How to deal with this undercarriage rust (pics inside)

businessdit

Hi all,

I have a 2015 car with considerable undercarriage rust.
Looks like only surface rust, but I want to treat this now.
Was a north UK import... so pretty bad for the age i think.

Can anyone advise what i should do about this DIY?

If I remove as much as I can with wire brush and then spray a few coats with Schultz paint would that work? Any other products you would recommend?

If I can't remove all the rust does that mean that i haven't really tackled the problem. How much of the rust do i have to remove?

Don't want to cover it aesthetically and then still have the problem underneath with it rotting away.

Also do I need a primer before the Schultz is applied?
Any advice appreciated. Want a long term solution and reduce any damage done.

See pictures below:
https://ibb.co/DC5dcvb
https://ibb.co/xJFq9QW
https://ibb.co/QDfwGzt
https://ibb.co/nsMQ2xz

THANKS!

Toyotafanboi

I dont think you'd ever clean that up properly to the point of where you wont see it coming back through.

I'd probably try to do a good job on the bits on the bodywork as that will be a problem in the future and let the running gear components go, they're too far gone to turn around IMO.

What is it? Something commercial anyway with the leaf springs.

mickuhaha

If DIY, Try and remove as much rust as possible, get a few attachments for the end of a drill and get as clean as you can, then use something like Permatex 81849-12PK Rust Treatment. Then paint it with a primer then finally a top coat. If you miss any rust it will just kill From behind the paint. Don't paint the exhaust or you will smell it for awhile.

KB22

businessdit wrote: »

Hi all,

I have a 2015 car with considerable undercarriage rust.
Looks like only surface rust, but I want to treat this now.
Was a north UK import... so pretty bad for the age i think.

Can anyone advise what i should do about this DIY?

If I remove as much as I can with wire brush and then spray a few coats with Schultz paint would that work? Any other products you would recommend?

If I can't remove all the rust does that mean that i haven't really tackled the problem. How much of the rust do i have to remove?

Don't want to cover it aesthetically and then still have the problem underneath with it rotting away.

Also do I need a primer before the Schultz is applied?
Any advice appreciated. Want a long term solution and reduce any damage done.

See pictures below:
https://ibb.co/DC5dcvb
https://ibb.co/xJFq9QW
https://ibb.co/QDfwGzt
https://ibb.co/nsMQ2xz

THANKS!

I have used this product on my classic.You don't need to paint after using,it leaves a visible film after proper application. As long as you remove loose rust, VACTAN will form a coating it can be left like that or painted over. Good luck,keep us informed!

my3cents

Another one to look up is Owatrol Oil https://owatrol.com/en/all-our-products/7936-owatrol-oil.html may be similar to the above treatment.

Owatrol can also be mixed with most oil based paints but won't penetrate quite as well.

Isambard

rust on items such as the exhaust, springs and shocks is not worth worrying about. Concentrate on any you see on body/chassis members , I can't actually see much in that category in your photos. Probably also worth keeping the brake lines rust free as this is an NCT fail.

corks finest

Toyotafanboi wrote: »

I dont think you'd ever clean that up properly to the point of where you wont see it coming back through.

I'd probably try to do a good job on the bits on the bodywork as that will be a problem in the future and let the running gear components go, they're too far gone to turn around IMO.

What is it? Something commercial anyway with the leaf springs.

Bloody salted roads

corks finest

KB22 wrote: »

businessdit wrote: »

Hi all,

I have a 2015 car with considerable undercarriage rust.
Looks like only surface rust, but I want to treat this now.
Was a north UK import... so pretty bad for the age i think.

Can anyone advise what i should do about this DIY?

If I remove as much as I can with wire brush and then spray a few coats with Schultz paint would that work? Any other products you would recommend?

If I can't remove all the rust does that mean that i haven't really tackled the problem. How much of the rust do i have to remove?

Don't want to cover it aesthetically and then still have the problem underneath with it rotting away.

Also do I need a primer before the Schultz is applied?
Any advice appreciated. Want a long term solution and reduce any damage done.

See pictures below:
https://ibb.co/DC5dcvb
https://ibb.co/xJFq9QW
https://ibb.co/QDfwGzt
https://ibb.co/nsMQ2xz

THANKS!

I have used this product on my classic.You don't need to paint after using,it leaves a visible film after proper application. As long as you remove loose rust, VACTAN will form a coating it can be left like that or painted over. Good luck,keep us informed!

Would the NCT ppl fail that if used on a car ie covering brake pipes etc?

JohnBoy26

Bilt hamber rust remover gel, when rust is removed apply two coats of bilt hamber electrox followed by a coat or two of bilt hamber epoxy mastic.

Apply a coat of bilt hamber dynax ub to finish.

Just do the chassis and the body. Don't do exhaust or other mechanical bits.

Shultz will only cover the rust and trap moisture and salt which will only lead to a worse problem down the road

KB22

Corks finest I have no idea about NCT attitude about this product. It will leave a " greyish/clear/opaque" coating, you can still see the treated area ! What I really like about this stuff is how easy it is to use . I have a son an officer in the Irish Navy he put me onto this . They use it and it is the main product for the US navy. Hope this makes sense.

Cee-Jay-Cee

Isambard wrote: »

rust on items such as the exhaust, springs and shocks is not worth worrying about. Concentrate on any you see on body/chassis members , I can't actually see much in that category in your photos. Probably also worth keeping the brake lines rust free as this is an NCT fail.

So long as the corrosion/rust is only on the surface then it will pass NCT.

