Real World Undercoating Test: Fluid Film, NH Oil, Krown and More...

[@RepairGeek]

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.

[@XYZ-sq7ki]

Do people ever mix inhibitors… say use CRC in crevices and FF everywhere else? I just bought my first car (brand new)

[@jonpatrick66]

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.

[@jeffwilliams9086]

I second that comment…I have watched a lot of similar videos but believe he has done the best on this subject of undercoatings!

[@nelsyoung833]

​@@jeffwilliams9086 You are correct.

[@oflchen]

This, my friends, is called SCIENCE! He's got a control and everything. Very well done.

[@user-po7iv4ni3o]

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!

[@harrylime5147]

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

[@actioncircus1]

The holes they put in the frames of vehicles provide a few purposes: Water / road salt drainout, engineered crumple points in a collision, the holes can be markers for when the car is assembled, and the distances between holes are measured by the manufacture and are used for re-aligning the frame in a collision (I'm a collision repair technician).

[@missingremote4388]

I have just sprayed StaBil rust stopper undercoating on my 1995 GMC. It's never been Zebarted not had other protection applied before. So all the frame and body mounts had surface rust. Never garaged so it was an orange rusty mess. I made a KZbin video halfway thru the process. Thanks

[@missingremote4388]

@walt charamba I named the video, StaBil rust stopper works on suburban kzbin.info/www/bejne/rIWthJ-brMSksMk

[@missingremote4388]

@walt charamba thanks. I'll think about getting a permanent undercoating. Wishing I could do a frame off restoration just to preserve the frame: ( and prevent por15 overspray ) lol

[@mark2073]

I bought a can of POR15 a couple years ago and didn't use it. After seeing KZbin reviews that aren't favourable I managed to sell it a couple months ago for $5 more than I bought it for!

[@Mattjki]

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

[@chriswalters8556]

Matt Kind I love you 😂

[@donaldcrossley5937]

And how did that work out?

[@upinvermont3064]

Always wondered why she made me stand in front of that telephone pole overnight.

[@denduq92]

Matt Kind you sprayed them all down and kept the one that handled it best?

[@finalthought3888]

😂 nice

[@robertjohnson4401]

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

[@sako4me]

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!

[@MindbodyMedic]

this is invaluable, doing God's work my dude

[@rubbersole79]

Or, as Norm MacDonald said to Ricky Gervais....."Doing nothing's work" - LOL

[@ruebanh9493]

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!

[@Rammykazemi]

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.

[@pinoyboyfernandez4396]

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

[@Walkop]

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.

[@james1939-s1c]

If it can't protect a clean piece of metal hanging from a pole, its not going to protect my frame going down the road.

[@parkerbohnn]

Works extremely well for bearings in computer fans even better than slick 50 or duralube oil.

[@Walkop]

James Ryan even in this case, it did protect it. There's a film of rust in some areas. If that's your underbody, you're still safe for decades. The point: this isn't a traditional application of Krown, and the product isn't heated like it is in a shop. You're going to get different results. Besides that, Krown isn't designed for max protection on bare metal. It's designed for max *penetration*, and good protection. If you spray thicker undercoating products, they won't spread the same way. Especially in areas that are already rusty. Meaning you'll still get breakdown of parts in the really rusty areas other products couldn't penetrate to. They have another product they don't sell, as well, T-45-its thicker, for heavier protection. I don't know when they spec that for use in the shop. Again, I don't work for Krown...nor am I sponsored, paid or anything similar to promote them in any way, shape, or form. I just know my real-world experiences are totally different from this test. I can't explain why, but I know it works.

[@Al-jv2xb]

Creeps alright there is more product falling off your car onto your driveway rather than stays on the vehicle. And FYI Fluid Film does the same thing. It's just Krown's excuse for dropping off.

