Technical Rusty oil sump, should I worry?

[SB1500]

Wondering if the level of rust seen on the picture attached is anything to worry about. Rest of the underbody is clean for the most part and I know to expect some surface rust but I'm too much of an amateur to distinguish that from deadly hole prone rust!

Changed my oil last night, just at 99,822 miles and I plan on changing the filter and oil again at around 106,000 (6k miles in between changes). 1.2 Petrol Dynamic.

Attached a picture of my old oil filter which was a pain in the ass to get off btw!

 

[AB100]

Hmm. It took me 10 minutes to find mine, laid under the car. Ageing eyesight and the fact that I was looking for a red filter at the wrong side of the engine didn't help.To remove it I'd bought a rubber strap-wrench, with the thick rubber shockingly only just squeezing between the filter and the body. Any way, it came off fine once in place.As for the sump, perhaps some heat-proof paint would assure you.

 

[daveofkent]

Mine looked a bit like that and after covering it with vactan rust converter. It turned black and there's been no signs of it coming back yet after a year. I keep it handy now when I'm working on the car in hard to reach places so I can quickly give a coat to stuff that looks to be rusting. It's the consistency of water and goes a really long way.

 

[SB1500]

Mine looked a bit like that and after covering it with vactan rust converter. It turned black and there's been no signs of it coming back yet after a year. I keep it handy now when I'm working on the car in hard to reach places so I can quickly give a coat to stuff that looks to be rusting. It's the consistency of water and goes a really long way.

If I buy this, can I simply apply it to the rusted / starting to rust area and not worry about trapping the moisture and making the problem worse? I know there's some great products out there but if not applied by a professional that's the case and you never know until it's too late, you end up a few years later with it peeling, and a terribly weak / rusted surface below :-(

Googled it, looks like it delivers, but is the application complex?

 

[daveofkent]

If I buy this, can I simply apply it to the rusted / starting to rust area and not worry about trapping the moisture and making the problem worse? I know there's some great products out there but if not applied by a professional that's the case and you never know until it's too late, you end up a few years later with it peeling, and a terribly weak / rusted surface below :-(

Googled it, looks like it delivers, but is the application complex?

Hi there. Not at all complex! Normally just paint it on however it shouldn't be greasy so what I do normally is wipe a clean rag with some normal cheap window cleaner or something over it. It's really easy to use. . If you contaminate it you will ruin it so pour what you need in a small container. I use the plastic top of a mr sheen style aerosol. As I said before its really thin so it seaps right in. Leave it 30 mins and see the magic. Reaply if neccessary

You will not trap in moisture. The whole point of that product is it doesn't cover the rest it soaks in and converts it you can't really go too far wrong in my experience

 

[bluejohn125]

Hammerite Kurust or similar will do the same thing, give it a couple of coats and the metal will get a tough blueish finish that can just be left to protect itself. It would also take black hammerite on top as well even though they say put Hammerite straight on to rusty metal..

Any way I used those 2 products to salvage my very crusty sump on a 2001 Brava, after a good drill / grinder wire brushing. Previously I had assumed I would be changing it.

 

[earthman]

Mine looked a bit like that and after covering it with vactan rust converter. It turned black and there's been no signs of it coming back yet after a year. I keep it handy now when I'm working on the car in hard to reach places so I can quickly give a coat to stuff that looks to be rusting. It's the consistency of water and goes a really long way.

How's it looking now?

I've got some Vactan in the post, bought it for something else, the sump pan on my wife's Panda is looking rusty but I didn't think that you could use Vactan on parts that get hot??

 

[dac69er]

I would wire brush it, give it a quick clean with soap and water and rinse and dry as best you can. Then take it for a good drive to dry it right out and get it warm. Wipe over it with degreaser then paint with hammerite.
I did this with my cinq sump and it lasted 3 years without getting worse.

 

[earthman]

I would wire brush it, give it a quick clean with soap and water and rinse and dry as best you can. Then take it for a good drive to dry it right out and get it warm. Wipe over it with degreaser then paint with hammerite.
I did this with my cinq sump and it lasted 3 years without getting worse.

Personally I've not had much luck with doing that to rusty items, putting Hammerite or any other such paint on top of rust just covers it up basically.

I prefer the idea of killing/converting the rust first.

 

[dac69er]

If you seal in rust, no oxygen can get to it and the rust will stop.

I've used the likes of kurust before and not found it that amazing tbh.

When I did my sump I did it in the middle of winter and just gave it a quick wire brush a wipe and paint and it lasted brilliantly. You can put more effort in, but it depends how much effort it is worth.

 

[judderbar]

The manufacturers say Vactan should not be used on surfaces exposed to over 60C for long periods of time, but how often do we operate a car engine during this long period of time?

Incidently I once did the underside of a rusty car with blue household acrylic and it looked good for the few years I had it.

 

[DaveMcT]

The paint over rust products do work - but they always say to remove flaking rust. Something like the OP's sump will need to be wire brushed and ideally treated with a rust converter before painting.

