Author Topic: Underbody surface rust Mk7  (Read 1440 times)

Offline AHAgolf

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Underbody surface rust Mk7
« on: 11 April 2022, 19:15 »
Hi all, I’ve recently bought a 2016 GTI and had it up on a set of ramps and found lots of surface rust on most of the suspension parts, is this normal? 6 years old and 45k miles. I’ve treated it all with Bilt Hamber Dynax UB which should provide some protection as well - anyone able to recommend other options? Thanks.

Offline willni

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Re: Underbody surface rust Mk7
« Reply #1 on: 13 April 2022, 11:46 »
Mine was the same when I got it 2019 car and I got it early 2021. Trying to find the time to get it on a ramp and sort it out.

Some rust eliminator / neutraliser onto the affected areas is always a great starting point, so I'd try and knock it back with a wire brush first then put BH Hydrate 80 on if you can, then just continue on with your Dynax UB.

How do you find the Dynax UB? I'm currently using XCP Rust Blocker.
WillNI the GTI Guy

Mk5 Edition 30 OEM+ & Mk7.5 GTI PP

Follow my 7.5 build on the forum https://www.golfgtiforum.co.uk/index.php?topic=287596.msg2638666#new or on Instagram https://www.instagram.com/willy_gti7.5pp/

Offline AHAgolf

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Re: Underbody surface rust Mk7
« Reply #2 on: 13 April 2022, 19:18 »
Thanks, not heard of Hydrate 80 so will look into that. I’ve used Dynax UB on a couple of other cars and it’s amazing stuff, it can be applied to rusty surfaces (not loose stuff) and the rust almost completely disappears. It leaves a thin wax like coating. One car I bought had some surface rust, I sprayed it all and two years later it looks perfect still. Helps if you can get good access of course.

Can’t believe yours was going rusty at just 2 years! 😳

Offline willni

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Re: Underbody surface rust Mk7
« Reply #3 on: 14 April 2022, 17:55 »
Thanks, not heard of Hydrate 80 so will look into that. I’ve used Dynax UB on a couple of other cars and it’s amazing stuff, it can be applied to rusty surfaces (not loose stuff) and the rust almost completely disappears. It leaves a thin wax like coating. One car I bought had some surface rust, I sprayed it all and two years later it looks perfect still. Helps if you can get good access of course.

Can’t believe yours was going rusty at just 2 years! 😳

Must give the Dynax a go then, the XCP just doesn't last as well as I'd like.

In fairness the previous owner of mine lived by the sea, nothing can protect something from the sea air unfortunately.
WillNI the GTI Guy

Mk5 Edition 30 OEM+ & Mk7.5 GTI PP

Follow my 7.5 build on the forum https://www.golfgtiforum.co.uk/index.php?topic=287596.msg2638666#new or on Instagram https://www.instagram.com/willy_gti7.5pp/

Offline AHAgolf

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Re: Underbody surface rust Mk7
« Reply #4 on: 16 April 2022, 17:11 »
Thanks, not heard of Hydrate 80 so will look into that. I’ve used Dynax UB on a couple of other cars and it’s amazing stuff, it can be applied to rusty surfaces (not loose stuff) and the rust almost completely disappears. It leaves a thin wax like coating. One car I bought had some surface rust, I sprayed it all and two years later it looks perfect still. Helps if you can get good access of course.

Can’t believe yours was going rusty at just 2 years! 😳

Must give the Dynax a go then, the XCP just doesn't last as well as I'd like.

In fairness the previous owner of mine lived by the sea, nothing can protect something from the sea air unfortunately.

Living by the sea does have some disadvantages!

Offline joe6

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Re: Underbody surface rust Mk7
« Reply #5 on: 20 April 2022, 09:57 »
I had a small amount of surface rust on one rear suspension arm on my 2019 (bought it late 2020) car but it spent its first year in Scotland so should probably expect it. Not because of the Scots just the salt  :grin:. Treated it with jenolite rust remover and coarse wet and dry - took a while but had good access - three coats of hammorite and then waxoil. No recurrence after two winters so seems worthwhile to spend the time.

Took about 6 years before any rust appeared on my mk6 but not subject to a harsh environment and regularly hosed down underneath but not jetwashed.
« Last Edit: 20 April 2022, 10:00 by joe6 »
Mk6 GTI Carbon Grey, 2010 Bluetooth and voice fitted, a few VCDS mods still a comfortable family car. Red Scirocco 2011 twin charger stage 1 - enjoyable drive now gone.  White 2016 Polo GTI (roller skate on steroids) replaced with an Indium Grey 2019 7.5 GTI PP.

Offline AHAgolf

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Re: Underbody surface rust Mk7
« Reply #6 on: 20 April 2022, 15:56 »
My car has spent most of its life in Scotland or North Yorkshire so I suppose it’s been subject to worse/wetter weather up until I bought it. I hadn’t considered that. I’ll be keeping an eye on it and hopefully will be better from now onwards.

Offline Sootchucker

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Re: Underbody surface rust Mk7
« Reply #7 on: 25 June 2022, 16:58 »
This is how my GTI MK7.5 looks after 4 years (May 2018 car), but then I do keep on top of it. There is still minor rust around the leading and trailing edges of some of the pressed steel components, but overall not too bad. These were taken last year, but on a clean up 2 months ago still looked exactly the same.



2018 GTI DSG 230ps 5 door, Indium Grey - 19" Brescia alloys, Art velour interior, Dynaudio, DCC, keyless, wireless charging, adaptive headlights, Lane assist, side assist, rear assist, dynamic traffic sign display, heated Windscreen, rear view camera, Winter Pack

Offline joe6

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Re: Underbody surface rust Mk7
« Reply #8 on: 29 June 2022, 13:56 »
Still looks new. Are you sure it has been out in the wet :grin:
Mk6 GTI Carbon Grey, 2010 Bluetooth and voice fitted, a few VCDS mods still a comfortable family car. Red Scirocco 2011 twin charger stage 1 - enjoyable drive now gone.  White 2016 Polo GTI (roller skate on steroids) replaced with an Indium Grey 2019 7.5 GTI PP.

Offline theminty1

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Re: Underbody surface rust Mk7
« Reply #9 on: 04 July 2022, 13:15 »
This is how my GTI MK7.5 looks after 4 years (May 2018 car), but then I do keep on top of it. There is still minor rust around the leading and trailing edges of some of the pressed steel components, but overall not too bad. These were taken last year, but on a clean up 2 months ago still looked exactly the same.



Thats amazing for the age of the car, so is there any protection on the underbody?