3M Auto Body Repair Tape to cover the hole. You can then prime and paint to match the bodywork or put a little Bondo over the tape if necessary to maintain the original contour and then prime and paint.

Be sure to get as much rust reformer and primer on the back side of the hole as you can to prevent the rust from spreading from behind.