Beware ye plastic sill covers!

[Mozambique]

Okay, so this has been a 'to-do' think for a while on my 2010 V8, 212k km (owned since 2018). Took the plastic sill covers off today and quite a bit of rust. Looks a bit worse than it is i.e. no perforations thankfully. I will be spraying the whole of the underside with woolwax treatment shortly (had it done with Krown oil spray intermittently in the past), so it's kinda better late than never (Toronto, Canada, so road salt).

Pondering the sill rust. Think I will go with phosphoric acid rust killer and then apply woolwax on both sides (bit hard to get to the backside of the sill though). I was going to paint before applying woolwax but from experience with the gas tank shield, when the rust comes back it will bubble under the paint making the wax treatment pointless.

Was looking at Dinitrol RC900 rust killer, but it's expensive and hard to get, so probs just regular rust killer and then keep up with the woolwax treatments. Splurged on a compressor and spray gun, so more economical going forwards.

 

[scapistron]

Rust-Oleum 7769830

I go through a decent amount of this stuff every time I'm underneath. Wire brush what I can, hose it down with brake cleaner, hit it with the rusty metal primer. There might be better rust converter/neutralizer out there, but this one is low effort and quick. Other ones I've looked at require a topcoat after 24 hours, not very conducive to getting back on the road.

 

[Mozambique]

Thanks for the tip.
The old gas tank shield was heavily rusted. I wire brushed it, rust killer, primer, truck liner rubberized coating, Krown oil coating. I ended up with plate sized areas of paint lifting off when the rust returned. For that reason I am thinking any paint over rust is not always ideal. If I '****' the rust and then apply woolwax the wax layer will be in direct contact with the metal and will have a chance to work. The sill area is pretty protected, so woolwax should stay put. In other areas it may dissappear faster in which case rust primer may be better bet I would think

 

[BBLR3]

I guess its time to pull mine off (afraid to look!). I think if I was treating that area, I'd do POR-15. I've used it before with good results on various rusty metal surfaces.

 

[ugmw177]

not great but be glad you didn't have the side steps---they really cause the sills to rust out

 

[Jimmy Brooks]

how bad are rock sliders for this type of thing...

 

[scapistron]

I'm generally in favor of running boards and rock sliders with regards to rust. Pickups that have the worst rust tend to be without.

I used 2.5" stainless washers and plenty of blue loctite when I put my sliders on. I also drilled through the sill guards too so they're still there. I've also got rubber mud flaps to keep road spray off the body.

 

[richord]

I used POR 15 on my Canadian Jeep Wrangler which traversed much of northern Canada, the Yukon and Alaska. You brush off the rust with a wire brush, wipe it or blow it off with an air hose and apply 2 coats. I also used on my 1987 Defender and now applying it to my LR4.

It's expensive paint. I get the small cans because once you open it and replace the paint can cover it won't come off! It's like epoxy. Brushes on easy.

Don't get it on your skin. It doesn't wash off. Only way to remove it is with a scrubbing pad. Sounds painful but it's not. Don't let it drip on your garage floor or driveway, it will stay forever. If you get it on your clothes, it won't wash out.

It's PERMANENT! It resists rocks, road salt.

 

[ftillier]

I need to pull the rear bumper skin off and treat the tow hook area (and maybe more) as there is some rust forming there... I'm planning on using POR-15.

 

[Northern]

The rubberized "rocker guard" type coating is notorious here for making rust worse. Of you're absolutely dead set on using it, the metal needs to be pristine and primed/painted beforehand because the rocker guard does not keep air/moisture off the metal.

I'm all for fluidfilm/lanolin coatings overtop/inside of everything non-exhaust/brakes under the car.

If you use POR-15 keep in mind it does not hold up to UV exposure, and the surface needs to be very clean or it will peel.