Undercoat, or NOT to Undercoat ?

How long does it last before needing to re-apply, and can you feel it on the surface after it dries?

 

I applied a heavy coat to it about this time last year and just checked it a few days ago, and it still looks brand new underneath, so I'm planning on every two years. As far as feeling it, it was slightly tacky after the initial installation, but now it seems completely dry. You can see in the pics i took last year some of the yellow haze on the sway-bar bushing brackets. Hope this helps.

 

How many cans did you end up using?

 

I ended up using 6 cans in the end, which was enough to do everything including underneath the bed.

 

I was using Fluid Film for years on my 2 cars and 2000 Tundra which was instrumental in keeping the frame rust problems to a minimum. The down side is that overspray or leakage of Fluid Film onto the softer rubber components like door, hood seals (weather stripping) ends up absorbing it turning it into an inflated mess. Another downside is that most of it washes off by the end of winter from the car washes and constant road under sprays so must be reapplied yearly. Since I have a new 2020 TRD Pro with virgin underside I wanted to try something new. So this is the first year I am switching over to trying Amsoil HD MP. I used 12 cans on my new truck and 6 cans a piece on the Civic SI and Acura RL. I coat everything, not just the frame rails and suspension components but the entire underside, removing all the rubber grommets under the rocker panels and spraying in there, door jambs, hinges, every nook and cranny where salt and brine can collect and eventually start the corrosion process, coated the wheel wells, inside bumpers, tow hitch, brake and fuel lines, brackets, heatshields and bolts and, removed the skid plate, spray up and everywhere in there..... With the Amsoil your limited to where your non flexible rubber straw can spray. So for the hard to reach areas, like inside the bottoms of the door panels, above the trans and above the gas tank I used fluid film with a 16" flexible hose that has a spreader tip allowing the lanolin to spray in all directions and coat everywhere -->

Woolwax® 24" Aerosol can Spray Wand with 360° Nozzle

https://www.amazon.com/Fluid-Film-Spray-Extension-Wand/dp/B00CLUGXFI . I used this flex tube inside the boxed frame rails (the front 1/3 of the frame) and popped out the rubber grommets in the doors on both the inner and outer sides to run the tube down and coat the inner bottom panels. I have a buddy that has a side business applying Fluid Film to cars so I learned a lot from him. Don't forget under the hood, and lightly spray any exposed nuts and bolts and hose clamps and brackets. All those rusted on my 2000 tundra from moisture and salt spray that would work its way under the hood while driving throughout winter so I learned from that and determined to make them last on this new truck. Amsoil (cosmoline) unlike the more liquidy Fluid Film (lanolin) in my experience has been safe on all plastic per my buddy who has been using it and just leaves a waxy coating on the surface of plastic/rubber rather than being absorbed like Fluid Film. In the end I used 12 cans of Amsoil HD MP and 5 cans of Fluid Film on my truck. Lets see how long each lasts Oh, I used 12 cans of Amsoil total over the course of 2 days. I went back over a second day approaching the truck (on ramps) this time from the front instead of rear and saw a bunch of places that I either missed or I left only a very thin coating on since the amber color looked light so I went over everything again, second coat just to be sure. A case of 12 Amsoil HD MP cans if you sign up for the Amsoil club ends up being a little less than $130 shipped

 

I finally had time to apply Fluid film to my truck. I got 6 cans from Amazon, but only used 4. I was a little conservative when applying it. Now the waiting game begins.

 

Yeah, but I'm sayin', that TruCoat, you don't get it and you get oxidization problems. It'll cost you a heck of lot more'n five hundred

I'll talk to my boss. See, they install that TruCoat at the factory, there's nothin' we can do, but I'll talk to my boss.

made me think of Fargo. Obviously I don’t have any undercoat on mine.

 

I have used ACF-50 for years with good results on my trucks and motorcycles. It creeps. My '20 PRO has been through one nasty winter and still looks exceptional. I tried Krown and Fluid Film on previous trucks, both professionally applied, and went back to doing it myself with ACF-50. I don a hazmat suit, do two spray-the-shit out of everything & wipe sessions, and settle in for our long winter.

 

I'm doing either Krown or Woolwax in a couple of weekends from now. Have used Krown for many years with good results, never used Woolwax.

 

Another vote for Krown here. Did to my 2016DC since new and was happy with the results. My 2020 is getting the same.