Links to products used in the video: Rubberized Undercoating:amzn.to/2ZBYo3H POR 15: amzn.to/2DBInkW Stabil Rust Stopper: amzn.to/2XRW86m CRC Corrosion Inhibitor: amzn.to/2ZONbwK RP-342: amzn.to/2XOaTar Amsoil Metal Protector: www.amsoil.com/shop/by-produc... LPS 3: amzn.to/2DD5fjJ NH Oil Undercoating: amzn.to/2GPJoaT Fluid Film: amzn.to/2IZP5o3 Help support the channel by using my Amazon links As an Amazon Associate I earn from qualifying purchases. Here is a link to Krown's lifetime warranty policy: krown.com/en/warranty/ At the bottom of this policy Krown states that any unpainted undercarrage parts of a vehicle involved in an accident must be repainted then, Krown must be reapplied to keep this lifetime warranty. Sounds to me like Krown is fully aware their product does not work on bare metal.

Young Man, I want to give you a heart felt, sincere thank you for your thorough, well worked review of these different products. You saved me time, money and frustration from a hit and miss approach. Thank you.

I can't believe no one from the utility company took it down over all those months 😂 This was an awesome test, with so many products!

My experiences with Krown. BTW we live in St Andrews NB Canada right on the ocean, actually it is a peninsula island surrounded by the ocean.1. My wife's 08 Acura MDX was treated new by the dealer in Ontario. We bought it in 2012 in Nova Scotia, no rust. Continued with the treatment until my daughter totaled it (she is fine) this past August and there was no rust on our X anywhere. The tow truck driver was shocked with how good the condition that our old X was in and could not believe the frame did not crack in half and that my daughter walked away when she crashed into (along) a tree line sideways at 60 MPH until a tree finally brought her to a stop.2. 2006 Civic purchased in 2010 in PEI, treated for the first time then, rear ended by a 17 yr old texting in 2017 no rust anywhere.3. 2013 Civic (replaced the 06) purchased in 2017, started treatment then, no rust anywhere and I crawled under her in Sept, looks brand new.4. Now here it gets impressive. 1985 26ft Coachman RV bought in 2012, 27 years old, never undercoated, got it for a song and did not realize who far along the rust was on the frame and even on the engine block and yes, everywhere else. My wife and I figured we will enjoy the old girl as long as she lasts. We have treated her every year since. You would not recognize her now, black as the Ace of Spades, no rust ANYWHERE. She looks brand spankin new under there and I was just under her changing the oil for the winter last month.I enjoyed your test but I will stick with the Krown.

I bought a new ram 1500 Big Horn hemi. I took it home and spent five days taking it apart to use fluid film to prevent it from rotting out the way I see a lot of ram trucks rusting out. I pulled the fender liners out, I took out the grill, the headlights, the tail lights, I took the rubber off the top of the rear bumper, I took the runningboards and the running board brackets off, all of those things I took off so I could get fluid film under them before the salt got there. I took the access cover off of the tailgate to spray inside, I bought the fluid film attachment for the spray cans it’s a bout 4 feet long hose and I went in the access holes of my ram all the way up to the roof on both sides of the windshield, and the door posts. Two years later, I’m getting ready to do the third application which I am going to do every year. There’s no rust under there.. My last truck was a 2008 GMC Canyon four-door 4 x 4. I bought it new also...I read the owners manual cover to cover and in the owners manual it said, if I undercoat the vehicle, I void the warranty. So I did nothing as far as undercoating on that vehicle. I thought general motors must be very confident in their corrosion coatings protection....Well I ended up losing the brakes twice from rotted brake lines, I lost the fuel lines from rot, the supports for the bed and the back bumper were so thin from rust that during an annual state inspection, the state inspector told me that this metal holding the bumper on it’s not gonna last too many more years. The bumper was bubbling, the chrome had gotten salt under the chrome finish... I had to replace the front brake rotors, I discovered the splash guards for the backs of the front rotors were disintegrated from rust. The frame was completely covered with sheets of rust that would come off with a scraper in sheets. The only thing I ever hauled in that pick up truck was a picnic bench kit, and a washing machine once. It was not at work vehicle. It was what I consider to be an SUV with a bed on it. The corrosion under that vehicle scared me into trading the truck in, it only had 42,000 miles on it, it had never been in an accident... I was very lucky that the body and the finish on the truck still looked like new, so the clearcoat and the General Motors paint job held up very well. That’s why I spent five days rustproofing my ram 1500 with fluid film. Because of what the salt in Pittsburgh Pennsylvania did under that GMC. I did try saving the GMC with POR 15 on parts of the frame. There are heavy warning labels on that about getting it on your skin. I wore long sleeve work clothes and gloves with cuffs on them. I coded my face with Vaseline. But I got some of the poor 15 where the gap on my arms between the gloves and the long sleeve shirt left my skin exposed. I ended up going to two different doctors because of what it did to my skin. That stuff does not come off.. I was diagnosed with folliculitis. And I missed two days of work because of the rash looking damage it did to my skin. It looked exactly like poison ivy or poison oak covered skin. POR 15 is dangerous. Not only is it Difficult to work with, but it did not stick to the frame on my GMC on the upper control arms which I was able to prep with a wire brush and spray with brake cleaner .. you can’t just attach a sprayer and stick that into a door where you can’t see where it’s spraying and cover everything in there with POR 15. If you get it on the glass, how are you going to get it off. It doesn’t travel like. Fluid film does. Fluid film that I sprayed actually traveled up hill. The bed of my new truck was factory spray coated with black undercoating bedliner it looks like. There are holes in the walls of my truck bed for ??That fluid filmI did not spray in the bed, but it got near the drain holes and it actually traveled into the bed and uphill through those accessory tiny holes in the wall of my bed. And it traveled into the bed through the drain holes in the bed. The fluid film spread out in about a 6 inch circle over the first summer. So that stuff does travel into the nooks and crannies where you wanted to go to get there ahead of salt..So when it gets hot, that stuff travels into the areas where salt water make it before salt water gets in there... I read that fluid film is actually good for leather. I coated two pair of my work boots with it and a couple of belts that were suffering from age, they were getting hard and not flexible. My red wing work shoes sucked that fluid film up and he feels soft and supple. My belts softened up also. And they look very good like I had just polished them. Fluid film was running out of my hood and down over the glass on my headlights of my ram 1500 this past summer because of the heat of the sun. It just wiped off. For the last two winters, I coated my chrome bumpers, & my factory chrome mag wheels with fluid film, and I left it on there all winter without touching it. I just put it on the rag, and wiped it on and left it there. It just looked shiny. When I washed my truck after the end of winter, The bumpers and the wheels looked like new.. I put plastic aftermarket fender molding on all four of my wheel arches as well as mudflaps. Before I put the wheel arch covers on, I sprayed the entire painted area that the plastic cover would cover with fluid film and put the plastic wheel arch covers over that thick layer of fluid film. The reason I am so meticulous about the rustproofing is because I am retired now, and this truck cost more than I paid for my first house. In 1977, I bought a brand new Ford Econoline van. I sprayed underneath the trunk and inside the doors with clean motor oil when the truck was new. The truck lasted me 31 years.. The areas I did not spray with oil rusted out, down below the windshield in where the windshield wiper linkage is, and inside the rocker panel on the opposite side of the side door. I only applied that motor oil one time in 1978. The truck only had 67,000 miles on it when I junked it, because the frame and the suspension components just were a little past it.. I wish they had fluid film, or I wish I had known about fluid so when I bought that ford van new. I’d probably still be driving it here in 2019