[@Walkop]

Al Al that's also incorrect. That is a training issue if you're getting tons of drippage. Krown only needs less than litre of product to protect your whole vehicle. Most shops overspray to make sure everything is covered; but too much can cause excess dripping and attract dirt until all the carrier oil evaporates. Dirt=moisture, so you don't want overspray. They've also changed the formulation in the shops recently to make Krown significantly thicker, but it is HEATED in the shops for application. This allows it to become very thin when applied and allow all the faster initial creeping to occur, but once it dries it still creeps while being less likely to drip. Fluid film does the same thing, yeah, but it's simple physics. If one product drips more, it's thinner/lower viscosity/WILL CREEP MORE. It's a balance. Krown will definitely creep more if it drips more. The new formulation will definitely affect that, and bring that balance into a better position than any standard Fluid Film application could, but it's still a choice, an intended trade off whichever way you go.

[@ommaigod]

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

[@chriss3269]

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.

[@RepairGeek]

I don't doubt your results at all. If you can make any concrete conclusion from my testing it's that any treatment is better than no treatment. Thanks for watching.

[@toddrobinson2547]

Hello fellow Canadian! I think the key to success with Krown is the professionalism of the franchise and likely your own efforts to clean and maintain the cars. Give your Krown franchise owner a big hug. Here in Barrie, Ontario Canada my experience with the local Krown franchise was not so good and the results cost me as their warranty is worded so that you have no choice but to pursue legal action to make a claim. It’s a crap shoot with Krown. I DIY’d my other cars with Rust Check and Fluid Film with much better results. The liquid brine they spray on the roads here in Ontario is considerably worse than regular road salt.

[@macfady2181]

I'm from the Maritimes as well. I typically get Krown the first year or two when I get a vehicle, then do it myself using their panel holes, etc. I get tired of paying $130-150 every year to have Krown do it, times X number of vehicles, considering how much product you can buy for that price.

[@Vertignasse82]

​@@macfady2181I just bought a brand new Outlander PHEV here in Quebec. Do you think I should treat it with Krown? I was thinking just the undercarriage, because of potentially sensitive electronics in the doors, etc.

[@SweetSpringFarmer1222]

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

[@Kactapuss]

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

[@joq702]

Yes, I asked the same thing. Actually, it would be great if there was some safe way to attach the pieces to the wheel wells of a delivery vehicle like a FedEx or UPS and see how it does. Real world exposure is always best. Two year test would be best - I love the test, but would like also to see an old truck used which already has rust on it. Control part, front driver wheel well, and rocker panel and elbows where the rocker panels meet the wheel wells, do not spray anything. On passenger side, use CRC front wheel well and elbow down to the rocker panel. On back wheel well, use something else and compare. Only prep would be a very thorough power washing of the areas and drying it out before application. Same for the control side, power wash that side as well. Note any washing in the winter. In April check out how each area is doing.

[@missingremote4388]

I just sprayed my rusty undercarriage with the StaBil rust stopper. On a 25 y/o GM vehicle that was never treated before. Will post a follow up KZbin video next spring.

[@joq702]

@@missingremote4388 Thanks. Did you do much prep prior to spraying? Tell us what you did if you can.

[@missingremote4388]

@@joq702 my frame had surface rust mostly. Not flakes of rust. Removed a few scale spots with a ballpeen hammer; (but ignored most). Wire brushed frame to almost bare metal. Using a wire wheel on an electronic drill to remove dirt and rust/dust from frame. Additional wooden handle wire brushes for areas hard to reach. Then, used an air hose attached to a air compressor to blow out as much dust as quickly as I could. Then spay a coat. I sprayed 3 stripes along a frame rail. Then used a medium/small paint brush to smear the lines and get full coverage - I was going to wash it but didn't - no rags, or clean wipe down ( I've only driven by this truck 300 miles in the last 6 years) but keep it running, clean & registered/insured. - really: *no prep* is required for StaBil rust stopper to work. Spray it on top of painted metal and it will stop rust.

[@davidmichael1951]

All in favor

[@barryreid7127]

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.

[@dantheman1337]

Yes this stuff seems the ticket, clear winner. Any downsides?

[@macmurfy2jka]

Dan E Garner it’s hard to get off?

[@XOneStarX]

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.

[@Herpaderpderpamufuka]

YES! Please do this

[@gskills]

Yes... what can we do if you have some light surface rust starting.......

[@WASTED__POTENTIAL]

Agreed. I'd also like to see how ACF-50 compares

[@davidmichael1951]

All in favor

[@robertm5969]

Agreed. My car is over 10 years old. I want to know that if I apply one of these products, will it "seal in" the rust and help it spread like a rubberized coating, or will it passivate it Fluid Film? The CRC and other products look impressive, but for now I'll play it safe with FF until I see the test on existing corrosion.

