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Underbody rustproofing or sealing - Ebob

I have an 08 Avensis which I have owned for a year put 20k on so far and has been o Good car, just flown through its MOT.

When I bought it I checked the MOT and all was good only brakes tyres lamps etc.

I've been looking at avensis' for someone else and it appears that a lot of them have fails or advisories for corroded brake lines, wishbones and general suspension corrosion.

I always thought this was something these days which only affected cars of over about 15 years old.

So I'm thinking of trying to do some rustproofing of key areas so I don't get future problems.

I have seen hammerite with waxoyl although somebody who was s mechanic in the 80s said they used to use a sealer however water would seep underneath and rust and bubble and make it worse. Is this the case for this product?

Also I have seen Dinitrol which looks good but not as easy to apply, it's also quite expensive.

Given my car isn't actually corroded yet I just want something to boost the cars original protection and keep it at bay.

I want something which is fairly cheap and easy to apply

Also how often is it required to reapply this stuff?

Edited by Ebob on 06/02/2018 at 09:52

Underbody rustproofing or sealing - John F

a lot of them have fails or advisories for corroded brake lines, wishbones and general suspension corrosion.

A bit of superficial brake pipe corrosion is a favourite MoT failure. Four years ago I bought an 8yr old Audi, and it already had a history of 'brake pipe corrosion' failure next to a front wheel! My 38yr old TR7 brake pipes are original.

So I'm thinking of trying to do some rustproofing of key areas so I don't get future problems.

Good thinking.

I want something which is fairly cheap and easy to apply

Take each wheel off and grease the fuel and brake pipes (or Hammerite if you are feeling flush). Brush clean and paint the wishbones and springs with old engine oil, and anywhere else that looks vulnerable. Do it in summer after all the salt has been rinsed off - efficiently at the same time as an oil change if it needs one.

Also how often is it required to reapply this stuff?

If more than ten years old and used a lot, annually. Triennially if you clean, prepare, and use decent paint.

Underbody rustproofing or sealing - madf

Waxoyl washes off easily. Dinitrol does not and performs far better in tests and in real life. If you buy several spray cans of Dinitrol 4941 (for underbody as opposed to cavity ) sealing, there are discounts - see ebay for cheapest prices.

I keep our 2004 Yaris perfect underneath using Dinitrol every 3-4 years...Underneath is rust free. (As is the exhaust - but using heatproof paint)

Edit Dinitroled the underneath of a 2004 VW Sharan where all teh paint had vanished around the boot floor and rear suspension pick up points.. Used a pit. Took 4 cans and 90 minutes.

Edited by madf on 06/02/2018 at 11:52

Underbody rustproofing or sealing - Ebob

Thanks for the input.

How much preparation is involved before applying Dinitrol?

If it's quite a lot of work I might use oil.

Does Dinitrol attack rubber or do have to be careful about getting on bushes or anywhere else?

Underbody rustproofing or sealing - hardway

I had a Talbot Horizon in to the garage for work a few years ago,

put it inside and locked up for the day,

Anyway open up next day and was struck by a line on the floor either side of the car under the sill!

A quick bit of investigation revealed it looked/smelled like old sump oil!

Anyhoo it was in for Mot worked and if I recall it needed a brake lamp bulb or similar small stuff.

Which I'll admit was a bit of a shocker as these were rust buckets,

Real cheese graters underneath.

So owner turns up and he's pleased with the little I charged him but before he drive off I'm like "what's the thing with the wierd oil leaks"?

And he states it's an old trick from where he comes from,

One of the Skandinavian countries,Can't recall which one but it really snows up there.

They spray into the sill cavities with oil that's been drained from the sump during servicing.

Now this car was old back then and I'd take a bet that barring accidents it's still on the road now,

And as I stated they were rust buckets,

All I had to do was get a Mot failure in and my rent was paid for a month.

All he had to do was keep spraing the oil in.

And It's not a messy as I'm making out here.

Just a few drip/drops on my clean garage floor.

You wouldn't have noticed it out on the tarmac.

Now that to me is both preventive maintinance and recycling!!

Underbody rustproofing or sealing - hardway

Oh and one other thing a good few year back there was a rust treating workshop opened up near me.

Big advertising and wondeful guarantees for what seemed like dream amounts of time.

Weel they went bust,

Sued by so many that was it for this still quite famous product.

And lastly on this ramble a note of sanity.

Unerstand this

you only get rust where there is water.

Anywhere water can sit it WILL rust.

Not just in badly designed traps in body work or mechanicals if there's mud on say a wheel wells it clings and makes this neat little water trap.

wheel arches are prime spots.

wing tops............etc etc etc.

Just typing this in and I'm thinking the only part of any car that I haven't wellded up after a rust attack is the roof!

And I couldn't tell you how many cars I've had to weld in my time.

These days you'd think that's a thing of the past?

Just go looking under any older Transit.

Buckets.

Not like some/one Talbot Horizon I can remember!!!!

Old engine oil huh?

Underbody rustproofing or sealing - Ebob

Ye I bet in scandavia there's loads of salt in the roads all the time.

In the summer I think I will give the underside a quick rinse with the hose and paint some waxoyl or motor oil. If it can protect against the harsh Scandinavian winter should be good enough.

Dinitrol looks much better but I'd need to rent a steam cleaner and it's expensive I want something that's cheap and easy.

If any problem areas do develop I might clean with water and engine degreaser and put a bit of Dinitrol on just the problem area.

Edited by Ebob on 06/02/2018 at 20:59

Underbody rustproofing or sealing - liammcl

tbh, I just paint mine... box standard black paint. (whatever I have about)
scratch the rust off, brake clean it, maybe the galvanized welders spray on the hard to get interior places.

or poundlands roof and gutter sealant and then paint , if it was taking a hammering from the road (eg arches)

just gotta be a membrane to stop scratches and water getting to the metal..

Liam

Edited by liammcl on 07/02/2018 at 02:52

Underbody rustproofing or sealing - skidpan

They spray into the sill cavities with oil that's been drained from the sump during servicing.

Old sump oil contains acids that result form the combustion process and moisture. Can you honestly think of a better combination to actually create rust?

All he had to do was keep spraing the oil in.

And It's not a messy as I'm making out here.

Just a few drip/drops on my clean garage floor.

And then some poor guy on a motorcycle comes along on a wet day, hits an oil patch and possibly dies. Not a situation that should be created willingly.

Buy the right stuff if you want to rust proof your car.

Underbody rustproofing or sealing - galileo

Ye I bet in scandavia there's loads of salt in the roads all the time.

In the summer I think I will give the underside a quick rinse with the hose and paint some waxoyl or motor oil. If it can protect against the harsh Scandinavian winter should be good enough.

In Scandinavia studded tyres are very popular, which give good grip on snow (watch World Rally Swedish special stages to see how much) so maybe they just plough the snow smooth instead of using salt?

Underbody rustproofing or sealing - sandy56

Norway certainly do not salt their roads. Every motorist has to change to winter tyres before winter sets in. If you are caught without them on then you will get a big fine and your insurance will not be valid.( not studded tyres).

You only need studs for very bad conditions and you better not get caught using them on tarmac- a huge fine!

Studded tyres have been used on winter car rallies for decades.

 

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