Just a note! Krown isn't designed to be stagnant. It's thin so that it creeps into crevices - it's designed for deep penetration into an underbody of a vehicle. It isn't designed for this use case, which is likely why you saw the results you did. It also isn't meant to be sprayed with a straw - they include one for precision, but it's meant to be sprayed with a shutz gun (at a Krown shop) or without a straw onto broad areas like this. When you spray it, you'll notice it foams like crazy - it's designed to be thin and creep, spread to fill all the cracks, then dry so the rust inhibitors can do their work. I'm not affiliated with Krown, but I know a lot of the engineers who work there and people who own/work in their shops. They're the most honest and genuine people you'll ever meet. The product works awesomely for what it's designed for, and I've seen it first hand. I'm in snow removal in Ontario, Canada, so I'm out driving as they're salting in the worst sloppy, wet conditions. Krown does work on bare metal. I used it on my wheel hubs, brand new unpainted steel, for 2 months in salt-spray and slush - not a spec of rust on the hubs coated with Krown - the one hub that I missed was completely coated in rust.

Great test! I did something similar when choosing my spouse.

The Krown and NHOU are made to saturate the areas inside doors , Rocker panels, quarter panels. You can’t see these areas and that’s where rust will start. By the time you notice rust in these areas it could possible too late and further work will have to be done. If you have to apply it every year it’s worth it. As far as ares you can see like undercarriage and frame you can see these areas on a daily. Wash down these areas with cleaner neutralizer then spray the product of your choice.

Excellent test method and analysis. Thank you for educating us to choose the best product. I will go with the CRC Rust Inhibitor.

this is invaluable, doing God's work my dude

I have been having great luck with Krown. I started using it with a vehicle that was already 4 years old before first application, and subjected to very harsh NY state winters (read SALT!).All I previously have done was a Springtime wheels off cleaning, and paint touch up of mainly suspension components. I started having Krown done 3 years ago. Just the undercarriage. I checked how well it lasted, and protected a year later on a friends hoist. It was 80% still on everything, except areas that are constantly blasted with water, salt, and sand which is used on roads around here. I have been having it re-applied every year since. I pre-clean with purple power full strength, and pressure wash the undercarriage before having Krown re-applied. I don't have to do the cleaning, I'm just OCD, and like to start fresh each year. For the $50 they charge to do just the undercarriage, and the protection I get, I don't see how I can beat the performance/price. Actually I just had it done yesterday. My 7 year old Toyota Rav 4 still has a rust free undercarriage. If I had a vehicle lift, I would do my own treatment, but I would probably still use Krown. Krown also has a salt eliminator that I spray on after winter to neutralize salt deposits which seams to work well too.