[@timdrake9326]

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

[@You1987Tuber]

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

[@chewykarma]

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!

[@james1939-s1c]

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

[@johnoquinn5049]

Which brand do you use?

[@quadpit]

@@johnoquinn5049 He named Fluid Film as what he used

[@james1939-s1c]

@@Dr.Ticklebum69 I reapply each fall, never wash the under body.

[@hhamilton6391]

Hi James - did any of your trucks have rust on them to start? and if so did you scrape/ sand or pressure wash before the first application? thanks! great video, but my truck is already rusty....

[@james1939-s1c]

@@hhamilton6391 no, all brand new.

[@John5ive]

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!!!

[@bullmoosepiper7732]

@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!

[@RepairGeek]

You are not the first person to say that they have had a good experience with Krown. I have no reason to doubt what you are saying that you've had good results. I even went as far as testing Krown a second time the following winter after this video thinking I had an error in my testing. The results were the same each time. If it works for you great but, other stuff would too.

[@stevel1475]

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! 👍

[@anthonygillesse7242]

Thanks for all your work Cosmoline all the way

[@joemores6196]

That's what I'm thinking :)

[@jonnyg44]

Worked well for every Russian gun I've ever bought

[@pedlpower]

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

[@donaldsmith3787]

Sounds like a great combo! How's that working for you?

[@JayyBird93]

What’s wrong with using CRC inside the panels?

[@pedlpower]

@@donaldsmith3787 Sorry for the late reply! It's working well except that I sprayed the FF in the panels in the Fall. Come Summer it heats up and runs. A little seeped out of the rear hatch onto the carpet. No biggie though. It's our beater car.

[@pedlpower]

@@JayyBird93 I think that the FF creeps into seams better. The CRC seems thicker and sticks to the undercarriage better. CRC is also more expensive at my local store so I save a little $.

[@WaterDR-tw8re]

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

[@gerryvass3876]

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.

[@MotoGPatrick]

POR15 is a paint system not an undercoating. Sort of not applied and tested as paint in this test.

[@lacro5686]

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.

[@KasparOnTube]

I hope You are right as here in Eastern Europe the Krown is kinda only available option out of those what that video was talked about and I'm gonna do it on next week for my car. Also I am very surprised about price 50USD.. here is like 179EUR (almost 200USD) :S

[@jsmith42690]

@@KasparOnTube VAT. Everything in Europe is more expensive because of VAT.

[@petrolekh]

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

[@scooterpie696]

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

[@theswissarmyman1125]

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.

[@tommenzel3591]

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 ..............................

[@seanoleary1979]

AMEN BROTHER!!!!!!!!!!

[@josephpuchel6497]

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.

[@germanboy5392]

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

[@Zombiecidal]

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

[@benjaminallen2370]

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.

[@adamcoe]

Agreed, I like the idea of combining them, as in "high traffic" areas so to speak, maybe you want something a little less likely to come off, so CRC works great, whereas in other areas that don't see as much abuse, and/or if it's an area you might want to access later and not deal with a ton of goo, something that comes off when you need it to is the right pick.

[@toddrobinson2547]

Thank you for taking the time for a very well thought out and fair, real world analysis of multiple products. I doubt a laboratory could have done better. There are many similar products, but this also covered the main methods. I just spent the last 4 days removing all the skid plates off my 2 year old 2022 Jeep Cherokee KL Trailhawk. Carefully removed all the rust (mostly at the welds). 240 grit sanded the factory paint, primed where I exposed the bare metal then applied “EZ Liner” spray on box liner. With the skid plates off I literally hand washed the nooks and crannies of the undercarriage! Sprayed the pinch welds and exposed undercarriage with more “EZ Liner”. After 24 hours of cure time I then sprayed several cans of Fluid Film into every concealed cavity I could find. Then put the skid plates back on, applying ceramic brake lube to all the bolts and contact areas to ensure easy removal for cleaning next spring. I went to this effort as this KL hasn’t really seen winter yet, as my mother bought it new spring of 2023 and it sat in her car port for the entire winter 2023/2024. I purchased the car from her estate (may she rest in piece) in Spring of 2024. It was never under coated as the dealership conned her into an Electronic Corrosion Control Module (one word, 💩). Scoping the inside of the unibody frame revealed that surface rust had already started . Hopefully the application of Fluid Film will help stop or at least slow it down.

