DIY rust removal on car door

I’ve got a 2015 Santa Fe. On the bottom of the rear passenger door some rust has appeared.

The ultimate question is what is the best way to remove the rust without going to a body shop?

Some context. Two years ago I attempted to fix this myself by sanding off the rust and repainting the area with a touch up paint kit that I purchased. The rust came back.

The rust is coming in at the bottom of the door, and there seems to be rust under where the rocker plate (I think that’s what it’s called) covers the door. So when I did my first attempt at DIY two years ago I was not able to reach all the rust. Pictures included. There is not a lot of rust but I don’t want to ignore this until it is a bigger problem.

My current thought is that the rocker plate needs to be removed so I can get access to everything and then make sure I sand off all the rust.

If I was to do the above, would that solve the problem?

Does anyone know how to remove/replace a rocker plate?

Is there a better DIY solution that I am not aware of?

Thanks I’m advance for any help/suggestions!

The part you call the rocker panel is actually the rear lower door trim molding.


It’s made of plastic and held on with screws and clips.

The hard part is removing it without breaking the clips.

Once removed, you first what to clean the area to be repaired with a solvent.

They make special product for this called Prep-Sol, but brake cleaner works too.

Once clean, sand the area til all the rust is removed, prime, and then apply a surfacer/sealer, then paint, and finish with a clear coat.

After the clear dries, you may have to follow up with a color sanding and then a buffing/polishing to blend in the repair.


You also may want to adjust the door gap. It looks small enough to be rubbing through the paint.

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Good ideas above. Also make sure the drain holes on the underside of the door are not clogged. Rain water gets into the door via the window seals, and it should just drain out the bottom of the door then to the outside over the sill, & not stagnate inside the door. Once you get the area rust-free, suggest to apply a thick coat of wax in the area, regularly. When I wax my cars twice a year, the final step, I apply a thick coat of wax on all accessible portions of the rocker panels. I don’t wipe it off when that area dries, just leave the wax on there. One vehicle is 50 years old, the other is 30. Neither has any rocker panel visible rust.


Do not apply wax to the repaired area for 90 days.

This allows full curing of the new coatings that were applied.


Thanks for the advice Tester. What you’re suggesting is what I was considering doing.

I’ve watched a video that explains that the moulding is held on by screws/clips and that you need to be careful when removing. But it didn’t go into how to remove the moulding.

Do you know of any resources that explain how do remove it? Articles, YouTube videos etc

From this video of the front lower door molding,

the only way I can see removing the rear is, remove the molding from around the wheel well, then open the rear door, and see if the molding slides of the clips pulling it towards the rear of the vehicle.

These are the tools used to remove vehicle moldings/trim pieces.


Thanks for the info.

I watched a few videos on removing door trim and it seems like you just slide/pull it off and if anything breaks you glue/soder it back in place.

Is this as simple as it seems?

Do you own a plastic welder?



I do not. But that’s only a few clicks away on Amazon.

If you go on a dealer site that has illustrations and parts list you should be able to determine the fasteners that are used. I’m just saying that it looks to me that the door is rubbing the paint off from the trim being too tight. Hopefully it’s not rust from the inside of the door. If it is just rubbing, a little clean up and treating and even just a touch up brush should take care of it if you can fix the tight trim somehow. Otherwise you’ll just end up touching it up every year.

No, it’s not.

I’ve found those plastic/nylon trim removal tools mentioned by @Tester above to be very helpful to reduce the chances of breaking the plastic clips. I don’t use that particular set, but same idea. I’ve tried both plastic and nylon versions, the nylon is a little better imo.

Repairing broken brittle old plastic pieces is not simple or easy.