Hey guys, i have a 2001 f250 with some rust on the bottom of my doors. What i did was pull off that black rubber strip and clean the rusted pinch weld real well then spray undercoating ( asphault kind) over the rust. I also had the small wand from a wd-40 can and put it on the undercoating can and sprayed it all upinto the drain holes so it would seep down and seal up the pinch weld so water wont get into it anymore. What has everyone else done to help stop the rust? Anyone see any downsides to what i did? Thanks

 

I would also spray some oil in the doors as well. I hope others chime in, my 04' is rotting right before my eyes.... I think there is a spray that stops rust..... or.....

 

There are various things that convert rust to something else, then you prime/paint over it.

Putting undercoating over rust and/or bare metal, no matter how well you cleaned it, is not going to last very long. If anything, if it was bare metal, you should prime it and paint it. With rust already there, it's best to use something that converts the rust to something else.

Undercoating is good for stuff that gets abraded - as in, blasted with sand/dirt/water. But overall, it doesn't do much good keeping the rust down, in my opinion.

 

Ive got a 2002 superduty doing the same thing. One of my doors is to far gone to fix. My doors are rusting from the inside out. Ive got an add in the wanted section on here, for a drivers side rear door (supercab). The bottom of that door is shot. I stripped all the rust off my savable doors with a stripping wheel on a drill. I got some rust neutralizer, and brushed some on the outside by the rubber strip. I removed all my bottom weather seals, and im going to do the same thing to all my doors. I even put a cup full down inside the door. I repainted the bottom and it seems to be holding up real well. The stuff that I used is called Rust Treatment by Permatex. That worked pretty good for me. The only thing I dont like about it, is you have to let it sit for 24hrs before you can paint over it.

 

i taped the doors off real nice por 15 primed them cause por 15 needs to stick to rust dide they mad a nice tape line por 15 the whole lower bottom looks nice and good stuff

 

I used to work for a guy that had old Fords (50's), whenever he changed his oil he would dump most of the old oil right into the doors until it ran out the drain holes. Made a mess, but his doors never rotted out. A slightly less drastic approach (some oil, but not 5 quarts) might be a good compromise between an oily mess and rotted doors?

 

Grease em up! Get some black grease from the parts store, pull the doorskins and grease her up like a really fat mother in law your trying to push out your front door! I know in canada it is popular to wipe grease all over the insides of bumpers and frames and other areas prone to rust you cant see. Many people used to do this in the backside of chrome bumpers in the 50/60/70's. Very effective, lasts a long time, and its cheap.

Heres a Q though, being as its a door, with drain holes, I wonder if it will leave greasy spots under the door drain holes? Maybe only a light layer would prevent this? I know the water should run off the grease and not mix, but I would hate to make a mess thats hard to clean up! Deffinatly would protect it though.

 

I love the grease idea, and even dumping oil in there, the only problem is i have chrome step bars which would become a mess; and i have a new driveway which i dont want to drip oil all over. Thats why i did the undercoating thing.

 

Sounds like a great idea to grease/oil the insides of the doors.

P.S. WD-40 and a scrub brush will remove grease and oil stains from concrete (been there done that)

 

On my 2000 Expedition I used Rust Bullet on the bottom of the doors, the first thing I did was to grind down the rusted area and cleaned it really well and applyed Rust Bullet. Than I used spray paint to cover the RB coating and thats all. It seems to work but I will find out durning the Chicago winters because they salt the roads way to much here.
~Gage~

 

Chicago puts down 2" of salt for every inch of snow it seems! Chicago has killed many a bronco for me. I finally stepped up t o the excursion cause I wanted something new and rust free. I hate rust like you cant imagine. I'm about to buy a new trailor hitch cause the one on my truck is getting rusty. Looks like the time I would spend cleaning it up wouldnt be worth just getting a new one for ~$300.

 

1 are you from Chicago? Ya I know sometimes on my street I can use a shovel on the salt they use way to much.
~Gage~

 

Yeah I live on the edge of the city near norridge, and work downtown. If you ever see an all black excursion with dark tinted front windows speeding down the left lane of the highway theres a good chance its me lol.

 

1 thats funny Im 5min from Norridge. Not to far from Wright College. I always loved the Excursion, wish Ford would bring them back.
~Gage~

 

Remove the undercoating that you put on there. Since you have rust there already, no matter how good you clean it, it will come back. You need to do maintenance on the doors now and the undercoating will prevent access to the metal and also hide any further rust.

Just keep spraying oil in the panels and keep them clean.