How often should you underseal

[Roger Helsby]

I've recently bought a land cruiser and wish to keep hold of the vehicle a few years. How often should you protect and rust proof the vehicle with underseal? I've just been reading this feature is Dinitrol or Waxoyl the best solution? https://www.tiltrak.com/car-rust-proofing/

 

[diggerdave]

You'll find many different opinions. Your options range from a very basic 'wash and brush on waxoyl', through 'wash, wire brush, apply rust converter, paint, apply something like dinitrol with a spray-gun' to 'get it done professionally'.I've concentrated on the chassis, the inner wings and the rear axle.

Taking into account the value of my vehicle, which is pretty rough around the edges, I've always opted for the first option and try to do it once a year. Some will say that is the worst of all worlds because if you don't clean off the existing rust, all you are doing is sealing it in. However, I see the waxoyl as providing a barrier between the chassis and mud/road salt.

My chassis was in good nick when I bought the car 50,000 miles ago and it's still in good condition now. The rear axle has now had some welding on the turrets. The inner sills have now had to have some welding too, so the basic-waxoyl approach didn't stop them rotting (but they might have been a lot worse if I hadn't done anything).

In retrospect I might have spent more time over it and cleaned and painted before waxoyling. It wouldn't have taken much longer really.

 

[StarCruiser]

Underseal- never
Waxoyl- only if completely 100% water, damp, humidity free, in other words no rust to slight surface rust, as it will hold water in.
There’s quite a few guys on here have used Krown. It’s amazing to see it applied to a sopping wet underside and see it make the water run off like rain. I’ll be having a top up this year which is 3 years since having it done initially. Have a look. Mention the club.

 

[Towpack]

The Krown stuff looks like and has very similar properties to Corrosion Block which is a non drying oil based product which displaces water and also claims to stop the corrosion process. I think the key to success with products that dry and harden is to remove ALL rust first and, as SC has mentioned, make sure the surfaces are completely dry.

 

[nick_the_fish]

We had our's professionally done by JP classics who took off what little rust was on there and sprayed the whole truck, inc cavities with Dinitrol. That was 7 years ago, I monitor it every year but only just starting to find spots that need a re-coat, which i'll touch up with Dinitrol as and when I need to.

I agree with Dave, it's a personal choice based on how much you have spent on the truck and what you have planned for it. We've spent a s*it load on our truck over the years and plan to do a lot of travelling in her as the years go by, so we were happy to bear the cost for the peace of mind of good protection.

 

[Finiterex]

I've gone with full clean back, all rust repaired, upol raptor and then will be doing annual clean and spray with ac50. I've used ac50 on bikes and it's amazing at keeping muck and water away. Combined with regular cleaning it works wonders. Just my two cents.

 

[Shayne]

I have high hopes for this https://www.frost.co.uk/zinga-zinc-coating-500ml-aerosol/ followed by this https://www.frost.co.uk/eastwood-extreme-chassis-black-satin-397g/ though the Krown treatment was done first in acceptance that it took me 5 years to get around to the job on my first truck . But no regrets because the Krown gets places i will never get to with a wire brush .

 

[Towpack]

That looks much like this stuff https://www.ebay.co.uk/itm/Action-C...027988&hash=item1ed6ff8d03:g:iIAAAOSw9P1dWqEz ...which Ive used a few times and is about as good a treatment as you can get from a can but they'll never be as good as proper hot dip or electrogalvanising,

 

[Finiterex]

That looks much like this stuff https://www.ebay.co.uk/itm/Action-C...027988&hash=item1ed6ff8d03:g:iIAAAOSw9P1dWqEz ...which Ive used a few times and is about as good a treatment as you can get from a can but they'll never be as good as proper hot dip or electrogalvanising,

All the 'zinc in a can' products are basically etch primer with zinc. Yes they will help deter rust assuming you have a good clean surface to start with... But nope it is not the full chemical reaction involved in galvanising. The process requires heat... Hence hot dip.

 

[Shayne]

Zinga claim 96% zinc and if the weight of the tin is anything to go by i'd believe it . It goes on very thick .

Must be a couple of years since i put some on the mrs truck then made it black with some non specific halfords spray , i will post a pic when shes back , right now your guess is as good as mine how it looks

 

[Shayne]

 

[StarCruiser]

View attachment 158922

Can’t fault that Shayne.
I often wondered about using Galvafroid seeing as I’ve got a tin in the garage. I know what you mean about the weight.

 

[Shayne]

Given how little effort i put into it with a wirebrush beforehand and accepting the shocks still looked good when i did it or else i'd have painted them as well i'm regretting while looking at that pic not protecting the zinga with proper chassis paint . And i'm gutted that i didn't use the same on my 90 after exhaustively removing all the rust because that Omnicote stuff didn't last well .

 

[Finiterex]

Given how little effort i put into it with a wirebrush beforehand and accepting the shocks still looked good when i did it or else i'd have painted them as well i'm regretting while looking at that pic not protecting the zinga with proper chassis paint . And i'm gutted that i didn't use the same on my 90 after exhaustively removing all the rust because that Omnicote stuff didn't last well .

Looks like a pretty good job on the wife's truck mate!

 

[RNS]

I've recently bought a land cruiser and wish to keep hold of the vehicle a few years. How often should you protect and rust proof the vehicle with underseal? I've just been reading this feature is Dinitrol or Waxoyl the best solution? https://www.tiltrak.com/car-rust-proofing/

I do it once a year with rust-stop. It is reasonable for the area where I have to use winter tires from November till April. The anti-ice reagents are being used on the roads in winter kills body, frame and even rear axle.
http://www.ruststop.ca/

The pics below: just one week after car-wash (( Regular rustproof is necessary.

 

[Finiterex]

I do it once a year with rust-stop. It is reasonable for the area where I have to use winter tires from November till April. The anti-ice reagents are being used on the roads in winter kills body, frame and even rear axle.
http://www.ruststop.ca/

The pics below: just one week after car-wash (( Regular rustproof is necessary.
View attachment 158936
View attachment 158937
View attachment 158938

Looks like the car came off worse than the 90!!

 

[RNS]

Looks like the car came off worse than the 90!!

I posted the pics to show the layer of dirt on the car after one week from carwash.

As for the car behind... just a little bit

 

[alby79]

I've gone with full clean back, all rust repaired, upol raptor and then will be doing annual clean and spray with ac50. I've used ac50 on bikes and it's amazing at keeping muck and water away. Combined with regular cleaning it works wonders. Just my two cents.

How did you find raptor as an underseal mate - has it held up OK?

 

[MODVRS]

The sills, chassis and axle turrets rotted from the inside out on mine so my advice would be to spend as much effort getting stuff inside these bits as coating the outside. Removing any lumps of rust and mud in there is a good idea. There are numerous drain holes in the sills, doors, shock absorber mountings and axle turrets, keeping these clear at all times is vital. As everybody else says, thick black underseal is worse than useless as it traps water and the first you'll know is when you can put a screwdriver through the metal.