The old Hammerite went brittle over time and chipped all too easily. A hot engine sump would make it even worse. The new formulations may be better but you could talk to Frosts (frost.co.uk). Here's their latest
https://www.frost.co.uk/eastwood-rust-encapsulator-platinum-us-pint-473ml.html

Alternatively, wait for it to leak and fit a new sump pan. Probably a lot nicer to do than wire brushing and painting overhead. Hey you could even brush on ordinary black polyurethane paint before fitting.

https://www.ebay.co.uk/itm/OIL-SUMP-PAN-FIAT-PANDA-PUNTO-GRANDE-EVO-SEICENTO-SIENA-STRADA-500-1-1-1-2-1-4/323411431598?hash=item4b4cd2d0ae:g:nhsAAOSwq9Zbf2EG:rk:1f:1&frcectupt=true

PS. There will be next to no oily drips, if the engine is left standing for 24 hours before taking the sump off. Drain the oil first of course.

 

[earthman]

If you seal in rust, no oxygen can get to it and the rust will stop.

Years ago I use to delivery stuff to a car body shop, they mainly dealt with classic cars, got talking to one of the guys working on an E type Jag, he said that once metal shows rust, it's almost impossible to get rid of it 100%, well apart from cutting out an whole area around it and welding a new steel panel in, he said that this particular Jag kept coming back every few years because the rust would start to 'bubble up' again underneath the sanded down/freshly primed and painted surface.

I don't think that it's just a case of cutting off the oxygen, if only it were that easy.

 

[dac69er]

Years ago I use to delivery stuff to a car body shop, they mainly dealt with classic cars, got talking to one of the guys working on an E type Jag, he said that once metal shows rust, it's almost impossible to get rid of it 100%, well apart from cutting out an whole area around it and welding a new steel panel in, he said that this particular Jag kept coming back every few years because the rust would start to 'bubble up' again underneath the sanded down/freshly primed and painted surface.

I don't think that it's just a case of cutting off the oxygen, if only it were that easy.

Rust is oxidation. Stop the oxygen, stop the rust.
That why metal dredged up from the sea is is such surprising condition. It isn't exposed to oxygen.

 

[earthman]

Rust is oxidation. Stop the oxygen, stop the rust.
That why metal dredged up from the sea is is such surprising condition. It isn't exposed to oxygen.

How do you explain the rust that forms underneath the paint then?

Some years ago many VW customers experienced this with their fairy new Golf's, the paint on the tailgate started to bubble up, it were in the middle of the panel, not close to where the wiper arm had been drilled for example.

 

[dac69er]

The rust doesn't always come from the outside that you see. You only need a pinhole for oxygen to get to the steel and continue the corrosion.

https://en.m.wikipedia.org/wiki/Rust

 

[DaveMcT]

The rust doesn't always come from the outside that you see. You only need a pinhole for oxygen to get to the steel and continue the corrosion.

https://en.m.wikipedia.org/wiki/Rust

That's always been my experience. I had some motorbike parts grit blasted and powder coated. The coaters heat soaked them to be sure all moisture was driven out, etc, etc. Two years later the same old areas of rust are coming back through.

For the sump you may as well get a new one. Add a coat of polyurethane black over the factory paint, but for what they cost it's not worth struggling to clean and repaint an old one.

 

[earthman]

https://chemistry.stackexchange.com...-does-it-matter-if-all-rust-is-removed-before

That site makes for some interesting reading, they say that it's critical to remove all the rust before painting.

"In the context of automobile repair work, assume a metal surface has rust over it. Does it matter if all of the rust is removed before the metal surface is painted? If it does matter, then why?

Yes, it does. Rust is weak, so any paint over it will hold weak. As long as the paint film over rusty part is broken, water and atmosphere contacts the metal and start to erode it, resulting in more paint film be destroyed. So it is critical to remove all rust from the surface being painted. Abrasive blasting, if you have the equipment, is probably the best way. While some paints may be applied over rust, it should be a very thin layer, and even then I would prefer traditional paint over cleaned surface anyway."

 

[Ralf S.]

The problem with painting over rust is that the paint surface will have "holes" in it, even if you can't see them with the naked eye. Some paint is also porous.

The more rust you can remove, but wire-brush or by abrasion, the better since it gives a smoother surface to the next treatment, whether that's a rust converter or paint.

If you have smoothed down and rust-converted anything, it's always worth painting it afterwards too, once the converter has dried, since it's an extra layer and will make the repair last longer.

Body filler (not on hot items though) will seal previously rusty metal, as long as there's no chance that moisture will get in from the other side (e.g. if a panel has been perforated) so if you just have a small rusted area in a panel it's better to give it a slight concave finish (i.e. hit it with a hammer.. ) so that you can use filler to level it back to the original height.


Ralf S.

 

[DaveMcT]

The anti rust coatings with any chance of working are really not low cost and might not solve the problem. A new sump is cheap so get a new one and a gasket and it's job done.

Ideally paint it first but that assumes the factory paint is well applied. Overkill would have it taken back to bare metal, properly primed and finished. That makes sense on a classic car with little or no spares availability but a bit pointless where spares prices are so good.