Underseal

[Otter Spotter]

Whilst getting Otter Spotter the van mot‘d the examiner advised me to get it undersealed. It’s currently clean as a whistle but he says that Sevel vans tend to rot first in the sills and Jacking points and good under sealing will protect the metal.
The question I have is what underseal should I use ? Should I consider raptor paint or what ?

 

[Lenny HB]

Shouldnt need it, your van is galvanised.

 

[Nigel L]

I’ve often thought about putting some protection on the underneath whilst the van is relatively new.
Had thought about waxoil, although has been a number of years since have done any waxoiling, but open to other (better?) alternatives

 

[Stag man]

Hi Otter Spotter, not sure how old your PVC is but personally speaking I would not under seal any metal-based vehicle other than from brand new. Underseal can look ok on the surface but hide a load of nasties underneath especially if it slightly parts company from the component it’s sprayed on and allows water to track between (the water never dries out)
Also, as above, if your van is galvanised underneath (all of it.....) then under sealing is an unnecessary expense

 

[Stag man]

I’ve often thought about putting some protection on the underneath whilst the van is relatively new.
Had thought about waxoil, although has been a number of years since have done any waxoiling, but open to other (better?) alternatives

Waxoil is good.
other good quality wax-based clear coats are ok too

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[POH]

How much would it cost to underseal my 3 month old van .

 

[Stag man]

How much would it cost to underseal my 3 month old van .

Not a lot if you diy
Most seals come in big aerosol cans so fairly easy to apply
plus at 3 mths old your van is worth doing
Just a mucky job cleaning a bit of road grime away from the chassis/jacking points and spraying the sealer on

 

[Westbarn1]

I use this <Broken link removed>

 

[Guigsy]

My 2007 x250 Ducato did start to get a bit of rust before I sold it. I had the sill done on one side under the driver's door as it was bubbling up. Not sure if it was rising rot from the jacking points or from stone chips from the wheels. Underneath was solid, despite all the holes that had been drilled in it. All the rails looked like new. The only other bits that looked nasty were some of the brackets under the bonnet like the fluids holder, and the towbar metalwork, which was so thick it'd take a tank shell.

 

[Pops 1]

Funnily enough I was under my 14 year old Ducato based van today greasing up the electric step and thinking to myself that it was remarkably clean and rust free on the chassis. It’s never had a drop of under seal on it and in my opinion doesn’t need it either.

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[Otter Spotter]

Hi Otter Spotter, not sure how old your PVC is but personally speaking I would not under seal any metal-based vehicle other than from brand new. Underseal can look ok on the surface but hide a load of nasties underneath especially if it slightly parts company from the component it’s sprayed on and allows water to track between (the water never dries out)
Also, as above, if your van is galvanised underneath (all of it.....) then under sealing is an unnecessary expense

3 years old with 19500 on the clock

 

[TheBig1]

Technology has moved on and proven underseal and many other coatings to be a false "fools" economy as the box sections rust from the inside unseen due to the coatings. A more modern and well thought of solution is fluid film and copies of it. Gromett did some tests on his old van and shared the findings and photos

 

[Richard n Ann]

I waxoyled under my defender... big mistake, it dries and peels off after 2 years with rust underneath. Best thing I've use so far is lithium grease in aerosol cans. I greased my mum's vauxhaul nova horn bracket and 12 years later when she was selling it it was perfect under the muck and grease, it never sets and repels moisture. Also sprayed our scooter rack with it 6 years ago

 

[Stealaway]

Not only are most modern vehicles made from pre plated steel they are completely submerged in in a paint primer before applying a top coat. Underseal is old fashioned these days.

 

[Gromett]

Technology has moved on and proven underseal and many other coatings to be a false "fools" economy as the box sections rust from the inside unseen due to the coatings. A more modern and well thought of solution is fluid film and copies of it. Gromett did some tests on his old van and shared the findings and photos

I did a test of various coatings and the 2 most effective were high zinc primer and Fluid Film.

