Contemplating having the frame and whatever sprayed under the truck (if it ever gets here). Really would like to keep the black stuff black and looking new for as long as possible.
Has anyone done either of the two or another option? Thoughts, Pros/Cons. Hows it hold up? Waste of money? What can I expect to pay?

Thanks

 

I dont have a 250 yet but my ram 1500 first owner had an underbody spray applied when new 5 years ago. I live in ne ohio and drive tons of miles in bad weather and my truck has next to zero rust underneath. All bolted parts still come apart cleanly. I am very impressed with how it has prevented corrosion. I cant remember the company name offhand but i plan to use there services with my new truck purchase.

 

Yes. Fluid Film. Based on the you tube videos I watched they both seem to work great at rust prevention. A couple things to understand:

1. The underside of your truck will have a thin coat of waxy (oil like but not oil) substance applied to it and it is designed to stay wet to the touch. It's not going to dry. The underside will be forever greasy so if you have any work to do to the under side like suspension upgrades or wiring of lights etc. I would accomplish that before applying the rust prevention substance.

2.You should avoid washing the undercarriage. The goal is to prevent rust and its accomplished by keeping water and salt off your truck parts. When you wash the underside you are slowly removing the barrier and it will keep the rust prevention from doing its job to the max.

3. try to make sure the underside of your truck is as clean as possible before application.

I had mine done about 8 months ago maybe so I don't have any long term face to face results to share. You tube is filled with long term tests completed with a bunch of different rust preventers so it can be your friend.

 

https://www.ford-trucks.com/forums/1...l#post18244549
https://www.krown.com/en/

 

I was curious about thinning Fluid Film to spray, so I found the FAQ on their site yesterday. Here's what they say:

"The first recommendation is to thoroughly mix the product. FLUID FILM is thixotropic, and will get heavier upon sitting. Achieving room temperature with the product will help as well. If a thinner version is wanted, start by mixing a small amount of vegetable oil to the product until the desired consistency is reached. It is not recommended that FLUID FILM be used in a pump type sprayer even after thinning. Airless paint spraying equipment is what is recommended for proper application, applied at approximately 2000 PSI as a minimum."

 

Another vote for Fluid Film! I've been using it exclusively for at least 15 years. Four applications per year...at the start of each season. That's probably overkill, but it's cheap insurance.

 

One comment about Fluid Film, from their FAQs: FLUID FILM has no adverse effects on plastics. Caution should be used around non oil-resistant rubber goods. May cause swelling. ...I don't know how much non-oil-resistant rubber exists under our trucks, but something to think about.

 

I have been using Krown for over 30 years on all my vehicles. only spray once per year, Did my chassis "ONLY" on the my 2017 right after I got it. It was $70 Canadian. To do the entire 2008 F150 it was $135. So it should be half price. I have never had rust develop anywhere on any of my vehicles. I have them spray the underside but not the oxygen sensors. They do cover the coloured shocks and I am okay with that. Krown does a good job. They have asked me if I want the inside door panels and engine compartment done, but I decline. Only the underside !!

 

 

I don't believe it affects rubber. It has never affected any of my rubber products, There is spray on electrical wiring and connectors everywhere. It is a light oily film. I believe it actually helps to stop water from getting into the connectors. It will absorb dust in the oil and actually provides a soft coating.

 

 

When the vehicle is all steel I do inside of the doors and panels. Since this truck is aluminum I don't have them do those areas. On my 2008 F150 they sprayed the inside of the box panels too. Had to open the tail lights to spray inside. If you don't want your steel parts to rust, I recommend Krowning those areas. Regards

 

I have never had rotting or rusting door panels, or tailgate, or frame. They salt the roads here all winter

 

 

Berkebile Oil's PFC. Watch the salt spray test comparison video.

https://www.berkebileoil.com/pfc-undercoating