Hi, first of all thanks for your time and effort. I however have a story about POR 15. I have a old 4x4 camper van that I converted to run on propane, I purchased 2 old propane tanks, one was 25 gal and the side tank was 17 gal. I sandblasted both tanks used Metal Clean & Metal Ready then applied two coats POR 15. It has been 18 years and you can use soap and water to wash the tanks and they both look like they were just done accept for all the little stone dents on the rear tank, nothing went through the coating, just small dents. So my point is this product is amazing if you do all the prep. Yes all the prep take time, now divide that time by how many years you do not have to do anything again. My idea on fixing things is, fix it right once if you can and never have to do it again.

My understanding is that POR 15 is meant to be applied directly to rust, with some minor prep first. The rough texture of the rust helps the POR 15 grip and stay applied

That explains why the Amsoil HD metal protector has held up very well for the last 3 years of Pa winters. Thanks for your hard work!

Great video. Service manager at a local repair shop in S. E. Pennsylvania, and we keep gallons of fluid film on the shelf and a gun to spray the frames. Tremendous product. I recommend it because it works!

I was all over the place trying to see what works best for my brand new truck. got crazy tar spray quotes from dealership and this video was the most helpful video ever. now i can just purchase a few sprays, spend a day and save tons of cash. this was an amazing video. thanks so much for sharing this.

I used CRC on my Gladiator. Stuff was supper easy to apply. Looks great. Dry. Doesn’t drip. Should do the trick

Any chance of doing a test with a part that is already slightly rusted? Lots of these products claim to stop rust that's already started.

I have used the same Krown dealer for the last 30+ years on 7 new vehicles. Not one ever shown any rust and the city uses a lot of salt on the roads during winter and spring.

A slow seep from the rear main seal has always done the trick for my jeep. Those OEM cork seals seeped just enough to never actually get low on oil between changes, and it never left a drip on the pavement, but it coated the undercarriage quite nicely up front. A brush dipped in used motor oil will make quick work of any dry spots during oil changes.

Keep this test going, I want to see those pieces in 2, 5, and 10 years!

Awesome comparo man. I’ve used Fluid Film on my Tacoma for ~6 years.... video is spot on in that its great in non-direct water spray areas- inside frame rails, crevices etc- but washes away quickly from wheel wells, front-facing suspension. The crevices are where most salt/moisture hides though, so is sufficient in my moderate salt belt area (coastal RI). Perhaps adding CRC to exposed areas would assist.

Like to have seen "Wool Wax" included in the test, it's similar to Fluid Film, but thicker, they both are lanolin based. I would think Fluid film for an initial coating for the thin consistency and small gap filling, and Wool Wax for subsequent touch ups for durability.

Vermont winters are rough like all of the rust belt. Like many of us older guys I've been fighting rust for 50+ years. I've used many products. I've found there is NO one product solution for a vehicle. I love POR15 even with all the prep. Prep is the key. Also, it is a rust converter so it doesn't work so well on clean metal. The creep factor needed for crevasses just isn't there because of the prep needed and exposure to surfaces you don't want POR15 to touch. Fluid Film washes off wheel wells and etc. Not the best for that application I would suggest. For those of us who take pride in our beloved vehicles and/or can not afford to replace our vehicles as often as we would like, I believe time is well spent researching and then applying different products to the various parts of the vehicle. Example, my 2015 Silverado chrome rear bumper rusted on the inside. I removed the bumper, did all the prep and treated it with POR15. "Try it, you'll like it." My 1999 Silverado chrome bumper still looks new. Obviously this will not work inside your doors, boxed frames and etc. The creep factor of Fluid Film and other products is essential. In 1975 I bought a brand new Chevy truck for $3,700. My 2015 Silverado was about $80,000. Vert different trucks but still... You know what I'm saying! Put time into your investment and give it a hug now and then. Thanks for the video! Awesome! We need all the help we can get with this never ending battle.

Rust Bullet - I’ve used it for years and swear by it. It requires NO prep and doesn’t fade under UV. It goes on thick, and is almost impossible to scratch off.

CRC did amazing, I might switch from film to that if I can find it cheap by the gallon. Time to cure is not a problem with multiple vehicles.

I've used the Cosmoline RP-342 on all 3 of my work vehicles. All are prestine and rust-free going on year #4. Coatings stays intact on wheel wells too. Great video! Thanks for the comprehensive review.

@Repair Geek - thanks for putting together such a thorough review. Off the bat, I have no connection with any of these brand manufacturers, I'm just a truck owner who lives in the snow belt. My 2016 RAM, which came used to the States from Alberta, has been sprayed with Krown since day 1 before it ever saw snow. What I can say is that now, 5 years on, the truck literally has no rust anywhere on it except the exhaust pipe - which Krown doesn't warranty and is very transparent about that up front. Krown does not make any claim of efficacy on bare metal. All I know is that when I take my truck to the stealership for warranty repairs, the techs always tell the service manager they can't believe the truck has no rust on it and want to know what that oily coating is on the undercarriage. I think there are many good products on the market. I like Fluid Film too. In the snow belt, any coating is better than no coating. I get it sprayed each year and have had nothing but success with it. That said, are there better products? Probably so and I don't discount any good work you did in this video. Just sharing my personal experience with it. Thanks again!