NCT testers see this every day with the amount of UK/NI imports on the roads. I was recently shown the underside of a 2 year old Avensis and it looked like a 20 year old car underneath. The car was originally from Scotland and near the coast so the combination of salt from the roads during winter and sea air have the underside of it destroyed.

My own car was also from Scotland and had pretty bad surface corrosion/rust but has passed its last 2 NCT's. I keep meaning to clean it up and use body-shootz or whatever its called but haven't got round to it yet.

Isambard

Cee-Jay-Cee wrote: »

So long as the corrosion/rust is only on the surface then it will pass NCT.

NCT testers see this every day with the amount of UK/NI imports on the roads. I was recently shown the underside of a 2 year old Avensis and it looked like a 20 year old car underneath. The car was originally from Scotland and near the coast so the combination of salt from the roads during winter and sea air have the underside of it destroyed.

My own car was also from Scotland and had pretty bad surface corrosion/rust but has passed its last 2 NCT's. I keep meaning to clean it up and use body-shootz or whatever its called but haven't got round to it yet.

they have been spreading salt in the Republic for very many years now.

my3cents

Isambard wrote: »

they have been spreading salt in the Republic for very many years now.

But at nothing like the level they do in the UK. I know a contractor over there with a contract with a local council and there are a set of weather conditions that might mean its going to freeze that has his lads out on the road. They could be out everyday for a fortnight on the same road but here once would be the job done.

Cee-Jay-Cee

Isambard wrote: »

they have been spreading salt in the Republic for very many years now.

Not to the same level as in the UK. What is spread here is largely grit with a small % of salt as opposed to majority % salt in the UK.

zilog_jones

I used some Waxoyl (aerosol can) on some rusty bits underneath my car (from Norn Iron), have I made a terrible mistake?

Isambard

not the case, in Cork at least

my3cents

zilog_jones wrote: »

I used some Waxoyl (aerosol can) on some rusty bits underneath my car (from Norn Iron), have I made a terrible mistake?

Its great stuff, I used to use it a lot (much more commonly available in the UK) but its not really meant for high impact under body areas so you'll have to keep applying it. Waxoyl make a thick black tarry under sealer that is meant for under the car that where stones etc are going to get thrown up underneath. The thinner Waxoyl is meant to be sprayed into the hidden areas of the car like in door panels an sills.

https://www.amazon.co.uk/Hammerite-5092953-Underbody-Seal-2-5Ltr/ OK so its now called Hammerite underbody sealer with added waxoyl.

businessdit

OP UPDATE:

Right thanks for all the comments.

i have been now chatting to a fellah who is going to sandblast the whole undercarriage and then apply rust primer and then a few coats of Schultz. He says he can remove all trace of rust by sand blasting. I'm a little bit wary of this as afraid the sand might go into engine or we will weaken the car in some way by sand blasting.

Anyone have any opinions on this?

Thanks!

Isambard

sand blasting is quite severe. I'd be wary

Toyotafanboi

Cant imagine an effective way of doing that without stripping all suspension, undercarriage etc.

JohnBoy26

businessdit wrote: »

OP UPDATE:

Right thanks for all the comments.

i have been now chatting to a fellah who is going to sandblast the whole undercarriage and then apply rust primer and then a few coats of Schultz. He says he can remove all trace of rust by sand blasting. I'm a little bit wary of this as afraid the sand might go into engine or we will weaken the car in some way by sand blasting.

Anyone have any opinions on this?

Thanks!

Don't Shultz it. That stuff only accelerates rust when it cracks and it hides it until its too late.

JohnBoy26

my3cents wrote: »

Its great stuff, I used to use it a lot (much more commonly available in the UK) but its not really meant for high impact under body areas so you'll have to keep applying it. Waxoyl make a thick black tarry under sealer that is meant for under the car that where stones etc are going to get thrown up underneath. The thinner Waxoyl is meant to be sprayed into the hidden areas of the car like in door panels an sills.

https://www.amazon.co.uk/Hammerite-5092953-Underbody-Seal-2-5Ltr/ OK so its now called Hammerite underbody sealer with added waxoyl.

The hammerite stuff is not great tbh. It's black and stays soft for a few weeks then it dries out and begins to peel. Im not convinced it stops rust either, even in places it hasn't peeled off.

The clear stuff is very messy too. It's hard to apply(has to be heated) but is still very messy. It's not clear either, it's yellow really and doesn't last very long.

JohnBoy26

Isambard wrote: »

sand blasting is quite severe. I'd be wary

Not only that but it will strip any good rust protection off the underside. The rust primer will not be as good as the original factory electro dip rust treatment.

I'd just treat the rusty patches with bilt hamber and then underseal the whole underside with dynax ub.

JohnBoy26

Isambard wrote: »

they have been spreading salt in the Republic for very many years now.

Never seen a car from this island with the same level of rust as I've seen on some uk cars from northern england/scotland

my3cents

JohnBoy26 wrote: »

The hammerite stuff is not great tbh. It's black stays soft for a few weeks then it dries out and begins to peel. Im not convinced it stops rust either, even in places it hasn't peeled off.

I used it on a brand new trailer about 4 years ago and it certainly needs doing again but it really has protected it very well. I agree it dries and begins to peel.

I would certainly use it on a car IF I had ready access to a lift so I could reapply EVERY year. But thats never going to happen.

Kristopherus

Would the Hammerite be of any benefit to the crash bars around a lorry?

CJhaughey

I have used Tetrosyl Tetroseal paint on underbody sealant with some success, its very durable and is thick so it doesn't drip easily when applied.

Notch000

Dinitroil is very well reviewed as a protective barrier post stripping and teating the rust