Dinitrol Vs Por-15 Underseal for EK9 - Opinions?


Turfy

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Dec 31, 2012
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462
Going Undersealing the Ek9 in the coming week or so,

Current plan is:-
Wire brush on 4" grinder get it all back.
Use the Rustoleums Rust Reformer,
then use zinc primer to finish
then use dinitrol underseal,
then use some sort of stone chip coating

inner arches will also be dinitrol cavity wax,

Im planning to Use Dinitrol but people have mentioned to me that POR-15 is also very good,
(POR-15 Video
)
Just wondering what people opinions are on here regarding these products? would you recommened anything esle? or a change in the workflow above?

Thanks
 
I wouldn't do any of the above, the method in the por15 video should only be used on components, anything that requires washing bare metal with water is a bad idea on bodywork.

If your surfaces are not rusty then don't wire brush them off, just use a degreaser to clean the surface,

If there are any rusty areas clean them up and use a epoxy primer (like the rustbuster stuff maybe)
then use the dinitrol 4941 underbody wax.

Stone chip should not be used as a final coating, it is designed to be a undercoat to be painted over with a proper top coat, it will be ineffective and probably flake if you use it on top of underseal / underbody wax
 
I am currently in the process of stripping the old underseal and going the POR-15 route. From my experience underseal will flake over time, will form pockets where water can collect and accelerate rust if anything. This is especially true if it is applied over ANY rust - which on a 15-18 old EK9 it almost always will be. The advantage of POR15 is that it really forms a rock solid barrier - I was amazed at how hard a surface it creates when I first used it! I will not be driving the car in the winter so I may not need as good a protection as some others and from my experience underseal has a great ability to hide rust, I prefer seeing where the car is rusting so that I can deal with it.
I however agree with what has been said above, don't wire brush the whole car even tho it would be miles quicker - you don't want to damage the paint where it is still present! Also, wire wheel is all nice and good but it will not actually remove the rust, I prefer using a worn flap wheel (worn so that it works very slowly) and take it back to bare metal. If the resulting panel wears through or is too thin I just cut it out and weld new metal in place - tedious but it will need doing sooner or later.
 
I wouldn't do any of the above, the method in the por15 video should only be used on components, anything that requires washing bare metal with water is a bad idea on bodywork.

If your surfaces are not rusty then don't wire brush them off, just use a degreaser to clean the surface,

If there are any rusty areas clean them up and use a epoxy primer (like the rustbuster stuff maybe)
then use the dinitrol 4941 underbody wax.

Stone chip should not be used as a final coating, it is designed to be a undercoat to be painted over with a proper top coat, it will be ineffective and probably flake if you use it on top of underseal / underbody wax

Agreed people go too far with the grinders tbh. Ul make the surface weak and make it more prone to rust.
 
I wouldn't do any of the above, the method in the por15 video should only be used on components, anything that requires washing bare metal with water is a bad idea on bodywork.

If your surfaces are not rusty then don't wire brush them off, just use a degreaser to clean the surface,

If there are any rusty areas clean them up and use a epoxy primer (like the rustbuster stuff maybe)
then use the dinitrol 4941 underbody wax.

Stone chip should not be used as a final coating, it is designed to be a undercoat to be painted over with a proper top coat, it will be ineffective and probably flake if you use it on top of underseal / underbody wax

@b16 mini
What about the factory underseal still on the underbody? would that be left in place? (28,000 mile ek9)
What epoxy primer would you recommend? (Stonechips)
Would you leave the dinitrol 4941 as the only layer underneath? Would you recommend anything?
What do people usually finish the underseal off with?
I have previously undersealed with schutz...?

I am currently in the process of stripping the old underseal and going the POR-15 route. From my experience underseal will flake over time, will form pockets where water can collect and accelerate rust if anything. This is especially true if it is applied over ANY rust - which on a 15-18 old EK9 it almost always will be. The advantage of POR15 is that it really forms a rock solid barrier - I was amazed at how hard a surface it creates when I first used it! I will not be driving the car in the winter so I may not need as good a protection as some others and from my experience underseal has a great ability to hide rust, I prefer seeing where the car is rusting so that I can deal with it.
I however agree with what has been said above, don't wire brush the whole car even tho it would be miles quicker - you don't want to damage the paint where it is still present! Also, wire wheel is all nice and good but it will not actually remove the rust, I prefer using a worn flap wheel (worn so that it works very slowly) and take it back to bare metal. If the resulting panel wears through or is too thin I just cut it out and weld new metal in place - tedious but it will need doing sooner or later.

