Does anybody still under coat there trucks? I had my 99 done when I got it, March 98. I sold it in 2014 and it still looked pretty good for the miles it had on it 220 ish. My 2011 I bought used, and when I sold it, in August it had rust showing on the quarter panels. That one only had 113,000 miles. I am supposed to take delivery in the next week and told the salesman I want it rustproofed today. He said he would send it to the same place I was thinking. Does anyone else still do this? I am planning on keeping the truck long term. Kevin

 

The body is aluminum, unlikely that it will corrode in any appreciable way.

running gear and frame are still steel, so potentially they could rust through, so perhaps that is worth doing. Depends on where you live.

 

I live in Northeastern Ohio and would recommend it. Had a 2009 Ram that got really bad after a few years. Just bought a 2020 F250 Superduty a week ago and it's getting undercoated/rustproofed tomorrow. I think it's worth it in the long run. Can't hurt, right?

 

Yeah, I forgot to mention I am in Michigan. It also acts as a sound deadener..I have seen aluminum snowmobile trailers rot out fairly quick.. I like how ford says "no more red rust" Yep, aluminum oxidizes, lol. Kevin

 

I used fluid film on the frame. Sprayed a lot inside the boxed frame rails and anywhere salt can enter but not be easy to rinse out. And anywhere I found bare metal. Aluminum or steel. Im going to do it again each November. I worry about the salt laying inside the boxed frame doing its thing all year.
Also the electrical plugs around the rear of the frame. I dont know if Ford did anything with them... but they hold water. Guys were having electrical gremlins which turned out to be these connections shorting or even rotting from salt in a short time.
When I read about it I had like 250 miles on my 19 and when I checked them they were holding water. I rotated them a little so they could drain better and lathered them up with dielectric grease.
Theres main wiring harnesses under the door sills in a channel. I had a bottle of bleach rupture on the back floor. All liquid that hits the floor runs towards the door and drops into that channel. It cant get out. So as I was rinsing and flushing the bleachout I had to drill a hole up near the front door sill so it could drain out. When I was done I Fluid filled the hole and left it open for future drainage. 1/4" hole. I didnt drill the drivers side yet but I might.
I have the vinyl floor with Husky liners which go over the sill. To help keep salt water from entering under the sill there.
I think under coating the body would be a waste. Aluminum will corrode from the salt but not like steel. Might make good sound deadening.
I had Peterbilts with 400,000 miles run in road salt for years. I never saw anything worse than some paint peeling with white powder underneath.
Time will tell but they seem to be holding up pretty good so far.
My 07 GMC had 126,000 when I sold it last year and the one rear wheel well had rust through. It started as a 1/8" paint bubble and 4 months later the wheel well looked like crap.
When it comes to long term...On my Ford I worry more about the electrical and computer complication than body rot.

 

I've heard applying an undercoating can actually make things worse by trapping moisture.

I used a metal protector - Amsoil MP HD and sprayed it all over the frame, axles, etc to hopefully slow down rust. Supposed to last a few years before needing applied again..

 

That’s very true if you use paint or a rubberized undercoating. Zeibart is the most famous for ruining cars & trucks in the name of “undercoating”.

The best type of undercoating is the apply yearly or bi-yearly oil/grease based. Being either Fluid Film or Woolwax (lanolin based) or Krown, NH Oil, or a concoction of used oil. This type of undercoating soaks into all the nooks and crannies of the frame/body and really helps with rust.

Last year I applied a healthy dose of Woolwax (kellsportproduct) which is very similar to Fluid Film but a little thicker to reduce washoff. So far a year later and my undercarriage is still completely covered and rust free. This is in the northeast rust belt as well. The only downside is it is not clean. Has attracted some dust/dirt. Also any time you’re under the truck you get the coating on you, so it’s messy. I rather have that mess though, and still have a frame in 15 years.

 

See if there's a location near you.
I live in Ct. with VERY corrosive crap on the roads.
My 2013 has ZERO rust anywhere.
https://www.krown.com/en/

 

My Father-in-law has done the oil based yearly on his truck. It’s over 20 years old and has no rust. (Buffalo winters)

 

I've been doing fluid film on my Super Dutys and my wife's Wrangler. Takes maybe an hour each and I do it once per fall then don't do any undercarriage washing with soap for the winter. Seems to be holding up good and the steels looks great.

 

I like fluid film just be careful as it will swell rubber seals and possibly plastic. Krown looks good though I've never used it. Motor oil sprayed on with airless sprayer works well under trucks/cars to prevent rust if you have a drop cloth and time to let the excess oil drip off.

Bottom of door seams and around hood and tailgate seams I spray WD40 to displace moisture and it's easy to brush off with soapy water in the spring.

Keep natural dirt traps (like inside the wheel wells) clean and don't allow dirt to build up and keep these areas damp.

As mentioned, I'm also cautious of any undercoating if it forms a film (like the rubberized version). It can definitely make things worse. It cracks just a little and causes permanent salt traps that never get washed out.

Can't comment on aluminum bodies but aluminum wheels sure do corrode if their clear coating is scratched...it's like they get termites that eat right through the wheel. Most tire shops now use adhesive wheel weights. The clamp on weights damage the clear coat, results in corrosion, and lead to air leaks through the wheel rims.

 

I sprayed my new truck last weekend with " Corrosion Free" rust treatment. I had been using it for years on my last truck, seems to still be on there after a year when I got to do the next coat. I had been using their cheap DIY sprayer. This year I bought their "pro" sprayer. It comes with several wands and attachments for spraying inside doors and frame rails. Since the pro gun atomizes the fluid more, I used significantly less fluid to coat everything. Its cheap insurance, and although makes working in the vehicle a little messy, its nice not to deal with corroded nuts and bolts when doing work..

 

Boeshield T-9. https://boeshield.com

Developed by Boeing for aluminum aircraft but marketed for Marine, Cars, trucks motorcycles, RVs etc. It’s a thin film that creeps into all cervices and leaves a thin waxy residue.

Another one is a corrosion-x https://www.corrosionx.com/collectio...omotive-and-rv

Another one is ACF-50 Lear Chemical Research Corporation

I’ve used all 3 on aircraft in a Florida. It keeps them absolutely corrosion free in salt air corrosion prone coastal Florida. It will drip for a while but it will prevent and stop aluminum corrosion or steel rusting. It should be applied at least every 2 years.

You can stay it on directly or use a compressor air and a wash gun to fog it on.

Wear a respirator so you don’t inhale the oily fog and screw up your lungs.

 

I will never again use undercoating after a bad professionally applied experience with Ziebart.

They screwed up my new Nissan 300zx by spraying inside the rocker panels and clogging the drain holes. 2 years later the rocker panels rotted out due to the drain holes being clogged with undercoating and the rocker panels were FULL OF WATER.

When I brought it back for a warranty claim their offer was to refund my money rather than repair the damage they caused.

 

Every time I change the oil I wet a rag with the old stuff coming out and wipe the frame down. No frame rust in 3 years 66k miles. I live in NC, your results may vary. It's free and easy.