Nice!! My opinion is stay away from "hard" coatings since eventually they separate away and trap moisture under them. Annual applications of most any product designed for vehicle rust prevention probably will work well. I was surprised at the Krown results!!?? I like the LPS 3 the best from your results, it seems to hold a durable "waxy" type of coating that in my opinion would provide for a long lasting coating and ultimately long lasting protection. I think it's important to consider plastic and rubber reactions to the coatings as well as moisture displacement and "creeping" characteristics to penetrate seams and the like. Great comparisons!! Thanks.

Thank you for doing this, 10 years of Fluid Film in PA 3 trucks, no rust.

Great comparison! Thank you. I use CRC for undercarriage and frame and Fluid Film for inside the panels.

I have to sign in just to give it a like. You save people time and can choose product. This is a great thorough content. Thank you brother

Krown is one of my favourite products, for inner panel protection because it has an excellent creeping agent rockers cab, corners any sheet metal you need to get into to spray it is best because it will get up and move around, using a thick agent like fluid film is best for frames and water washed areas I use both products with great confidence in conjunction

Great test overall and I think you did a good job thoroughly testing all the products, except for por15. POR15 does require several prep steps, which you mentioned, and which you didn't follow at all! You must clean & degrease it, Then you really should use their metal ready stuff on it, ESPECIALLY if its BARE UNRUSTED METAL! Then apply 2 coats of the por15 coating. Also, por15 adheres best to RUSTED metal (with loose stuff knocked off). You should've left that piece rusty, and then properly prepped it per por15s instructions, before coating it. Because of that, I believe you didn't give the por15 a fair chance. It should not have come off from pressure washing!

I want to see all of these mixed together. It would either make a dangerous gas cloud or the most impervious coating known to man.

I live in upstate NY winter is about the same as you mentioned. others have said they appreciate this research. I do as well. You're so right in other videos that vehicles rust out before the engine stops. that's why these coatings are so important. your tests are really helpful. thank you!!!

This is about the best informational video I've watched on KZfaq - Good work, Repair Geek, and Thank You!

Thanks for taking the time to do the extended review.. Lots of good information... I think I am going to spray (On an older vehicle with rust already), Phosphoric Acid to convert the rust to Ferrick Phosphate (black color FePO4) which protects the undercarriage against more rust, and then, I think I am going to apply a home made rust preventative, under the vehicle, and something inside of the doors, door jams, etc.. Might be two different home made products.. Inside of the doors, jams, etc,, something fluid that will coat and run into crevaces, etc.. I am thinking Antifreeze.. Rust and Corrosion prevention and Lubrication, I think non-conductive, but, will wash off under the vehicle.. I will have to see if something will mix with it, if I use it under the vehicle, but, something that won't come off so easily under the vehicle.. Thinking maybe some Chainsaw bar oil, or along those lines.. I hate to work on something after a coating like that, but, heck.. What's worse.. Tossing a vehicle that is perfectly mechanically sound due to rust, or, getting a little dirtyer when working on it.. I have a 97GMC Z71, I really, really like, but, rust has me getting rid of her.. Perfectly mechanically sound, but, the rust is pretty bad.. Grrr... I live in North Carolina, so, not getting salted every day, but, it doesn't take a daily dose of it.. Just run the roads after a salt application and the road is wet and that shit will get Everywhere... Who knows.. If the Phosphoric Acid does like it should, I might even do some repairs and keep the truck...

This is an excellent test, verging on Project Farm level. My strong suggestion is to do the same test, only with all the pieces rusted, and test the various rust remover/encapsulators first, then the above. Thats going to be the normal way/conditions wherein the products will be used.

Simply outstanding. I too live in NE Ohio, and keeping a car together here is not easy. This will help those of us who like to drive team after the payments are done. Thanks!

Hi this is awesome. My go to is boiled linseed oil because it is cheap and dries to a semi permeable self healing coat that does not trap moisture. You can brush it on or thin it with mineral spirits and spay it out of an windex type bottle. Plus you don’t have to prep. Once it dries it trays on fo years like paint

Nice coating test, always cool to see the test winner. Glad you tested Krown, I am more informed. The Por15 is not UV stable, most likely developed a small fracture and seperated when pressure washed. Maybe next time you can paint the other half of test piece with an additional top coat paint as manufacturer recommends. Keep it up! 👍

Excellent video. Thank you for spending time doing this. I was almost ready to get Krown coating too.

There is a great way to use rubberized undercoating in mix with wax type fluid film. Prep surface, spray with rubberized undercoat, and then just before its dry spray it over with waxy fluid film. the fluid film seeps in to the undercoating and does not allow to go super dry and crack. the rubberized undercoat acts as a sort of sponge to hold the wax in and does not allow it to fully wash off. works like a charm.

