DINITROL - which one to use?

[Andrew Prince]

Guys, this is probably a thick question but which model/grade of Dinitrol should I get (using the Club Discount)? Basically I am looking for something to use for a quick treatment of any flash rust underneath my LC. Basically something to have on hand when I'm working under there and come across a bit of surface rust, so I can give the rust a quick scrub with a wire brush and then spray/paint something on the area to treat and form a protective layer. I have been doing this up til now with an aerosol can of wayoyl but Dinitrol sounds better.

When I look on the Dinitrol website, everything sounds much the same - it all treats rust and forms a protective barrier layer. Some grades are for cavities and others are for flat surfaces (I imagine this relates more to the application than the stuff inside the bottle, which presumably doesn't know the difference between a cavity and a flat surface?). I certainly don't want to have to use 5 stages of treatments - if so, I'll stick with the waxoyl which does an ok job, if a bit messy....

Any advice appreciated

EDIT: I was informed that I'd posted in the wrong place and no-one could reply. Oops, apologies for that! I've moved to the Technical FAQ where hopefully it's of more use. Thanks for the PMs Adrian and Chris

 

[Andrew Prince]

Ok, the feedback I've got so far is that RC900 looks like my best bet. Am I correct in understanding that the RC900 attacks the rust and forms an impermeable (corrosion-proof?) layer? This layer can be left as is with no ill-effects or over-painted?

If so, this sounds like the answer for me

 

[Scott]

Ok, the feedback I've got so far is that RC900 looks like my best bet. Am I correct in understanding that the RC900 attacks the rust and forms an impermeable (corrosion-proof?) layer? This layer can be left as is with no ill-effects or over-painted?

The RC900 is perfect for what you need, but I wouldn't like to leave it just at that, in my opinion it's more like a first stage treatment, and not a long term 'out in the elements' stand alone finish. I'd overpaint it with some underbody wax, stonechip or cavity wax depending on where the rust is. All of these are available in aerosol cans for ease of use, and can be bought in kit form for a reasonable price.

Get a couple of cans of RC900 and see what you think. If your planning on spraying it in box sections/cavities, then the aerosol spray extension nozzle will be handy, but the can won't last that long as the nozzle has four holes (@ 90 degrees to each other), and the can empties quickly.

The RC900 doesn't take long to dry, so when you find some rust you can give it a quick brush and spray it. Once the RC900 has dried, you can then spray over the area with a wax, or stonchip, and be happy that it'll be well protected for a few years to come.

I did the whole underside of my 80 with the 1ltr air line cans and spray gun (motorhome size kit), I think I got through 10 cans of RC900 in the process, (I bought the 12 can multi-buy pack). So far I'm very impressed with the finish. Feel free to dive under the truck at Lincomb, and see what you think.


Cheers.

 

[Andrew Prince]

Thanks for that, Scott Exactly what I'm after! Did you spray the wax on top of the RC900 and what is the finish like in terms of toughness? I am thinking along the lines of painting various bits and bobs with POR-15 as and when I remove/refurbish them (think like cotnrol arms, ARB etc). The reason for POR-15 is that it sounds like the toughest stuff out there, so paint once and it should be good "forever".

Cheers,

 

[Scott]

Thanks for that, Scott Exactly what I'm after! Did you spray the wax on top of the RC900 and what is the finish like in terms of toughness?

I did, I sprayed the RC900 first, followed by the black underbody wax, and then finally a coat of stonechip in the required places. So far the coating seams to be standing up perfectly fine, none of it has pealed, no stone chips or scrapes. It hasn't had too much abuse yet, I applied it in november and it's only had road and dirt track use since. The real test will be desert conditions. The finished appearance looks like a factory finish in my opinion. So far, I'm very pleased with the dinitrol products, and this is the second vehicle I've used them on. The first vehicles finish is still in really good condition and that's been on there for over a year.

I am thinking along the lines of painting various bits and bobs with POR-15 as and when I remove/refurbish them (think like cotnrol arms, ARB etc). The reason for POR-15 is that it sounds like the toughest stuff out there, so paint once and it should be good "forever".

