Krown Rust Control

First time using this forum, but I had a question about Krown Rust Control.

Where I live there is Krown Rust Control center and I went in and talked to the guy about what Krown was. I got a lot of information but I could really tell the guy was trying to sell me and persuade me to get my 2008 sierra lined with Krown. I just recently got all the rust repaired and fixed and was wondering if anyone on here knows a lot about Krown and if they would recommend it over undercoating or and other rust prevention. I have heard Krown is the best of the best but wanted to know and see if anyone on here knows first hand that it is the way to go.

Thank you, all replies help.

Don’t confuse undercoating with rustproofing.

Undercoating is applied to the underside of a vehicle to deaden vibration and road noise.

Rustproofing is applied to the body cavities of a vehicle to prevent rust

When undercoating is applied, the surfaces must be absolutely clean.

If this isn’t done, the undercoating doesn’t adhere properly to the surfaces creating voids between the undercoating and the vehicle.

These voids accumulate moisture which promotes rust.

And with Krown, you never stop purchasing it.

Solutions such as Rust Check, Krown, or Corrosion Free are applied by professionals every 12 to 18 months at a cost of $100 to $200.

Rustproofing is sprayed into the body cavities with wands thru drilled holes.

Again, the surfaces must be clean for the rustproofing to adhere properly so it doesn’t promote rust.

Undercoating and rustproofing are usually applied when vehicles are new because that’s when everything is pretty much clean.

But automakers advise against doing this because of the reasons above.

And because they feel the rust protection with aluminized and galvanized steel along with the dip process is enough.

And in some cases it voids the corrosion warranty when these processes are done

It’s best to wash and wax the vehicle every six months.



Me thinks on a 13 year old vehicle that already has rust ( not all of it can be seen ) it is a waste of money to have this treatment.


Since this is a 2008 that has already had rust repair… and rust never sleeps, the rust will come back no matter what you do.

There is rust that isn’t apparent that will make itself known in the future. Krown couldn’t hurt, from what I read, but it likely won’t stop the rust that is already happening on the 13 year old truck.


Yes, but it will definitely hurt the OP’s wallet to pay for something that is very unlikely to stop the inevitable march of rust damage on a 13 year old vehicle.


But if $200 a year gets him 3 or 4 more years out of it it might be worth it.

My vote is to forget it for all the reasons stated above.

I spray the undercarriage and body cavities of my vehicles with Fluid Film every fall, just before road salt season. Fluid Film is similar to the Krown product. The cars range from 2000 to 2009. To me, it has slowed the rusting process dramatically. The heavy undercarriage steel is all in good shape. The sheet metal on three of the four vehicles is in good shape. The fourth is a Dodge Grand Caravan that rusts when you bring home table salt from the grocery store.

1 Like

I’m with the others. Even if Krown works (and I will admit that there are lots of people who swear by it), an '08 is probably already rusting, even if you can’t see it yet.


Rustproofing is very useful in my area because of lots of snow, tons of road salt every road mile and relatively warm winter conditions where it vacillates between just below freezing and just above for much of the winter. A formula like krown with a lot of creep is best for us. As others have said, nothing stops rust, the goal is to delay iy. Properly applied it seems to add 3-4 years to the life of a car, say fron 9-10 to 13-14, ell worth it in my book. I have no financial interest in krown or any other rustproofing and have never used krown itself but have used similar products. and even bought the materials and did it myself on a Plymouth Horizon. I remember 3 year old car covered with rust around herein the 50s and 70.

If your rust repair is warrantied, will applying a rust preventative like Krown void the warranty? If it were my vehicle, I would still apply the rust preventative regardless of the warranty, because I think it helps stave off corrosion that much. But it is something you may want to consider.

It seems the service costs $150 for a 4 door pick up truck, annual application is recommended.

There was a regular on this message board that performed a similar treatment once a year and claimed it was very effective, no rust for a decade or more.

Haven’t you ever applied grease to your wheel hubs? Grease and oil are effective in stopping/preventing rust.

It’s not that there is no substance that can stop rust. It’s that it’s incredibly difficult to get that substance on 100% of the rust-prone components in a car. If that Krown stuff misses even a little bit of metal, and it rusts, the rust will then spread underneath the Krown.


The rust will defeat the coating of oil?

The rust will defeat the metal that isn’t coated by the oil. It will then spread on the backside, unless the Krown somehow drips underneath and coats it there.

Kind of like how rust can spread even under paint, because it’s rusting from the inside out.


How is that worse than having no rust protection at all?

When did I say it was worse?

Aren’t you implying that the product is ineffective?

I’m saying the product will not be effective where the product is not present. The same is true for just about any product.

Are you implying the statement you just quoted is untrue?


Personal opinion is that any spray on corrosion prevention treatment is worse than doing nothing as any chip or scrape in the undercoation creates a point to retain moisture and accelerate rust develoment.

Scrape, sand, treat, prime and repaint is the only real solution but it’s actually very effective.
Just look at any Pre-2000 car that’s still on the road…