I sprayed cosmoline on my truck frame over 2 years ago. It’s still there and not showing any signs of coming off any time soon. I think it’s the best product

Impressive.. this just might be the most informative, useful video I've seen on KZfaq. Bravo!

After being around cars for a majority of my life, either as a mechanic/technician, sales or Frame and Body Technician and seeing all of these products that have come and gone, and those that need to go, there are a few things to take into consideration when or if you decide to apply something like this to the vehicle. The factory releases their vehicles with a rust inhibitor already. That being said, just like the paint on the outside, the undercarriage needs to be maintenanced from time to time. But one of the reasons these don't work is because of improper prep. Many people simply spray or apply these chemicals to a dirty car/frame. Others think that simply pressure washing the vehicle for a few minutes will do the trick. Often times a person will use some sort of degreaser while they pressure wash it. And then there are professionals that will take the time to pressure wash, degrease and then prep the undercarriage and then USE THE SAME PRODUCT THAT THE FACTORY USES. Trying to add a new product on top of another one without actually removing the old stuff is not the best way to go. Yes, your method was bare metal, which is a test base, and shows those specific results. As I said before, there is already some sort of rust proofing applied to vehicles. The other issue is with the ones that stay tacky and allow debris to stick to it can/will cause certain areas to cake debris, which tends to attract and hold moisture, sand, salt in cracks and crevices, which as we know attributes to corrosion. The other MAJOR MISTAKE that a TON of people, both DIY and some "professionals" make is that they CLOG holes that the Manufacturer puts in the various parts, which then creates a pocket and the inside of the rails, body panels, etc. and corrosion starts to destroy the vehicle from the inside out, and no one can see or treat it until it is too late. Again, the best way to take care of this issue is to wash your vehicle, from top to bottom on a WEEKLY BASIS, even and especially during the winder/salty months. Then when it is warmer, get under/put the car on a lift, and inspect everything. If you see corrosion starting to form, address that one spot. If there are some bolts heads or threads/nuts that are corroding more than normal, address those by hitting them with a wire brush and maybe some black paint. But if there is an area of the body or frame rails etc that are starting to have some surface rust or scale, then address the issue and then get the SAME TYPE of undercoating that the Factory uses or recommends. You can get some "undercoating in a can" and reapply it to those problem areas. Make sure that you mask off anything you don't want to get spray on, like the exhaust, bumper, fender lip, roll pan etc. because once it dries, it is not nice to remove. Plus it doesn't smell good when it burns off of the exhaust. Please, don't simply spray something on the bottom of your car and think it will stop rust/corrosion from happening. Also, make sure it is compatible with the factory applied product as well as the metals and alloys that are being used by the manufacturer. I have also seen products used that actually caused corrosion on alloys.

I did a similar test myself and the Cosmoline RP-342 beat the other twenty-or-so products I tried quite handily, even with just one coat. If you live in an area with snow and road salt you're doing yourself a disservice if you leave your vehicle untreated, shaving years off its life. It will literally die from rust while still mechanically sound. In my area it's quite common to see three-year-old pickup trucks with gaping rust holes along the lower doors, rocker panels and wheel arches. Pro-tip: Don't forget the cavities; your car may look good on a perfunctory inspection all the while it's rusting from the inside out.

For me on my 2015 WRX (as of this writing almost 62K miles) I had done the NH undercoat a few years back. I live in New York and drive the car daily. Had gone to a shop and I was under the car while the dude was spraying the undercarriage. I had cleaned the undercarriage before going. Was sprayed in all accessible nooks and crannies that I could see. It attracted dirt and got on you when working on car. My garage thought I had blown something and oil sprayed everywhere lol. I was told to do the undercoat yearly but never did it after that. As of this writing I've used CRC rubberized undercoat a few times afterwards. I did not remove the NH undercoat and it seems to be doing a good job. Just the other day I took a screwdriver and stabbed/hit parts of the undercarriage and didn't seem like I had a rust issue. I'm sure that the car is rusting elsewhere that it was not treated but knock on wood so far so good... I know my muffler system will not rust since I've replaced J-Pipe and catback along with various other components that were rusty when removed. One thing to note is the rubberized undercoat made it SUPER difficult to get the front and rear diff drain plugs off. I got the rear one off much easier after using heat gun a bit and 1/2 cheater ratchet. For the front used impact gun. So yeah the undercoat while it protects well it also definitely makes it much messier and more difficult to work on the car. Hoping to keep the car for many more miles :)

I never had a problem with Rust Check spray! You have to do it every year like Krown which is very similar! It is worth it! Never had any rust form on any parts of my Chevrolet! Rust Check will also re-spray an area that was repaired from a collision free of charge too!

The pressure washer is a great idea, good way to simulate splashing and spray while driving, well done I’ll stick with my crc marine, cheapest and seems to hold up as well as any premium products.

I live in Detroit and go to Windsor Ontario to get the car sprayed with fluid film. It’s $100 at Canadian tire.