The POR-15 also sounds like a tough, quality finish, and if applied with a brush it should be quite a thick coating. One thing to consider with POR-15 is that it's a three stage process, first you apply a coating of "metal ready", followed by the POR-15, and then finally a coating of chassis paint as the POR-15 isn't UV stable and can degrade overtime, unless over painted.

If your decision isn't too time critical, then have a crawl under the 80 at Lincomb and you can judge for yourself if the finish is what you'd like for yours.

Cheers.

 

[Andrew Prince]

One thing to consider with POR-15 is that it's a three stage process, first you apply a coating of "metal ready", followed by the POR-15, and then finally a coating of chassis paint as the POR-15 isn't UV stable and can degrade overtime, unless over painted.

I'm not sure that's quite accurate - I know POR give that advice if starting from scratch. As I understand it in practice, the metal surface needs to be prepared but this is mostly for new, clean metal - apparently any decent rust converter does the job on a rusty surface (the POR-15 "metal ready" is effectively just a rust converter, same zinc/phosphoric acid stuff as Kurust and many others). You can get UV-stable POR-15 paints, so only one painting required if you use one of those paints. Being in the UK, UV is not over-abundant most of the time and the underside of the car is never exposed to direct sunlight - or if it is, my problem will be getting it back on its wheels, rather than painting the chassis etc
So using a non-UV stable paint is unlikely to be an issue. I would go for a UV-stable one just to be sure - something like the Black Cote over the rust converter.

Will have a look at yours at Lincomb - before you over-coat the Dinitrol with Lincomb quick-set POR-15 is not cheap though, so the Dinitrol route is worth considering

 

[Scott]

The product info for the black cote says:

"Use over POR-15 for the toughest, most permanent protection against rust and corrosion. POR15 BlackCote is non-porous and will not crack, chip, or peel. Has amazing scratch and abrasion resistance, not sensitive to ultra-violet light and may be applied over POR-15 or other Paints.

Blackcote has a beautiful gloss black finish and is perfect for restoring the gloss black frames, chassis and underhood parts of earlier vehicles."

I may be reading it wrong, but I believe this to be a paint to put on top of the POR-15, and not actually the POR-15 paint itself. Hence the two coats. It's up to peoples individual choice whether they use a rust stabiliser/converter first, but I thought as it was your intention from the outset to treat rust that has already started, you'd be using a rust stabiliser as well as the POR-15.

On a different note, I have a friend who painted his chasis with POR-15 and when, at a later date, he decided to weld some additional brackets to the chassis, he found that it took a lot of effort to clean the chassis back to shiny metal to weld to. So it certainly adheres well.

Cheers.

 

[Birder]

Andrew: for 5 years up till 1999 my company Linco plc were the UK aftermarket distrubutors for Dinitrol. Under the trade name Autoline we sold their windscreen adhesives to the UK windscreen replacement market. In the late 90's we supplied the retail packs of all Dinitrol rust preventatives.

Dinitrol waxes won the Practical Classics 'Best Buy' award as the best underbody product. Linco plc supplied 5 products for test

Rust Converters:

RC800 is a rust converter which works like Kurust convert rust into a stable compount so it can be painted. RC800 is brush on, RC900 is Aerosol.

It a waste of time using this product if there is no rust in the first place so if you clear off the rust it does nothing.

RC800 came second with Comma Stop Rust winning the Best Buy in the tests

Waxes:

Dinitrol 3125 is a clear product for used cars and it won hands down due to the fact that it creeps into joints. If you imagine two pieces of metal flat against each other 3125 will creep in the gap 20mm, none of the other waxes tested would do this. In fact it would creep 40mm in our own tests.

However on its own it does not last long

Dinitrol 4941 is a black undercover wax that sticks like S**t to a blanket and stays there

We also supplied 2 other waxes by Dinitrol for new metal

The best by far was RC800 on flaking rust or Comma Stop Rust, then 3125 on all joints where penetration is needed, then 4941

Apply by spray or brush in hot weather, then leave for it to seal itself. We heated the cans before we applied so it went everywhere.

3125 and 4941 used together will reseal itself after a stone chip unce it gets hot.

Fantastic products other than price, i found that brushing areas that needed it rather than spaying everything cut down on cost and still did a good job