Rust on rear passenger door corners

[kindofblue]

I just noticed the tiniest glint of rust on both the rear passenger doors, at the corner on the inside lip. It's on the same spot on both sides. I'm guessing I've just not been careful enough to wipe off this edge when getting the car washed. I can see how that space might accumulate some road salt.

A friend recommended drying it and dabbing a touch of Hammerite Blue Direct-to-Rust ( https://www.hammerite.co.uk/product/direct-to-rust-metal-paint-smooth-finish/ ). There's a hardware store with a $10 tin of this across the street. What would you guys do to slow this down in a low impact way?

[monkeydave]

that is horrible, are you sure it isnt covered under warranty which is 12 years for Structural corrosion but the surface corrosion is only for 3 years which yours wont be covered for

i have had some sucess with both types of Hammerite Kurust, either the green jelly that removes the rust before repainting or the milky one that turns it black before painting

it looks like it might be too far for that as there is a lot of bubbling under the paint that will need to be sanded off first

i would go to your dealer to see if it is covered under warranty before even touching it 

https://www.honda.co.uk/cars/owners/warranty.html

[Lord Voltermore]

I dont know this car in particular  but car doors often have small drain holes in the bottom  to allow water that enters via the window rubbers to drain  away.   These holes often get clogged with dirt etc  allowing 'water to gather where its shouldnt  oughter.'  Its a good idea to check the various drain holes in doors, boot hatch and under bonnet scuttle areas   are clear  from time to time even if there is no rust evident . Prevention is better than cure.  Even on the mk4  . (I've not yet had any rust problems  apart from a couple of false alarms that turned out to be brown spray grease used on hinges!  )

As well as painting the damage from the outside is a good  idea to treat it from the inside as well, if you can access it, perhaps by removing a door card.    You may also be able to prevent water gathering in that area  by using some automotive or plumbing sealant.

[pebbles]

What would you guys do to slow this down in a low impact way?

not good , if Honda don't want to know I would gently sand the loose rust off , treat with rust killer followed by some touch up.

Then , in  dry, warm , weather , get a can of rust inhibiting cavity wax like Supertrol and spray in the 3 drainage holes moving the straw around to get into the comers

[Glosrich]

Yes nasty. Just carefully rub it down treat with some kurust, allow to dry, then paint on zinc primer, then when dry touch up paint.

I've got some tiny bubbles from chips on the leading edge of the rear door, I think the front door sits too far in, so the edge gets chipped by road stones. Although I think mine has had the door painted at some stage, so maybe it's a bad repair.

It's a 2016 model, 47k miles.