[@ParadigmUnkn0wn]

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.

[@johnnymatias3027]

Oddly extremely smart... cant rust if it’s covered in grease

[@noobjitsu1743]

​@@johnnymatias3027Its an old trick that works along with cow shit

[@MarkThomas123]

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...

[@vintagecardcurator]

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.

[@DC9Douglas]

Same here, i use about 25 gals of Fluid Film a year for my fleet of plow/salt trucks.

[@travispratt6327]

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.

[@MOE13576]

Not really

[@markf5735]

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.

[@josepires4345]

I know this is a couple of years old so how has your experience been so far not going with NH Oil?….I ask because I have been using NH Oil for a few years now and happy with the results so far….but always willing to try something that’s better.

[@GreatDrums.]

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!

[@stevel1475]

Ya older cars don't have much access to the inner panels. So they gotta drill holes to rustproof them then plug it up. Either it you have rust holes or you have drilled access holes and a well taken care vehicle.

[@truckerrickakamanowar]

My 16 daily driver 2 door wrangler has been protected by fluid film since new. Looks new underneath actually better than new since I sprayed the whole frame with vht chassis paint then used fluid film starting in November - March. I power wash the whole underneath in spring. I wash the outside of the jeep 1 a week or so during winter usually at a no touch carwash. Awesome product. I use the aerosol cans.

[@RobertKohut]

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.

[@Johns367]

Is the crc a hard coating

[@jamesschmidt1120]

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

[@boots7859]

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.

[@SonnetGomes]

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.

[@reedstemen]

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

[@tekink8143]

Excellent test. I got a new car that plan to keep for a long time and saved me a lot of research on undercoating options.

[@cook1876]

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.

[@4orrcountry]

That's why it needs to be re-applied annually.

[@4orrcountry]

Note: cost varies, but $150.00 U.S. for medium size vehicles.

[@valleukin9624]

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.

[@klassclown]

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.

[@jjack6896]

A unique one step process with two united states patents Applies directly over rust UV resistant will not fade or crack Simple one step process, little or no preparation required No topcoat needed Brush, roll, or spray on Covers approximately 400 square feet, per gallon, per coat, depending on the porosity and texture of the substrate. A minimum two coat application is required. Directly from the site, they keep saying one step process then little or no prep and in the end two coats required. Sure is hard to believe a manufacture when they simply sugar coat everything. Makes me leery about the UV also since it said resistant.

[@jeffwilliams9086]

Great channel, really like your videos! Just found your channel looking for a JB Weld exhaust repair, and quickly found you have a lot of very useful videos, and very competent advice. Specifically I’ve recently been looking at undercoating videos in a casual and ongoing search for the way to best protect vehicles in Ohio winters, without seeing your videos…the “algorithm” fails yet again! Anyway, after watching them I found your undercoating videos to be the best, exactly what I been searching for!…THANK YOU!

[@leonwurr]

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

[@trevorterry795]

This is amazing! HIGHLY Impressed. Thanks for putting in the time for all our benefit.

[@JohnnyFTD]

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.

[@lockburner2000]

I think using both be great one thing about fluid film will keep creeping when the other will Not. Inside doors the fluid film will get in the pinch welds much more. CRC in wheel wells in high wash off places might work better. Wonder if CRC will soften with fluid film?

[@Sardonic1981]

@@lockburner2000 yeah combo would be killer, great observations and questions..

[@VexingCode]

Use both, Fluid film definitely in the doors, and any plug holes. CRC for the wheel wells that can't wash off easily

[@moultonditcher6187]

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!!

[@tac4bravo]

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

[@kovalenkoihor4325]

Not like directly. POR has special set, where you first do metal prep (phosphatic acid) and then undercoating.

[@LumenChaser]

Good luck with that, look up por15 rust videos and see what happens No undercoating works as effectively as lanolin based products especially wool wax or surface shield

[@kovalenkoihor4325]

@@LumenChaser what are you saying? No effective undercoating?

