New member here.
This may have been beaten to death by now but being new, hopefully I get a mulligan.
I just inherited a "new to me" 2015 XLT with 35,000km on the clock. The previous owner (my late father-in-law) didn't believe in rust-proofing. Especially an aluminum vehicle.
I however, have had my more recent vehicles rust-proofed and believe it's a sound investment here in salt land. Having just crawled under this gem to do an oil/filter change I've noticed that there is rust appearing on the steel frame structure. I'm planning on taking it in soon to get sprayed and was wondering what the general consensus is regarding doing so.
-Basic under-carriage spraying OR the full rust-proofing treatment?-
I will be going to my local Krown rust-proofer to get things done.
Thanks.

 

I've worked at ford truck plants and have seen how they paint vehicles now. They actually submerge the body parts in different solutions before paint and run a charge through the metal so the paint lays evenly. This was over 20 years ago so I know the process has had to improve. The frame is also e-coated. I think rust proofing has been a waste of money for a long time now. As long as you periodically wash your truck I think that's the only thing needed.

And before someone shows a pic of surface rust under the hood that's all it is surface rust.

 

I agree there is over 100 years of cars and truck frames still going strong. I suspect the body will fall off before a frame rusts

 

Well...around here you are lucky to get ten years out of a steel vehicle body before rust takes over unless you rustproof. As far as frames go, 40 years or so.

 

I lived most of my life in Michigan where salt is used regularly so I stand by my opinion.

 

I have a 15 also,
there be rust on the fasteners, and components, bolted to the frame and body

 

I just got on board with rust proofing with my 2019 I just got. I am moving from MD back to MA and I've seen what the salt does to trucks up here. I know the frame won't rust to the point of failure but a lot of other things will and will make it difficult to work on down the road. The frame and the truck overall just looks better the longer it can look new/surface rust free. I applied Wool Wax to my truck myself. I ordered their 5 gallon kit for around $200 and only ended up using a gallon. For the money, this should last me 4-5 winters of protection. I coated the frame, axle, suspension parts, brake lines, etc. The process took me about 1.5 hours so it wasn't a huge investment in time either. Time will tell how effective it is.

 

There's an article, youtube video, where one person sprayed underbody coating protection. Over the years, salt and water got trap between the coats and deteriorated the frame.

 

My second new car was an '86 Mustang GT. I bought the dealership version of rustproofing which was a thick black coating which got brittle and flaked off within a few years. I would not get this type (wax or asphalt based?) again as I think it WOULD trap dirt and moisture between it and the metal thus promoting rust instead of preventing it. That car rusted badly in the six years I owned it.
Krown is more of a thick liquid that creeps slowly and doesn't solidify. It makes working on the car body a bit of a mess and mechanics dislike it for that reason. But it seems to work well. Like I said, I've used it on my more recent vehicles and 10 to 15 years later...no signs rust. And I only get it done once every two or three years. Four sometimes.
I'm not at all affiliated or trolling here.
I do agree with pjazz that washing goes a long way.

 

I can definitely see that causing problems. I got my coating on there when it was brand new and in the spring it will get a thorough pressure wash which will end up taking most of the coating off the surface. I'll repeat in the fall and apply more wool wax before salt hits the roads. I'm hoping this strategy keeps it in good shape