Very helpful video. Just bought a new truck from a dealer ship and they tried to sell me an undercoating. I am an engineer by trade and asked some material and application questions and the sales men could not answer them. He is going to find out from the service department what kind of undercoating and rust prevention they are selling. After researching and making inquires of my own it may not matter what it is. Input cost of these products is drastically cheaper then the one being offered by the dealership with the same if not better results yielded. Thanks for taking the time to put this video together, for using good scientific practices in your experiment, and for creating an effective method for communicating the results.

Thanks for taking the time and expense to do this test. My local Fluid Film shop, which I have been pleased with, just switched to NH Oil. I was thinking about trying it, but I'll find a new shop instead.

Thanks for your video results with clean bare metals. But there's majority of car owners actually applies these rust prevention undercoating after a few weeks - a year after their vehicles purchase. The product that is going to have the best results in those situations would probably be Fluid Film, Krown, and other oil penetrating undercoating products. All others are not good for it once dust, dirt, moisture, and multiple surface paint chips or minor surface rust sets in.

Now THAT's what I call a well done comparison review.

What I've noticed,from spraying,and use in other areas,as a lube,anything that has a paraffin base OR WAX base long term parts protector or rust preventative usually will out perform other products.In heavy industry,before we package parts in a warehouse,we spray with a parrifin base long term parts protector.I tried it on my vehicles,its wax base,and it hangs tougher than any other product.Any wax base will last much longer and will "creep" in the hot summer temps.I also bought a new VW in the early 90's and the germans undercoat using wax base also,that told me something right there,and that golf did not rust for years.Just an FYI based on my experience.GREAT video!!I use spray on all my hobby farm equip,it works!!

I have been waiting for a rust proofing shoot out video. Awesome. Thanks.

Great reviews. Was very surprised by the performance or lack of by krown. I've been using fluid film for a few years now with excellent results. Some of the other products look interesting but I think I'll stick with what I know works. Fluid film is an amazing product. Just wish it didn't wash off so easily.

I live in the NE Pennsylvania Rust Belt .2 years ago I treated a 2019 Nissan Frontier with CRC Heavy Duty Corrosion Inhibitor in some areas and WoolWax& Fluid Film on 90% of the underside . I was under the truck today to recoat with B'laster Surface Shield . The truck looks outstanding underneath . The was a small amount of rust on the spare tire steel wheel on the welds and there was rust on the frame welds where it was never treated . The rest of the truck had zero rust . All the Bolts and brake/fuel lines look new . I retreated all ares today with the B'laster . Well worth the effort just be prepared that these products do attract road dirt especially on the passenger side . The CRC "only "areas look great and it seemed to attract far less dirt than fluid film . CRC will chip so keep that in mind .

I live in Canada. Krown is heavily marketed as the best. I used it and still some rust came but it was always on used vehicleS. They claim it must be a new vehicle with zero rust for the claims to stop rust from starting and spreading etc. They offer free body repairs but the fine print gives them a loophole. I asked the technicians who apply it professionally and they all say once rust starts it cannot be stopped. It can only be slowed down. I always had my suspicions of the claims that Krown, rust control makes as being the best. Thank you for this video it confirmed my observations of seeing a dry and rust formed under body of my vehicle in the middle of the winter. The one good thing about Krown, is because it is thin it will get in all the tight and hard to reach areas of your vehicle for protection. But the areas that are directly exposed to the salt and brine solutions they use on the roads it cannot stop the rust. THIS IS AN EXCELLENT VIDEO SHOWING THE PROS AND CONS OF DIFFERENT PROTECTANTS. THANK YOU. AAA+ - Side note. Use Krown in the spring or summer after you have desalted your car. Apply Krown, then because rust becomes more active in warm weather.

Well done video - Amsoil HD is available as low as about $10 for amsoil members - and the can is much larger than most

Thank You Repair Geek ... for all the time, money & effort put forth here .... I redo Fluid Film on my semi & pick-up every fall ..... really fights the battle against road salt & brine ..... I wish " we " would go back to sanding ONLY ....... Let the people who must speed in the winter crash ... the Darwinian Effect will prevail ..............................

Fyi, Your using POR15 incorrectly. It stands for "paint over rust". Paint it over rust. It chemically bonds to the metal. If the metal is clean it won't adhere. It's also affected by uv and needs to be top coated.

Krown is a good product. It has decades of positive results to back it up. The spray can's you can buy are going to be thinner because it is in Aerosol form. I would imagine the product is a lot thicker when applied at an actual shop. If you are doing it at home I would apply it once a month to ensure it stays coated.

Thanks for all your work Cosmoline all the way

Thanks for putting the time in...great study and results. I've been using Fluid Film for a while and your results make me feel better about that.

I had an appointment booked in a few days to get a $300 Krown coating put on and I cancelled it because of your research, thanks man you saved me money and my car

Excellent, going with with the CRC wax-film. Heard great things about these and the video confirmed it.

Best rust proofing that I have found is to live in the South....

First things first, excellent video and I really appreciate the time and effort you t to do this took to do this test. As a Canadian who's vehicle sees salt yearly, Krown used to be decent before when they had a thicker coating, over the years I've noticed they reformulated it to be thinner and more watered down, IMO it's not effective at all. Not mention the technicians only spray where you can see and drill a bunch of holes in your vehicle frame. I wouldn't recommend it. From your test's I think I'm going with LPS3 or Fluidfilm. Subbed! Cheers bud!

