Undersealing a car - worth it or asking for trouble?

What car is it? The majority of modern cars are galvanised so it's pointless.

yeah most non-japanese cars from the last 15 years just don't rust in a significant way. undersealing is a waste of time

If your north of Manchester your milage may vary

Salted roads dont care if your cars galvanised.

I'm tempted to buy either the Bilt Hamper or Lanogard product for my BMW Z4 rear subframe unless I can get a reliable good mechanic to take it out , I get it powder coated then mechanic lines the diff up correctly and it's looking tip top with new Sachs shocks and shiny black springs
It's how do you coat the tricky bits to access?

The body under mine is fine but the other stuff down there is somewhat corroded. I think perhaps the car was parked on grass or mud a lot previously. The springs and non-alu swingarms are somewhat rusty, along with stuff like suspension alignment adjuster bolts and the steering rack linkage even though it was behind the under tray.

I am thinking I will get it coated for longevity.

2004 Volvo V70 owner here - galvanized bodywork but salt still has a go. It is expensive and time consuming to do it properly.

1. Remove rust mechanically followed with Jenolite/Fertan.
2. Few layers of zinc rich epoxy
3. Dinitrol over the epoxy
4. Bill Hamber in any cavities.

Anything less and you are trapping moisture/rust to do it's work unseen.
[url= https://i.ibb.co/WzmST9d/269-E61-AF-B72-C-4115-A713-E0-D597-E83-FB2.jp g" target="_blank">https://i.ibb.co/WzmST9d/269-E61-AF-B72-C-4115-A713-E0-D597-E83-FB2.jp g"/> [/img][/url]
[url= https://i.ibb.co/zS1GRw3/4-F3969-EB-1498-4800-BCDD-F33707-B79-A0-A.jp g" target="_blank">https://i.ibb.co/zS1GRw3/4-F3969-EB-1498-4800-BCDD-F33707-B79-A0-A.jp g"/> [/img][/url]
[url= https://i.ibb.co/HPSBvby/22-D4-FE3-F-0424-436-B-AD7-C-F57-F5250-B298.jp g" target="_blank">https://i.ibb.co/HPSBvby/22-D4-FE3-F-0424-436-B-AD7-C-F57-F5250-B298.jp g"/> [/img][/url]
[url= https://i.ibb.co/QPhGmbF/7-CE7-ED35-A936-48-F5-9-C41-9942529-E0504.jp g" target="_blank">https://i.ibb.co/QPhGmbF/7-CE7-ED35-A936-48-F5-9-C41-9942529-E0504.jp g"/> [/img][/url]

I've bought a high mileage XC90 that is going to get the same treatment.

Whenever doing brake work, or swapping winter/summer wheels over I give the suspension parts a bit of ACF50 attention. The actual underbody and wheel arches etc themselves on any half decent car in last 20 years shouldn’t really rust unless damaged.

half decent car in last 20 years shouldn’t really rust unless damaged.

Hello Northern England winters..... galvanized Volvo front suspension turret. Regularly washed out and owned from nearly new. Never damaged.
Sorted it then coated it as per the above post.
[url= https://i.ibb.co/PFPNMp5/5-F930-D3-D-679-A-42-A8-AAD4-F4950-AE79-FC9.jp g" target="_blank">https://i.ibb.co/PFPNMp5/5-F930-D3-D-679-A-42-A8-AAD4-F4950-AE79-FC9.jp g"/> [/img][/url]
[url= https://i.ibb.co/ZSsFDMp/5-AD743-F4-2-D65-4296-B9-E0-5224-FFAB2-DF0.jp g" target="_blank">https://i.ibb.co/ZSsFDMp/5-AD743-F4-2-D65-4296-B9-E0-5224-FFAB2-DF0.jp g"/> [/img][/url]

I do on a fresh import but they’re usually super clean underneath. A uk car that’s caked in muck and some sort of sealing already really needs to be cleaned off properly and inspected before putting anything new on.

galvanized Volvo front suspension turret

That's one for the "argh, my eye!" thread.

Yeah it's photos like the above that make me wonder. I'm north of Manchester by a fair bit and the council round here are on top of their road gritting. Also the forums suggest Ford have dealt with a lot of warranty issues on my model due to poorly applied underseal.

Might just get the pressure washer on it underneath more often and see how it looks after a few months.

Bare in mind it is a 2004 year with 200k miles on it so it suffered from rust long after lesser cars had long since been scrapped. Hopefully it's good for another 200k miles now.

What you need is a few decent oil leaks. It may or may not be a coincidence that my fully galvanized but 37 year old car seems a bit more rust prone since I made it completely oil tight. Looks like I'll be replacing the previously oil coated steel fuel pipes soon.
Can't decide on full length flexy pipes or cunifer? Hard pipes.