[@LumenChaser]

@@kovalenkoihor4325 I said nothing works as effectively as lanolin undercoatings meaning lanolin products are the best protectant in the industry for salty roads and this has been proven so if you don’t want your vehicle to rust out use wool wax or surface shield.. wool wax also sells HV version which is much thicker so it doesn’t wash off but still stays wet as it’s lanolin based, it is used for High wash areas

[@rdspam]

Yes, “testing” by ignoring all of the manufacturer’s directions is pretty irresponsible.

[@steveforbes8287]

This is interesting. I am working on restoring my 1998 Ford Explorer XLT 4 x 4 and I live in New Hampshire. Obviously, the rust monster had had its way with the rocker panels on my vehicle. They will get replaced soon and I need to halt all of the other surface rust that is present. Cosmoline is an old friend to many of us. Our Uncle Sam made certain of that. LOL So far, the CRC looks to be the current winner. I will be checking out the rest of your videos and others while getting the underside of my EX ready for treatment. Note: I moved from Mentor, Ohio to New Hampshire in 1980. I've been elsewhere at times but, mostly in NH. I have never heard of NH undercoating, ever! That is a new one to me and, honestly, I'm not surprised that it is a borderline failure. FWIW

[@jason86768]

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!

[@dethmaul]

Is it like paint, if the surface is clean does it need to be sanded rough for it to adhere to something?

[@jason86768]

@@dethmaul Yes. POR15 needs a rough surface to bite into for best adhesion. Their own instructions state that rusted surfaces are best (with loose rust knocked off first), sandblasted surfaces are second best. Smooth/shiny surfaces will not allow POR15 to adhere well at all, and must be roughed up with sandpaper first. And always use their Cleaner/Degreaser and Metal-Ready prep washes first.

[@skibuddy1305]

@@jason86768 if you put POR on correct it is basically indestructible. Makes your whole video a waste of time.

[@danheller9552]

Great video. Very informative. Plan to use CRC Corrosion Inhibitor on my vehicle. Thank you for taking all the time to do this test comparison.

[@scubbarookie]

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. 👍

[@jeffreymcdonald8267]

Good job young fella. I appreciate your attention to detail. I am gonna go out on a limb here....and say...your Dad was a good teacher. And he had an attentive and smart student. Thanks for the vid bro.

[@RepairGeek]

My girlfriend actually works in the coatings and paint additives industry. She supervises my tests haha.

[@jeffreymcdonald8267]

@@RepairGeek She's smarter than me for sure.

[@kyleoldham1999]

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

[@kyleoldham1999]

I don't think it matters too much! As long as it's coated

[@foreverdrift]

Cheers for this awesome video! I'm shopping for a used van, and this is my go-to resource for rust-prevention products.

[@fubartotale3389]

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.

[@ChuckWilsonWilsonsStudio]

WoolWax FTW

[@privatedata665]

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 .

[@michaelsalice9952]

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

[@debramckee3844]

unless you live near the coast in the south like a beach then you're right back here :)

[@fubartotale3389]

I'll go with the rust.

[@crisvillarreal9777]

@@fubartotale3389 more room for us ya yankee

[@VeritasInsights]

The far west (Nevada, Arizona, Utah, NM) is even better. No humidity. Cars left in the desert stay preserved for decade after decade after decade

[@mrraff69]

@@VeritasInsights I’m from Ohio and went out to Northern California years back and I was blown away by the clean 50 year old cars and trucks.

[@bloomling6414]

A very big thank you for making an amazing comparison video!!! Very well executed comparison of most of the leading brands of rustproofing chemicals. I am more well informed and I am really disappointed with the Krown since they are a national leading franchise company for rustproofing services. Now, let me cancel my Krown appointment and I'll go and get me some CRC and I'll put it on myself..................

