My cars are thoroughly treated underbody, no problems MOTing but the tester usually notes remarks to the effect of underbody heavily greased etc, i suspect any knowledgeable potential buyer will regard those comments as a win, Landcruiser not the type of vehicle to appeal to white goods buyers anyway.

You're doing fine as you are, steel brake pipes i grease up same with exposed underbody aircon pipes (rear aircon) and any exposed fuel or other steel pipes.

Hopefully you're not using UB on rust already there, it will look nice at first but will start to peel off in due course, probably a couple of years.

My Landcruiser has separate ladder chassis which are poorly coated/painted new (same on all 4x4's apart from Amarok i understand), i've coated the entire chassis in marine grease and done the same with exposed inner sills which suffer heaviy weathering on these vehicles, all body and chassis cavities have been sprayed liberally with BH's cavity waxes.

What i've taken to doing is spraying the entire underside with ACF50 every year, it washes off of course in heavy weather areas so not a one off treatment but it does seep into all suspension parts and body crevices and helps keep sensor cables links brackets etc lubricated and working as well as repelling moisture, a 4 litre bottle will last several years of annual applications.

Some others on the LC forums have been trying chain lube as an alternative underbody spray, and that is something i may try myself when the ACF50 is all used up, there are some alternatives to ACF50 which i haven't tried.

Rustproofing does work, i've changed how i go about things over the years, what works for me miight be different for others.

My reasons are i'm not doing what some dodgy wealthy (poor before he became a) politician tells me about cars, or much else come to that, have every intention of my 19 year old Landcruiser seeing me out and my daughter carrying on the family tradition of saying no :-)

Edited by gordonbennet on 19/09/2024 at 12:34

I applied Dynax UB by brush on already rusted areas, but I cleaned any loose rust with sc***er and wire brush. This totally overhelmed me, I planned to complete this by one day, but it already takes me over 3 days. Applying by brush is very slow, but it’s not splash everywhere like by spraying. What worries me is the stuff is sticky after 2 days., wondering how long it’s taking to fully dry, probably all dust from the road will stick to the undercoated places , is that’s how it should be?

Yes it takes a while to dry, however the stink disappears a heck of a lot faster than Waxoyl.

I sprayed BH's products on and inside cavities via their excellent aerosols, i keep an old carpet and various sheets of cardboard to help protect the driveway from the numerous drips that happen.

The downsides of rustproofing eh, the job takes much longer than expected, is filthy (trust me waxoyling would have been far worse) and the dirt sticks to the undersides it doesn't dry fully hard for weeks and future underbody work may be horrible but generally if you've done the job right bolts and fastenings come undone rather than snapping off.

Part of the reason i've opted for an annual ACF50 spray over is because i can do the whole underbody in 20 minutes, product warmed and in a garden pressure sprayer such as one would use for weedkiller.

Old clothes overalls hat mask and goggles are a must and you'll still be covered in the muck when finished, even the pros look like they've done a 12 hour shift down a coal mine when the job is done.

I don't see why not, the only issue with full underbody spraying with some motor oils is that they can perish rubber bushes spring top mounts etc over time, thats why i don't use cheap engine oil for full underbody coating.

I chose ACF50 because i wanted this type of corrosion protection, seeping into crvices etc, www.mslmagazine.co.uk/tested-acf-50-corrosion-prot.../ I'm half way down my last 4 litre bottle and may well try chain lube next, Landcruisers need something that will creep because the chassis is large and there's numerous moving sensors underneath, ie rear air suspension level sensors that corrode badly and eventually seize and fail at eye watering cost, plus you need something sprayable to reach the body which is obviously mounted above the chassis, your CRV will be much easier to apply rust prevention due to the unitary construction.

Chain lubes vary too, some are more sticky than others, the stickier the better for corrosion prevention.

Well done for having a go, most people don't bother, its a bit of a rabbit hole this corrosion prevention lark, with new vehicles you would treat the vehicle much differently than one thats several years old with existing rust, each of us doing this have found our own methods that suit ourselves, i've modified my preferences over the years.

Whilst Japanese are IMHO one of the best long term bets in vehicles of all descriptions, they arn't that well coated underneath, Japan doesn't use salt for winter roads hence they don't have the rust problems we do.

edit, for cavity spraying you will struggle to beat Bilt Hambers cavity wax aerosols, they come with probes that are around 18" long, you can poke those in anywhere and you will hear and feel the 360' spray as you pull the probe towards you, i've not had a singe blockage using these products...but do try and blow the probe clean after use if you don't use the whole aerosol, it should be possible to use those probes to spray other products through, the diffuser at the end of the probe is excellent.

Edited by gordonbennet on 20/09/2024 at 07:32

Thank you Gordon for all your help, regret I hear all of this what you tell me before I started the job. Would you please advise me if covered nuts and bolts with Dynax UB will not be a problem for any future work to do, as could be difficult to fit in a suitable spanner size if the nuts will be gummed up with Dynax? Do you know if Dynax is safe for suspensions rubber bushings, should I remove this stuff from bushings where accidentally I touched up them? Thank you ????

Don't worry about the nuts and bolts, you could always slide a 6 sided socket over those that look heavily caked in the stuff while its still wet, but it will chip off with a sharp screwdriver if you need to get to them in due course..

BH's stuff is supposed to be fine on rubber bushings etc, also i've seen no deterioration of rubber bushes that get regularly soaked in ACF50.

Carry on matey, this rustproofing lark is a learning curve for all of us, we've had numerous discussions on the busier of the two LC forums on the subject, those of us who have tried various methods, including professional treatments with considerably different results, each tell our tales good and bad and learn from each other.

There's several disussions on the Landrover forums on the subject.

I can only speak of what works for me and my use, what i'm doing may not be ideal for others and their methods might well be better, because of the vehicle design i can drive the LC straight up onto 4 ramps, so my annual recoatings take a couple of hours from start to finish, others might prefer a more involved intiial treatment and only recoat every few years. I've seen pics where chaps have actually lifted the body off the chassis and shot blasted the chassis and affected body undersides back to bare metal.

Some others have really gone to town far more than me, taking anything up to a week of hard work attacking the rust, treating metal with rust converter, priming painting and then applying their chosen products on top, often their vehicles have been in a bad state when bought, cars that have lived in Scotland will be far more corroded from salt than mine was which lived a fairly gentle life in Southern England with an obviously well heeld previous owner, i took one look under mine at the motorhome sales centre where it hhad been traded in and bought it on the spot.

Should also add, some of the best rust prevention which almost no one doesnow (how many can't even be bothered to wash the topside, more money than sense) is hosing the salt off the undersides now and again during the winter, then once spring has sprung and the salt is gone after a few rainy days i give the undersides a good hosing down to shift any remaning salt residue, sometime run the a local ford a few times which gives the hidden parts of the chassis a good rinsing, you don't need a pressure washer for this (though i have one and a right angle lance) decent mains pressure is adequate with using a soft brush to get in the nooks, ie round the rear wheel arches.

Edited by gordonbennet on 20/09/2024 at 11:27