2001 ext. cab. The bottom of the doors are rusting badly, especially the rear ones. Seems like maybe the drain holes are rusted shut. A few years back I sprayed them with undercoating to prevent this, but I made sure the drain holes weren't plugged. They are bad enough now that large pieces are flaking off. Do I have any options? I intend on Line-X'ing the whole exterior, so I could have the inner part of the doors done at the same time, but I would think it would still rust out from the inside.

 

yeah it reall sucks i have the same problem. last summer i wire wheeled them bottom of the 2 doors that were bad on my truck, then sprayed with rust converter then painted them with Rustoleum. it looks alot better now, but these dorrs rust from the inside out, water goes down there somehow.

 

It's really a bad design by Ford . Water actually splashes up there while driving , when the doors are closed . The water then gets under the door skin lip and just sits there . The lip will start separating badly from the rust behind it . This has nothing to do with the doors drain holes . To fix it , you can use an abrasive wheel to sand the crap out of the rust till it's all gone . Then use a good Automotive grade sealer/Primer , and then paint .

 

Yup, the lip on my rear doors especially is pushed out a solid 1/4" in places.

 

What do you guys think about using Naval Jelly or similar product to dissolve the rust before primer? I thought it turned it into carbon, but apparently not. Is primer alone enough to keep the rust down for a while, or should I apply something else? Will Naval Jelly do any harm to the painted surface?

 

my doors dont look too bad. i keep after them. i just try and keep them cleaned as much as possible. touch them up with automotive rustoleum every now and then with clear on top, then wax once in awhile, especially in the salt during winter. oh and i dont know if it helps but i shoot wd40 inside the drain holes to sit down in the inside of the seam

 

Great idea man!!! I knocked all the rust off of there that I could, and wire brushed. Followed with 2 coats of Permatex rust treatment, then 3 coats of Rustoleum. I plan to hit it with more Rustoleum today, then WD40 as you suggested. Thanks.

 

That is a good idea. I have to do mine up every year, but mines a 98 - I'm on my second set of rocker panels lol.

 

lol. you just cut it out and weld some new sheet metal in?

 

I have a question for you. In Kansas City, do they use salt on the roads during the winter months? If so after your repair is complete always clean your truck's parts that come in contact with any salt. Some parts of the country use chemical deicers for the road, this also shortens the life of a truck of car's body if not cleaned off. Just another point of view, not sure how cold it gets in your neck of the woods...

 

I have the same problem on my 97'. I took a wire wheel to them cleaned off all of the rust, hand sanded, cleaned used a rust eating primer/sealer, and then covered it with fiberglass bondo (yeah my doors were eated away that bad) used the primer sealer over the bondo and then painted. Worked pretty good, I still shoot WD40 down the holes every time I think of it. More time consumin than costly.

 

As far as trying to keep rust from forming or coming back you should use some type of amber rustproofing available at an auto body supply store. Don't use rubberized undercoat as it dries like paint then separates and gives moisture somewhere else to collect. and please don't spray wd-40 inside panels. if you ever need to get any paint work done wd-40 causes huge problems. it's silicone based and turns new paint to unrepairable fisheyes. tire shine does the same thing. if you're ride is going in for paint work don't armor all anything. or wd-40. or tire shine. we'd rather have it dirty. thanks!

 

Mine is doin the same thing. Could you clean it, paint it then run some type of silicone down the seams to seal it all up to prevent salt from getting back in there again?

 

I did, chopped up a Kenmore Dryer, - their excellent for Rocker Panels. - Drivers side was easy, - Passenger side was worse, the rust went up past the Rocker Panel body lines, so the replacement piece had to be contoured the same, -that was fun... The doors, -yep ,still keeping on them, -once a year.

I was able to get away with using aluminum rivets, the sell some that are easy to hide - Flush mount.

 

I really feel for you guys who live where rust is a problem ... my '67 Fairlane doesn't have a spot of rust on it (Arizona/California car, I haven't garaged it once in the 15 yrs. I've had it).