[@ozzstars_cars]

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

[@Fight2Survive559]

Dude, you have yourself a cool ass channel. I appreciate you taking time and making these videos. Removing marketing bullshit and actually testing the product gives us motorheads a better edge in the game. Hope you are making a well deserved profit on these videos and I'll be subbing and sharing ur videos as they come out. Happy gremlin hunting - F2S

[@RepairGeek]

Thanks for watching. I just mostly record stuff that I'm going to be doing anyways out in my shop so, my videos are either hit or miss. I'm not trying to become a clone of Project Farm's channel. So I don't do a ton of comparison type videos. 90% of my videos are stuff that I'm going to do anyways so, if someone gets something out of it, cool. If not, it's not a big deal. This channel is far larger than what it should be in my opinion. I was never out to 'make it' on youtube. I'm just a guy out in his shop fixing stuff whether or not people watch my videos.

[@Fight2Survive559]

@@RepairGeek more power to you dude. Whether you realize it or not, honest review videos are something many people appreciate without voicing it. Your 10min video saves months to years of trial and error, but these videos don't trend or get the subscribers equal to their value. Whether you reach a point of relivence in the eyes of the youtube algorithm is irrelevant to consumers looking for honest, objective information on well known products. Just want you to hear it from a fan that there are plenty of people that appreciate your efforts, working in their own garages, that appreciate these videos. Keep 'em coming 👍

[@brockbookout5403]

Great video! I’ll definitely go for CRC

[@dietersmythe9649]

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!👍

[@D6Spanky]

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

[@giancarlopenaherrera7415]

How did the crc hold up? I'm planning on using this stuff too.

[@D6Spanky]

@@giancarlopenaherrera7415 I wish I could say I have gotten that far! 🤣 I have been looking at a company called Lizard Skin out of Tucson. I'm going to likely use them instead. I'm doing this on a project car so I don't have as tight as a time-line as I'd like.

[@ronw.4667]

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.

[@skyline5354]

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?

[@steve8803]

@It's the same thing. I prefer rust check, they use their coat and protect formula for the undercoating which has more of a gel like consistency and will last a lot longer than the thin liquid spray krown uses.

[@adventure-cowboy]

Thank you so much for sharing your expert investigation of these products with the most in-depth recap, process videos, detailed scientific method execution and non-bias results. I learned so much and will be going with the LPS 3 for my 2018 Tacoma in Seattle WA. Thanks again, you're the perfect example and leader of sharing quality content and support for people in need :)

[@larsdahl6594]

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.

[@JA-fn7le]

Lars? How many cans to treat a crew cab truck?

[@johnvandevusse6123]

Yes how many cans for a crew cab. Would nine cans be enough?

[@larsdahl6594]

@@JA-fn7le @John Vande Vusse I bought a gallon and a mid-priced HVLP gun, but I imagine 9-12 aerosol cans would be plenty enough for a truck. Just make sure you get extension tubes for the cavities. The biggest difference between aerosol and HVLP (IMO) is that the latter gives you a finer mist that I imagine would yield better coverage as well as being more economical in the long run.

[@joshterry9503]

Nice! Exactly the info I was looking for! Thanks for putting in all the time to make this video and save the rest of us from all that testing!!!

[@loktom4068]

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.

[@originalfrigmedic4931]

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.

[@cddsix]

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

[@rik4369]

Great video and work on this test. I have been a Fluid Flim fan for years. Appreciate the video.

[@davidmichael1951]

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

[@eddy67]

SW ohioan here - well said! I see tons of rusted out cars & trucks driving around every day and we don't even get half the snow you guys do. The salt is a killer!

[@mikebee515]

Yep bout to get some crc for that good Cincinnati salt!

[@JOHAN_PERJUS]

Really great job testing single stage products, particularly by mounting them next to the road, ingenious! Would have loved to seen them compared to a properly prepped 3-stage POR-15 as so many people swear by it.

[@jmackinjersey1]

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.

[@sageRJRJ]

This is exactly why I read comments - and go searching on forums for that matter. Thank you so much for your professional opinion. This is exactly what I was wondering and why I was watching videos on the subject. I wish every information/procedural video on the internet had a professional's unbiased and THOROUGH explanation of all the perspectives to consider. As opposed to "here's what I do so do this" which encompasses the majority of these "How To's." So thank you again, I'll be skipping an undercoating on my brand new car and washing the underside regularly instead.

