Fluid Film Black Non-Aerosol, Long Lasting Corrosion, Penetrant & Lubricant, Anti-Rust Coating, Protects All Metals in Marine and Undercoating in Automotive & Snow-Handling Vehicles, 1 Gallon

I purchased my first can of Fluid Film back in 2021 after purchasing a new F-150. In short, this stuff works, and works incredibly well. Sprayed using a 8 gallon harbor freight air compressor and the Kellsport Woolwax pro undercoating gun. I tend to use 1/2-3/4 of a gallon each spray. My first two applications I have done were with the original/yellow/clear Fluid film. A major benefit of that is it doesn't alter the appearance of parts very much and you can visibly see what areas may be starting to rust easier. The disadvantage is that it doesn't flow as well and is thicker out of the container, but that potentially aids in keeping it on. I spray my truck twice a year which is probably overkill (pre summer/beach driving, and pre winter/salt roads). Had I done my truck earlier the first time there wouldn't be a speck of rust to be found. Since my initial treatment, I have no seen any new areas of rust formation. I even power-wash the underside of the truck prior to treatment and still cant get the original coating off. It adheres very well. I'd say the only major downside is that dust and dirt stick to the coating and can make the underside look a little dirty, and if you go to work on your vehicle it may be a little messier than if it wasn't coated. Important information: -A respirator is absolutely necessary when spraying this stuff, goggles too. I wear a full ace 3M respirator when doing this and the overspray gets everywhere. I know it's fairly natural stuff, but it cant be good to get it in your eyes or inhale it. You can see the atomized product in my video, it gets everywhere. -Clean the underside/frame very well and make sure it is completely dry before application. -Either cover, or be prepared to clean anything you don't want what is essentially oil on. If this gets on your brakes your stopping power will be reduced. -Proper application on a Ford F-150 (Inside and out of frame, and any exposed steel) took me about 3/4 hours without prep/cleanup. -Cleanup: the overspray gets everywhere. Be prepared to cover everything or clean it up. That includes the ground under the vehicle, the outside/paint of the car, and if you do it in a shop... everything in there as well. Highly recommend outdoors on a day with low to no wind. I find it has been well worth the investment and after 2.5 years of ownership, multiple summers of beach driving, and salt sprayed roads, my frame and axle look brand new.

Just finished applying this to the undercarriage of my 2010 Silverado. I first pressure washed the bottom and cleaned all the old existing OEM coating off. Then primed with spray paint. Then painted black. And finally topped everything off with this black Fluid film. So a couple of things - this stuff is fairly think. Almost like a pudding consistency. Could you spray it? Possibly if you thinned it out or heated it up. I chose to apply with a foam brush and it worked great. Filled up a little 16oz paint cup with a brush and rolled under the truck and applied. You can actually apply it fairly thick without it dripping. I am used to using the aerosol can so the consistency was something I noticed. Secondly - the black color. I personally think it's awesome they offer this for literally a couple bucks more than the original. It goes on a glossy black - much better than the waxy looking original. Especially when you are applying to a black surface or something with a bit of rust. The black will cover up the imperfections and the deep glossy look makes it easy to tell where you have applied. I used probably 1/5 or so of the gallon to completely do the frame/leaf springs/cross members/rear axle etc. So the gallon container should last a fairly long time. On top of that, the fluid film I've used in the past would stay on, even if if got wet. It would take a hard direct spray to remove it. So I'm anticipating the durability being really good as well.

Used this for undercoating my old truck and it works well. I used an air sprayer to apply it and it covered all the surfaces and cracks good. Great for protecting the frame in salty areas. Solid product if you want to keep your vehicle rust free.

Work's well slows rust

So far, I have only applied the product. The can came sealed and was overall a good shipping experience. I used the WoolWax Pro spraying gun to apply the fluid film and it worked quite well. The product went on and has seemingly stayed on. I don't know much about this stuff, but a mechanic I trust told me that this would work quite well on my truck for the Midwest. If you want to be safe, just coat everything. This product can't harm your vehicle to my knowledge. In other words, feel free to go crazy with this stuff on your undercarriage. My only complaint is that it smells like cow manure. However, that hopefully encourages everyone to use a respirator, which I would recommend. Safety goggles will work, but a face shield would be ideal. (almost) 1 year update: This product has worked wonders. I had the coating applied in late fall and never washed the undercarriage. The coating is still there and I believe it held up well to the Midwest salt roads. I highly recommend this product and will soon buy another gallon for a new coating this fall.