Repair Geek One thing to note about NH Oil is the difference between the black & the clear. The black is tinted because it has graphite mixed in. Other than that awesome comparison and video. 👍

I used CRC400 on my new 98 Ranger XLT supercab and 22 years later the rockers, tailgate, drivers door have no rust whatsoever. The passenger door has a fist size hole at bottom because I missed that area. Even the aluminum driveshaft looks new and frame is solid. No bolts have been hard to remove for suspension maintenance either. It has 230,000 miles of daily driving in Michigan weather and salt there are no Rangers from that year that aren't piles of rust so I have to say that any type like fluid film or CRC 300, 350, or 400 like I used will save your investment. Thanks for the video.

What the heck took me so long to find your channel? Good stuff! Subbed!

I’ve been using Krown for years and my car looks in very good condition. Now comparing it to the spray can of Krown, is there a difference between the spray can and the professional stuff they use at the Krown shops?

Krown is good for inside of doors and body panels. It stays in liquid form so it can run into places that didn't get sprayed. I use a hydride method of Krown inside doors and panels and Fluid film everywhere else. I reapply every season and use had good results.

Krown is quite bad. I did my own little comparison between Fluidfilm, Rust Check and Krown. 3 pieces of clean bare metal from the same bar. I sprayed them once a day with a brine solution made with de icing salt and water. After 3 days the piece treated with Krown started to rust and was entirely rusted after a week. Rust Check held the rust off better and took a couple of weeks to show rust. Fluid fill protected the metal for 3 weeks before showing some rust. I'll never go back to a Krown shop with my car.

amazing video and dedication man! thank you for this! this is proper testing

Thank you for doing this test. This is exactly what I wanted to do this fall and you did it already. Thank you!

This was not an Idea and an instant video to make and I commend you for your diligence and patience in it's making. It is unbiased and shows the stamina that Fluid Film has. While others use solvents FF does not. In Canada it can be used in food manufacturing plants, it will not harm the environment. It does not need to drip off your vehicle to work that is just an excuse others use to justify their thin weight product and it's ability to cling to the surface.

CRC also won another shoot out . Was CRC Heavy Duty Marine Corrosion Protectant, probably same stuff.. Seems it is the best compromise for protection , cost , ease of use , not attracting dirt or being sticky forever...great video

I love smell of fluid film....great video for such a young guy...like a Scientist!

Applying POR 15 to your control sample will give you superior results, because it works with surface rust, and will not bond as well to clean metal as it does to prepared surface rust.

I use NH oil (they are local to my area) I spray my truck twice a year once in the early summer once in the early fall before the snow comes though. I notice far better results in terms of the coating spreading and adhering itself to the frame when it’s applied at higher temps. One part of your testing that NH oil and other companies use to help keep the product sealed in is its capacity to get dust and dirt to stick to the coating allowing for the interior of the coating to stay protected to the frame. I notice in about 6 months I’m due for a touch up application

Thank you for the testing. I’ve use Ziebart on the last pickup. Your at the mercy of the quality of the installer and also the condition of the vehicle when first coated. I’ve used fluid film on a work van in some test area. So far so good. I really do like the black version of the RP-342 and the clear version on surfaces I don’t want to be blacked out. Truthfully, I think something went wrong with the test. I believe the surface needs to be primed with POR metal prep. I believe it helps with adhesion. Here is where I would use the POR15. I’d use on clean rust free metal that needs a show car finish. For example, I’d use it on the differential housing, frame, and metal brackets that are visible on a pickup that sits very high and I want to make /Keep it looking like new or better. I’d also use on surfaces that might see quite of bit of walking or dragging cargo over if I couldn’t use LineX. I really believe for most folks, if you don’t mind a waxy coating and time is of the essence on application and you plan on light touch ups every year….. I believe the WoolWax and Fluid Film to be great effective options. Now, I have a 2007 F-150 that I purchased this summer from a single owner that kept it parked most of its life. It spent its entire life in south Texas and smelt new when I opened the door, it has 68,000 miles on it. Anyway, I live near Cleveland and have garages it until next spring. This winter, if I can find time, I’m going to put it up on a lift, pull the tires, all the skid plates, the wheel well liners, the interior door panels, floor plates, head lights, tail lights, spare tire and and all of the access plugs and panels on the quarter panels. Basically any place that salt water can reach. I’m going to use: (1) POR15 with primer on the suspension parts like the front brackets and parts of the brake rotors etc that I can coat when I install new rotors. These all have some light chipping and very light surface rust. I want to clean them back up. I’ll order powder coated calipers (Note I’ve used the power stop powder coated calipers many times over the years. They don’t rust unless damage to the top coat occurs. The rotors need a new coat of paint every single year and of course will rust where the pads rub). (2) RP-342 heavy duty “clear” on all the surfaces that I can hit and insure a solid coating. I’ll put two coats on it. Clear will allow any future buyer to see I’ve just sprayed a protective coating over the factory paint or primer. (3) after the POR15 is set up, And I’ve gotten two coats of the TP-342. I’ll spray everything else that needs protection with either Fluid Film or Wool Was. For example inside the doors, inside the quarter panels, frame, and hard to reach areas that a wet oily wax Can reach and penetrate. I’ve found the 360 sprayer tip needs a half dozen passes inside a long Barron cavity to fully cover the steel. The great thing about wool wax or fluid film is they kind of act like WD-40 and literally penetrate steel surface areas that are dirty or tightly pushed together. For example, where pinch welds come together and you can get behind or spray directly on the seam. The lanolin oils will literally work their way deeply into the seams and pores of metals. I again the route I’m going is based on cosmetic considerations. When I’m Done it will look a bit nicer and show far less dust etc. But it absolutely will take me 3 times longer than just coating everything with Fluid Film or WoolWax.