2 days ago I uncovered a sheet of steel I had sprayed with high zinc primer that I used to replace the sills on my van. I had forgotten about then as it was 3+ years ago. I showed it to Jim as even I was extremely surprised by how well it held up.
It had bird crap on it, mud, leaves and ivy over it. I cleared it off and it was rust free apart from a single bit where I presume my thumb had been while spray it.
I had cut numerous long strips to do the inner and outer sill on the van, sprayed them with the zinc primer than welded them in place. The excess was put under my trailer. I sold the trailer last year and didn't see these due them being covered in mud.
So it was a pretty brutal test.

Fluid film was almost as effective but in a car it would need regular touch ups in places like the wheel arches where water spray can wash it off.

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[ChrisL]

I think Dinitrol is what most car restoration companies use, it is a time consuming and messy job but is apparently very good, according to friends in the trade, if the correct prep and application is followed.

The link shows the application process on a Land Rover.

 

[Richard n Ann]

I think Dinitrol is what most car restoration companies use, it is a time consuming and messy job but is apparently very good, according to friends in the trade, if the correct prep and application is followed.

The link shows the application process on a Land Rover.

My mate put it on his 2003 Navara, I said at the time that smells suspiciously like waxoyl ... Sure enough 2 years later it's falling off with rust under it. Might be ok on a brand new vehicle but as soon as the dreaded tin worm gets hold it's worse than useless.

 

[Richard n Ann]

Lanoguard sounds like it might be ok, looks like it's a type of grease

 

[ChrisL]

My mate put it on his 2003 Navara, I said at the time that smells suspiciously like waxoyl ... Sure enough 2 years later it's falling off with rust under it. Might be ok on a brand new vehicle but as soon as the dreaded tin worm gets hold it's worse than useless.

Obviously I don't know how your friend applied it, but proper prep is essential, that includes using the oxide converter before applying the wax coat otherwise you're not going to get the proper results. It's also worth mentioning that Waxoyl and presumably the Dinitrol wax coat has to be reapplied every few years, the whole point of the Dinitrol system is to convert the rust into a stable barrier against further corrosion before covering it in wax.

Check out there website for further information.

Rust Treatment | Corrosion Protection | Windscreen Repair | DINITROL UK

DINITROL® UK rustproofing, rust treatment, Corrosion protection, underbody, windscreen replacement, vehicle body filler repair cars automotive aftermarket

www.dinitroldirect.com

 

[Augusta08]

I put Dinatrol on my Mini about 20 years ago

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[Richard n Ann]

Obviously I don't know how your friend applied it, but proper prep is essential, that includes using the oxide converter before applying the wax coat otherwise you're not going to get the proper results. It's also worth mentioning that Waxoyl and presumably the Dinitrol wax coat has to be reapplied every few years, the whole point of the Dinitrol system is to convert the rust into a stable barrier against further corrosion before covering it in wax.

Check out there website for further information.

Rust Treatment | Corrosion Protection | Windscreen Repair | DINITROL UK

DINITROL® UK rustproofing, rust treatment, Corrosion protection, underbody, windscreen replacement, vehicle body filler repair cars automotive aftermarket

www.dinitroldirect.com

Probably wasn't prepared to the required standard as he paid somebody to do it. Must be a right time conuming faff unless the vehicle is stripped down fully under restoration.

 

[Gromett]

I think Dinitrol is what most car restoration companies use, it is a time consuming and messy job but is apparently very good, according to friends in the trade, if the correct prep and application is followed.

The link shows the application process on a Land Rover.

I used various Dinitrol products and was initially impressed. But after 3 years it had rust around then under the dinitrol treated areas. Seemed no better in the long run than waxoyl or underseal.

If you have a totally rust free vehicle and can treat everywhere then I am sure it is effective. But once rust has already started I don't rate Dinitrol much. It is better than things like kurust by quite a margin but that isn't hard to be honest.

If rust has already started it I my opinion that you need some oil based liquid that doesn't set, creeps and self repairs.

Lanoguard sounds like it might be ok

It's seems to me to be the same as Fluid film. Based on Lanolin.