I've got some rust forming on the bottom of my driver and passenger front doors, and on the seam of the cab meeting the floor, and the door sills, and around a loose drainage cap in the middle of the floor. It's a 2000, it's pretty much expected. I've replaced the rear half door for the passenger side and I have a replacement rear half door for the driver in the back of the truck now. Once I get that on there, I'll be ready for inspection.

I don't want to drive this truck through the winter without trying to do something about the rust. I know that I don't have the time or money to fix it right (sand everything down, POR-15 the entire cab inside and out, then bed liner over that anywhere that encounters wear).

Here is my current plan:

Get a handful of sandpaper, 80 grit, and give the rusty areas a quick knocking out to knock off any of the loose rust and to roughen up the paint where it remains. Then get some acetone and wipe down the area, then use a brush to cover the area up to the non-rusted sections with POR-15. Then, at least for the sides of the truck where it will be visible, to sand that down with 120 grit after a week or so and hit it with some rattle can gloss black.

Does anyone have any suggestions? Alternate plans?

I am a bit worried about the bottom of my front doors. They will pass as they are, but there is a patch welded in by someone prior to my ownership and the seam of that patch is rusted and flaking. I am worried if I sand it down too vigorously I might end up opening a hole in the bottom of the door. Perhaps I should just hit it nice and thick with POR-15 top and bottom and not worry about the sanding?

I will upload some pictures tomorrow when light returns.

 

The only way to stop rust is to sandblast it or cut it out. In other words, remove ALL of it COMPLETELY. Anything else will only last a year or two at most, if that.

 

I can be good with a year or two at this point. I know that more is required to stop it completely. The bottom of my front doors will need to be re-patched to be done right, the floor of my cab may need a patch as well, and re-welding at the seams. Lots of work I don't have time for.

I don't even intend to keep this truck long term. Just my stopgap till eventually I upgrade to an 01-02 Cummins 3500. It gets an average of 3k a year of use, very little, but it does serve as transportation in snowstorms and I might put a plow on it this year, just for my drive and maybe the neighbors, but nonetheless it would mean that it would be run in snow and thus salt.

On an unrelated note, while I mostly agree with you in principle regarding what is required to stop rust, I also agree with POR-15 and the proponents of it. Rust is a three part process, metal, water, and air. If you truly seal a piece of metal, it will not rust, even if rust has already started, it will not rust further because it has no moisture or oxygen. Unfortunately, the mud terrain tires on my truck essentially sandblast the underside of the sills, stripping the existing paint off and exposing the metal to oxygen and moisture. Similarly, to seal a piece of metal you need to prevent any contact with oxygen or moisture, meaning you need to get inside the doors as well as outside. My biggest reason to know that I will not prevent rust on this truck is to know that I cannot paint every part of the cab. Even if I strip the carpets and paint every inch of the floor I can see, there will still be a point where I stop, and it's there that the moisture and oxygen will enter.

*sigh* Fighting a losing battle.

 

Rust never sleeps.

 

Some pictures. I would appreciate opinions on whether certain items can be salvaged.

When looking at the rust a month or so ago I discovered that the plug in the center of this picture is loose. I can push on it and it pushes the carpet (rubber floor actually) up from inside.

My current plan for this is to wash with water, then wire brush, then sand the entire underside of the floor. Going to the beam to the right and right over the seam and up over the sill to the left, around the emergency brake cable, forward to the first seam and rearwards to the first seam or until I encounter solid paint across from the beam to the cab. To pull the carpet off the top and do the same, sanding and prepping at least 12in from the hole in all directions. Clean off the plug with a wire brush, then clean the whole area and the plug with acetone, followed by a brushed on coat of POR-15.

The condition of the sills:



I plan to treat them the same way, wire brush (of which I am terrified I am going to remove the entire seam and end up needing to weld in new metal), sand, acetone, POR-15. From front to back.

The underside of the driver side door:

The front doors have been patched previously on both sides with a ~2in wide piece of sheet metal.

On the driver side, this patch is rusting significantly. You can't quite tell, but the inside edge (top edge in the above picture) is separating and flaking away from the door. Any way anyone thinks this can be salvaged?

I also discovered this hole in the patch:


On the passenger side, the doors look quite good, the rear is new and the front patch is in good condition.


But beneath the body this piece, which looks just to be a folded piece of body sheet metal meant to come down and connect with the body mount, seems to be rusting out fairly badly:

Any thoughts on that? Will I eventually need to fabricate a new mount point to attach to the cab here?

Thank you for your time and effort in helping me out with this!