Living in Toronto, we share pretty much the same climate. Just wanted to thank you for a very well done experiment and presentation. I was leaning toward RP 342, but if the CRC performs as well and is cheaper -- perhaps that is the way to go.

Thanks for sharing! We need to know this stuff, here in NEOhio!

Cosmoline was once used to protect cars coming over from Japan. It was removed with a mixture of hot water, kerosene and soap. Very informative video!👍

As a long-time scientist in the coatings industry, I can say that you conducted a very objective experimental comparison! Other variables you can consider for (any) future experiments involve coating over partially rusted substrate and perhaps over a factory frame/under-body coating. There are so many corrosion inhibitors on the market these days. I (also residing in NE Ohio) have had our cars treated with Corrosion Free at a local applicator the past few years. This Canadian based company "warrants" the product if re-applied very 18 months. They do sell the bulk material as well as an aerosol version on their website.One of the DIY products on the market that I would be interested in is Boshield T-9, ,supposedly developed by Boeing. This is available in aerosol form via Amazon. Keep up the great work!

Thanks - i found that very informative. In my case I would be curious in a test of spraying these over metal that was rusted already. In my case I have a classic car with some rust, I would like to choose a coating which will provide protection from it getting worse over out wet and salty winters. Additionally, my long term plans are to cut out the rust and weld in new metal. I think I will be choosing an "oily" liquid style coating. I expect that the fluid oily stuff will keep the rust from spreading but also be easy to remove when comes time to repair. In contrast I think por15, rubber undercoating, and the other products which "dry" would seal any rust and moisture under the coating where it would still continue to corrode and react (when sprayed over already rusty metal).

Great video! I’ll definitely go for CRC

Suggestion for another real world test, one that is more inline with the intention of these products. Already rusted painted metals, like what is found under cars. Even cars brand new on the lot will have some rusted metals, not everything is painted. So, what you do is take these same pieces of metal you used. Clean them thoroughly, then mask off half and paint it properly, metal etch, primer, and single stage like what is found underneath. Then unmask, and let them get a light coat of rust on them. Now treat them with the products without any cleaning up other than a degreaser and spray them with a salt solution before setting them outside for the winter. Those that come back without additional rusting would be the real winners to this test. I have a real world test going on right now under my F350 with Fluid Film. Bought it used and there are some rusted areas I tend to properly treat next year with a permanent rust conversion and repaint, but for now I have them all deflaked and fluid filmed. Will see if any rust grows or if they remain the way the are.

Thank you so much for this demonstration. I used to use fluid film, but I have switched to Cosmoline RP 342. Hopefully I wont have to apply the cosmoline every year, unlike fluid film. Thanks once again for taking the time to post such an informative video.

Thank you for this test. As the results we're suprising and now I can draw a conclusion of what I'd want to use. 👍

Thanks for this video! I've been looking for a video just like this! Sounds like I'll be going with CRC!

Cosmoline products sound like the best choice. 1. It's mostly clear. You can actually see if the product is working 2. It cures to a solid/waxy finish. You don't have this oily mess with a ton of dirt and grime clinging to it 3. It does't come off easily. You could run it through a touchless car wash during the winters and not worry about the product washing off 4. IT WORKS!

I worked in body shops for 47 years. The word on the street for inside rust proofing is Seal-Out. Bought a used Gran Prix with 50k on it. Used it on the inside of the doors and laid a bead on the pinch weld. Cleaned it up for sale and no rust after five years and 160k.

Need to do it with the metal already rusted. That would show how well one of them works to slow / stop the rust from getting worst.

Best product that i've found is Rust Check. Apply once per year and you're good to go.

The overall design of the test was really good. All the pieces got the same treatment and were as close as possible to identical at the start. But you dropped the ball with the POR-15. You can't ignore the manufacturers directions and then blame the product when it fails. POR-15 is very clear about the prep necessary for proper adhesion. It needs preparation just like any other paint because it is a paint, that's what the "P" stands for, "Paint Over/On Rust". POR-15 is also not UV stable- being left out in the sun for five months may have contributed to its lackluster performance. Yes, it's a lot of extra work. But the idea behind a test like this is to see which coatings do the job, not which are easiest to apply. POR-15 might have blown everything else away if it had been applied properly, we'll never know.