[@jmackinjersey1]

@@sageRJRJ Simply keep an eye on the undercarriage as well as under the fenders etc. Keep in mind that you will see some surface rust in some places, so pay special attention to those places. If you see them getting worse, go to the dealership or find out which local Professional Body shop is CERTIFIED by that specific manufacturer to perform that type of work.

[@craiggerlach5548]

wouldn't one of these products be better than just letting it continue to be exposed? I am poor, crippled up and my classic car paint came off underside after 1 ride in winter to a Dr appointment. Was looking at cosmoline or one of the wax style coatings and thought I could wipe some ospho on it one day and paint on another wax product the next day and hope for best.. I could not hold power tools and do underside the right way, no access to lift.. and was hoping better than just letting it stay exposed... if I were still in my prime I would lift body off frame, blast everything, degrease and apply some Tamco DTM epoxy on it.. for others, sure they wanted to ask, what does the factory use, say for GM other other common domestics. Most the rides I've seen were just painted on bottom side.. I worked at a dealership and we didn't have anything special, seemed like they bought different products or had a range of them depending on what the customer requested.. my lift was next to the lift they sprayed with and I'd get in trouble when product hit car I was working on so I quit..lol

[@jmackinjersey1]

@@craiggerlach5548 I hear you, it is confusing with all of the stuff on the shelves and now the internet (what used to be limited to the television commercials and car mag ads. The main thing to remember when applying any of them, even factory applications/recoats is that the surface absolutely has to be cleaned and prepped properly. You also need to ensure that all of the factory holes are left clean/free of debris or coating. Even working in a body shop, it can be hard to find out what is and is not supposed to be covered, but the info is available to professional shops. This is one of the many reasons that manufacturers are starting to make it where body shops are Certified to be able to work on their cars, or the shops will not be able to get genuine parts, paint etc. The new and ever/always changing or improving manufacturing methods and welding/gluing procedures and alloys means that this is an important issue, and as a professional body technician, I agree with their stance on this. I mean, did you hear about the body shop that replaced the roof of the Honda Fit car, and that car was then sold and was involved in a wreck? www.thedrive.com/news/15027/couple-awarded-42-million-for-crash-injuries-after-body-shop-glues-on-replacement-roof

[@j.d.williams7125]

Actually, washing your vehicle frequently here in the Northeast is a terrible idea, as what the salt loves most is warmer water to creep into all those areas that many folks don't undercoat, rusting the vehicle from the inside out. I undercoat professionally and take off all of the splashguards, fender liners, mudflaps, rocker panel and other plastic trim if equipped to thoroughly get into these areas. Personally, I use Fluid Film but I think the key is regular (yearly) cleaning and application, if it's an oil-based product. I've seen dealer undercoating, and, while it's effective where applied, they don't take off ANYthing to spray behind. I'm sure their fine print excludes them from responsibility down the road.

[@BigAgitator]

Excellent review! As an auto mechanic, I like MP HD the best when compared to fluid film and others. Thanks to your video, I'm gonna' save a chunk of $$ and try the CRC!

[@trentriver]

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.

[@chrstphrr]

I was just digging around after watching (out in Alberta), and found that NAPA Canada has that CRC product for less than all the resellers on Amazon.ca or .com, or other sources. I'm leaning toward one of the cosmolines, and treating over with fluid film over that. I may lean toward the LPS-3, if the cost of the other two together aren't less expensive, if I can find a decent and readily available source north of the border.

[@mikerussell5454]

@@chrstphrr Any luck finding cheap options? I am GTA area but I am sure many of the same vendors

[@johnqpublic9074]

In YYC, find anywhere that sells RP 342? Looks like a winner for our salt and rocks...

[@dbradshaw9141]

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

[@backyardmech]

Great video - you put some time and effort into it; well done !

[@dominofive5075]

Dude!!! You win any argument on rust restoration

[@davevirag5423]

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!

[@johnqpublic9074]

It's a Canadian product only, the continental types won't know what your talking aboot... lol

[@shamwaymoonyos9578]

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 :)

[@jimdiavastes]

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

[@jodyg7452]

correct....

[@Lexus_Robb]

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. 👍

[@sthomas7211]

I used the Waxoyl products, and am very happy. I also use fluid film to coat my shocks and other miscellaneous areas.

[@trevcessna1723]

Great video and thanks for taking the time to review these products!