I noticed around a month ago that the passenger side door of my 2014 Ford F-150 with a 3.7L V6, 169k miles and 6R80 transmission has a little bit of road rash and it's starting to rust. Luckily, I caught it very early. I sprayed the very bottom of the door with rust inhibitor and did a quick repainting of the parts that were rusty steel. The rust inhibitor I used converts rust and primes it in one shot. The upper part of the paint is still adhered to the metal, but it's bubbled up a bit. How should I go about permanently fixing this? I tried getting in touch with a guy who restores and paints cars for a living, and he hasn't responded.
I took a closer look at my passenger side door this morning and think I found the culprit. The drain hole was blocked by a fitting of some type. I'm assuming when Ford first manufactured my truck, one of the technicians who installed the passenger door didn't remove this fitting, and it's been in there ever since. The rust damage is pretty much in-line with the drain holes. Unfortunately, is indeed rusting from behind.
I looked at the drain hole on the driver's side door and the same fitting isn't there. It isn't rusting.
I guess now that the drain hole is clear, rust may slow down a little bit. As they say though, rust never sleeps.
@justin-shepherd Spray some Fluid Film or similar product inside the door to slow down the progress of rust from the inside.
I'll try that. The rust is basically right in the middle of the door, though.
I wonder if could jury rig one of those tiny tubes that come with WD-40 and concentrate it that way.
That's only the visible part. When you see rust bubbling up the paint like like that, it means it has rusted THROUGH from the other side. It is not "starting to rust" . It is rusted.
How should I go about permanently fixing this?
You don't. It won't stop. You will be fighting it from now on.
@imperator Thanks. I'll go underneath my truck tomorrow and look at it from underneath. It might be accessible from inside the truck. I think that lip on the inside doesn't fully cover that area.
you will still be protecting the metal from rust
as you can see, there's already paint on it. adding more paint to the outside won't help. You would have to somehow coat the inside of the body. Once the original factory dip passivation and zinc primer is gone , it's downhill from there. If it hasn't already started in other areas it will soon.
@imperator This is the bottom of the door, not a body panel though. I'll look at the inside of the door tomorrow. I think in that area, there's only 1 piece of sheet metal with a fold so it's not sharp.
@justin-shepherd the larger hole is supposed to be plugged. the smaller square one is where water should drain from. It sometimes gets clogged up though.
@imperator I took that plug out anyways. I'm thinking about putting fluid Film in there to help slow down future rust. How should I go about doing it, though? Just spray in that hole from the plug and be done with it?
@justin-shepherd Just spray it in to coat the inside bottom of the door, making sure not to interfere with any drain holes. I use a shop compressor and air gun for chassis spraying but an aerosol can should be good enough for spraying in the door. It will need to be resprayed periodically because eventually water getting into the door will wash it out.
@chucktobias The inside of the door is pretty sheltered vs the C-channel frame rails that were on my Ranger's rear frame. Even two years after I sprayed that FF in the C-channel, it was still sticking to it like it was when I first sprayed it, lol. Fluid Film is excellent stuff.
I took that plug out anyways. I'm thinking about putting fluid Film in there to help slow down future rust. How should I go about doing it, though? Just spray in that hole from the plug and be done with it?
keep in mind the big hole is exposed to the outside environment (it's outside the door gaskets). So if there's a lot of splashing, deep water, dust, debris etc then there's now a large hole it can enter. Maybe not the best for a farm/bush truck. On the other hand if it's just a pavement truck, it could help with airflow and evaporation.
I honestly don't know. I think preventing water from pooling in there will make the biggest difference. The spots where the rust has started are now kind of like sponges for holding moisture, so sealing them with a product might help a bit. If you can get the FF to creep all the way to the rust spots it's worth a shot. You might also check the condition of your window gaskets.
@imperator Would rust converter and then a coating of FF be a little better than just FF? I have Rust-O-Leum rust converter on hand, as well as FF. My only hestitation is I can't see the rust. I can use a straw nozzle to keep the converter inside the door. The stuff turns black when it contacts rust.
@imperator Would rust converter and then a coating of FF be a little better than just FF? I have Rust-O-Leum rust converter on hand, as well as FF. My only hestitation is I can't see the rust. I can use a straw nozzle to keep the converter inside the door. The stuff turns black when it contacts rust.
sure it'll help a little bit.
The only way to permanently get rid of rust is to cut it out and weld in good metal to replace it.
@chucktobias It's only surface rust, though. I guess I could sand off the rust to clean steel, prime and repaint it. I was just starting to get into bodywork and ended up having brain cancer 6 months later. I can't use my left arm anymore.
Yeah, if it's not to the point of perforation yet and not coming in from behind possibly sealing it with something like POR-15 then a topcoat of paint might work for a while.
@chucktobias I've never heard of POR-15, I'll do a little research about it. The driver's side door is still immaculate. I'm kinda skittish on doing this myself, just because I could possibly make it worse, lol. That's why I thought a friend I know would be more of an expert on it.
@chucktobias ya don't need to be an expert. Sand it to bare steel then shoot a rattle can primer, followed by the closest you can match the paint. Some automotive stores carry specific touch up paint, maybe you can get lucky and get the exact color.
Even if it is not a perfect job, you will still be protecting the metal from rust. Later you might be able to get it professionally serviced.
My "strategy" of sorts didn't quite work I don't think. I sprayed the heck out of the inside of the door today with Fluid Film, but I don't think I quite covered the rust from the inside. I used the hole from that oblong guard thing and tried spraying the stuff in there as best as I could without completely saturating the bottom of the door. The rust is too far inside the door to get a good angle on. I didn't wind up using that clear rust converter, either. Since I don't know the extent of the rust that's hidden in that passenger side door, I didn't want to risk causing more rust. I used that same rust converter on the outside of the bottom of the door and where there was rust underneath paint, it took the paint off and exposed a little bit of fresh steel when it cured into iron phosphate. I repainted the outside so it doesn't rust again-I can't do that from within the door.
I thought about getting one of those tiny cameras that mechanics use to evaluate the valves of engines and peering in there. I forget what those are called.
I got to thinking about something else, though. I wonder if I could place straight WD-40 in there and do it every month or so. Straight WD-40 is runny as heck, but at the same time, it will readily start coming out of the other drain hole if I put enough in. most of that rust is on the very bottom of the door, so gravity would be to my advantage. The original purpose of WD-40 was to keep Atlas Missiles from corroding. This would be basically the same thing.
What do you all think?
@justin-shepherd I think wd40 isn't very durable. You'd have to spray it every few months.
@justin-shepherd what about using these wands
That's a good idea, I didn't know they made those things.