@oifovo what is your workflow for undersealing your ek9? Products wise? What will you be doing in terms of POR-15 and why did you choose it over Dinitrol?
 
POR-15 has been slated on some car restoration forums as it can crack off, especially when used on areas that do not already contain rust.

You should steam clean the underside, if there is rust then wire wheel it clean, use a rust remover (I forget the brand name of the most popular) and then coat with epoxy - Lechlar is the best epoxy to spray and roller. You can also buy epoxy in rattle cans but make sure it is 2 component where you have to perforate the hardener at the bottom of the can. Then I'd roller on some 2k direct gloss white and, if needed, spray a coat of Dinitrol over the top.

Also, you are comparing POR to Dinitrol and that's not a proper comparison as POR is paint and Dinitrol is a form of wax.
 
@Turfy - I have never used dinitrol but I have used POR15 extensively on our off roader so I guess I'm sticking with what I know. The reason why I'm so anti underseal is that both my current and previous EK9s have been undersealed and both have major issues where the old underseal peeled off and created water traps. Now this could be simply because they just slapped it on to make it look good or otherwise did not follow the process - I don't know but I don't want to use anything that will completely cover the paint. The reason is that if it rusts I want to know - it's far easier to deal with rust while it's relatively contained, as opposed to peeling off chunks of underseal only to find completely rotten metal underneath. I am by no means an expert, I have painted the chassis on our Vitara with POR15 and the poor thing sees an insane amount of abuse but the paint is incredibely resilient. I don't use their degreaser I use break cleaner as it works and dries far quicker and also leaves no residue but I do use their metal prep which is basically a rust converter and then apply two to three coats of POR15. Also, if I was to buy an EK9 now which I'm considering given how their value is rising now and I'd like to have both a EK9 track car and OEM car to keep as an inverstment I would seriously not buy an undersealed car - may sound extreme but my experience has taught me that underseal can hide a multitude of sins and I'd rather spend extra on importing a fresh car than buying one that has underseal on it.
 
@oifovo When you say you like to know if rust is coming up on the underbody etc Does POR-15 (as it is a paint as such) allow you to see it coming up? ye i heard break cleaner is quite good!

Im pushing towards dinitrol, i was chatting to torque-gt who imported my ek9 and they highly recommend Dinitrol, would you clean off/remove oem factory underseal?

Main question still though, so i remove oem factory underseal i presume yes?
 
As far as I know Ek9 has no factory underseal. As POR15 is paint it will show rust much quicker, simply because the layer is much thinner. Underseal is always applied as a thick layer ( compared to paint anyway) and from my experience hides developing rust really well. I've used this a few times to my advantage when putting old sheds through MOT lol
 
For me it's bare metal, phosphoric acid, bonda zinc primer, underseal then stone chip. 2 coats of each and never had a problem. The bonda zinc primer is highly recommended by restoration guys and phosphoric acid can be bought on ebay
 
Just go with the dinitrol 4941, it's good stuff, it's not like the "underseal" that everyone is going on about
 
POR-15 is a rust encapsulator, so will hold it, but for how long? You could look at rust bullet as well if you’re going down that route (which I've used many times)

As mentioned before never ever put any type of underseal on a rusty surface as this just traps moister in and the rust will spread. You need to remove as much as possible or at least neutralise it, I use http://www.bilthamber.com/deox-gel or http://www.bilthamber.com/hydrate-80.

Then you can look at protective primer/coating, I just normally apply Rust Bullet over the clean bare metal after treating it with Bilt Hamber stuff, followed by their hard shell coating and them some underseal. You want to be careful with Rust Bullet though, I've got it on my skin and it takes about a week to come off and you’ll need to clean your equipment with 2K paint thinners/solvents
 
If your looking for epoxy primer I can get it mixed and sent out to you Niall, lechler 2k product

My method would be to sand the original finish under the car with P120 orbital paper , any rust spots you come across then take back to bare metal and treat. After whole surface is keyed and prepared 2K epoxy primer, sand that with P240 orbital and stone chip then, 2k direct gloss in NH0 as a final top coat
 
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