Is that a V40? Looks vaguely familiar? My 1998 V40 eventually had some rust on the leading lip at the inside of the rear wheel arch. There is a space where lots of muck and grit can accumulate. But on actual underbody rust (ie the vast expanse that isn’t wheel arches) have not seen a car rust there this century (either mine or a mates).
Just seen OP has a Ford. So underline what I said about quality brands… OP get yer underseal out now ;-).

This for the Mustang? If it's made it as far as needing an MOT without entering a field/crowd sideways , it's probably worth doing. If done right (like @RustyNissanPrairie's post earlier) then it can be worth it. As is usual with most things, the preparation is the key bit - no point undersealing on top of existing rust/corrosion. The ony downside I found was it makes future working under the car a bit messier as you're going to get covered in the underseal - it made working on the suspension and fuel and brake lines a messier affair than it should've been.

I had my Monaro cleaned and Dinitrol'd within a few weeks of buying it. In my case it was worth it: 14 years old, 57k miles in northeast England, and no underseal from factory (joys of being an Aussie market vehicle). Fairly essential as it was my daily car in all conditions including Scottish winters (I had it on all-season tyres). Preserve & Protect in Johnstone - how far north are you again @TheFlyingOx? Link detailing the process.

Before:

After:

Yeah it's the Mustang. Reading around I don't think they apply any underseal for the US or EU market but apparently decided it's a good idea for us. Done at port in Rotterdam before getting shipped to the UK and it seems it's a Friday afternoon job for the work-experience kid - lots of pics of underseal sprayed onto the exhaust and not much anywhere else.

I'm in Fife so not too far away from civilisation. The garage I've taken it to for the service is a muscle car specialist - he's currently race prepping a beautiful Dodge Viper - and he does underseal so I assume he would make it as easy as possible for himself down the line. Just not sure if it's needed. I'm assuming it's not cheap if done correctly/thoroughly.

Part of me thinks that lanoguard stuff looks like a better idea, less permeant, but also no black and gunky and impossible to see through. I've got a big tub of underseal and an MG Midget but decided that on balance the next owner if there is one would probably rather see the underside rust free than see underseal that could be hiding anything from a pristine car to filler and newspaper.

Part of me thinks that lanoguard stuff looks like a better idea, less permeant, but also no black and gunky and impossible to see through. I’ve got a big tub of underseal and an MG Midget but decided that on balance the next owner if there is one would probably rather see the underside rust free than see underseal that could be hiding anything from a pristine car to filler and newspaper.

Part of me thinks the same - underseal could be used to hide issues. Not just from next owner but from yourself too. My Monaro underside looked great 4 years later (with annual topups done by me) but for all I know it could be hiding anything. The only MOT advisory I had in my time with it was "Underside heavily undersealed" meaning they couldn't see any serious issues, but acknowledging that might be because they couldn't see past the underseal!

I've not undersealed my van as plan was (and partly still is) for a partial camper conversion on it. Last thing I want is the mess of working under it with underseal covering everything. However, given it's a Transit I really should apply something - perhaps Lanoguard is a better solution.

Part of me thinks that lanoguard stuff looks like a better idea, less permeant, but also no black and gunky and impossible to see through. I’ve got a big tub of underseal and an MG Midget but decided that on balance the next owner if there is one would probably rather see the underside rust free than see underseal that could be hiding anything from a pristine car to filler and newspaper.

I've been impressed with lanoguard so far. I can't comment on long term protection because it hasn't been on long enough but it's very easy and quick to apply and a small amount goes a long way.
I coated the underside of a long wheel base Vito in under an hour, used 2 litres and it's on good and thick, no drips and hasn't washed off so far I smelled funny afterwards though.

Yeah I am thinking that in less severe requirements Lanoguard or similar could be worth it. I mean it's not a 70s Landrover or anything and I don't live on a seaside cliff-top.

I smelled funny afterwards though.

The eternal reek of damp wool?

@a11y

That's the one

@a11y

Preserve & Protect in Johnstone

I follow their FB page. I was considering getting them to do my Citroen Relay camper, I converted it from new and should have done it straight away. It’s still looking pretty good underneath so I might get around to asking them for a quote.

@phil5556, I was happy with them. Nice folk for starters, good comms throughout with photos most days via WhatsApp (hence me having the pics above to share) and price seemed decent. Most importantly they did a good job: masked off bits like the exhaust where you don't want underseal to reach etc,. They do everything from rusty old MX5s (and rusty new MX5s...) to old Landys and vans.

Plus in a bizarre coincidence they're located 1/2 a mile from my childhood house

Avoid using Waxoyl - it's been left far behind nowadays, Dinitrol is where it's at as it dries to a nice dry almost plastic like coating but out of everything I've slathered under Landrovers/Transits and nowadays Volvos - zinc rich 2pack epoxy is the best single coating. It forms a tough impact resistant impervious coating with the zinc acting as a sacrificial. It does need an abraded grease/oil free surface for best results.

Cheers a11y - their FB page gives a good impression of them but always good to have an actual recommendation