Moisture inside door; what to do?

[Oro_O]

I had to open up the driver's door on my new-to-us (relatively) 2003 civic - step-sons starter car. I have to re-pin the lock cylinder - the horrible lock quality Honda used back then caught up to it.

I didn't like all the moisture and debris inside the door well. Pic below. The vapor barrier is intact/ok. Granted this is the PNW, but...

I was thinking to clean it all out and dry it, then cover it with a coat of 3M spray undercoating. I've used that with great effect in the past on motorcyles, fenders, etc. is that a bad idea? I just don't think there's actually drainage anywhere I could block, is there? I can't find any. There was also moisture all throughout; the inner door brace, lock hardware, etc. were all damp or had a drop of water here and there.

The window gasket above is clean and conditioned with some Sil-Glyde in the fall, so it's as good as it's going to get.

Ideas? Is that a good idea or bad?

 

[OVERKILL]

There are typically drains in the bottom of the door, so I'd avoid doing anything that might block them/clog them. I'd also make sure they are clear. If you are going to spray with something anti-corrosion, a thin product that creeps like Krown or Rust Check is probably your best bet.

 

[maxdustington]

That's mold, clean your drains and make sure the vent on your door jamb is functional if it has one. Don't undercoat the inside of your door, just spray some "oil spraying oil" (lol) in there once the drains are clear like OVERKILL said.

 

[P10crew]

Most body shops around here use a product by 3m called cavity wax inside of body panels. No personal experience yet with the product but my body shop buddies claim that it's a hot item around body shops these days.

 

[PimTac]

Is that pine cone in the picture?

Was this car flooded?

 

[Mad_Hatter]

Originally Posted by P10crew
Most body shops around here use a product by 3m called cavity wax inside of body panels. No personal experience yet with the product but my body shop buddies claim that it's a hot item around body shops these days.

I don't think I wanna know what cavity wax is !...‚

 

[Nick1994]

Clean out the drains and hose out the door. Use some Mr. Clean or some other cleaner and a brush to clean it up. It'll drain once the holes are clear. Then dry it with an old towel. Check the other doors too.

 

[Oro_O]

Originally Posted by PimTac
Is that pine cone in the picture?

Was this car flooded?


No that weird blob is a weld - outer door panel to side reinforcement brace. I thought the same thing the first time I looked. Actually I thought it was something weirder...

Ok, I'll look for drains and clean it out, spray some Kroil or something in there. Thanks!


EDIT: So all three drains are wide open and decent sized; I guess that's just how much can sit in there without reaching one of the drains. I'm going to glue in some sound deadening material while I have it open, try to quiet this thing down. I got a bunch for my SUV so we'll use some here, too. The car's a little loud inside for my tastes... (though I really don't have to drive it, but hey, why not while you're there...).

 

[littleant]

Fluid film would work great. Comes in a spray can. Fluid film will creep into the seams. Been using it for years.

 

[Driz]

There's always moisture in there. Rain goes straight down the window andserps past the wiper seal. Moist air condenses yadda yadda... Just keep those drains open and flush once in a while. The place the rust inevitably hast to start is in the very bottom and inside that pinch weld where those flat tin panels are folded over each other. There's not much you can do about those except letting some oil seep down in there to keep out the water.
There's a few good ideas on YouTube of how to flood that pinch weld in the first couple of inches of the bottom of the door with either homebrew or commercial waxy anti-rust oil. Fill the bottom of that door with about 2 inches of oil mix and let it sit overnight and pull the drain plugs in the morning and save in the a into a couple of pans. You can use that for next year. The hard part if you want to call it that is getting it into the door which is actually pretty easyYou can take a tiny tube and slide it down the inside of the window and Make a funnel arrangement and fill it that way after plugging those drains with putty or take whatever. I find it easier to just plug them and drill a small hole in the back of the door panel ( back towards rear of car) that you can fit a Hose Into and tiny funnel then plug it after you're done however you like.
There's no better anti-rust oil that I know of them good old automatic transmission fluid. Trouble is keeping it in place. That's easy by just mixing it in a pan with some cheap petroleum jelly. You can toss dome canning paraffin wax in too for stickeyness. Just heat it, stir it up and pour it in warm. It's as close to free as it gets using dollar store PJ and saved ATF drainings. I've been doing this a while with my 20 YO. GMC. and the door bottoms remain rust free.
It's not a bad idea if you can spray some into the rocker boxes under your door . That's often easily accessed by simply pulling the plastic trim cover. Of course you need to spray it in there to hit the vertical surfaces . You can do that if you have a air compressor and some sort of refillable spray can. Just use a piece of copper or steel tubing And plug the end ( fold over)and drill some tiny holes down towards the end pointing in all directions. It all helps but make no mistake the rust monster wins in the end☹ï¸

 

[Oro_O]

Originally Posted by Driz
There's always moisture in there. Rain goes straight down the window andserps past the wiper seal. Moist air condenses yadda yadda... Just keep those drains open and flush once in a while. The place the rust inevitably hast to start is in the very bottom and inside that pinch weld where those flat tin panels are folded over each other. There's not much you can do about those except letting some oil seep down in there to keep out the water.


Yep, I get it now. I think I have a plan.

I checked the drains and they are quite big- i can push the tip of my pinky part way in. There's no way the would clog if I sprayed undercoating/etc. in there. What I will do is just wait until late spring/early summer when the weather is dry. I'll wash it really well, let it dry thoroughly, then put a rustproofing of some type in the bottom few inches, and do all doors.

We likely won't keep this car all that long, until he outgrows it and has experience under his belt. His younger sister is too much younger to keep it around for her. But when I go to sell it or hand it off I want it to be 100% as I would treat a long-term car.

 

[Toys4Life_C5]

Doors bottoms are a weak spot for most cars due to those leaky door glass seals. Sounds like you have a solid plan now!