Rust on my truck frame

[WA1DH]

My 95 GMC 1500 is used during the winter when the roads are covered in salt, and also during the summer to drop small boats at boat ramps and on the beach (salt water). I average about 3k mi a year, so I want to make sure my frame outlives my engine. Last fall (October) I sprayed the entire frame with Fluid Film. I also did the rockers and cab corners from inside the cab. Almost a year later most of the coating appears to be gone. I have some rust on the rear frame rails and the point where the bed attaches to the frame. The rest of the body and frame are in great shape. These are the worst spots:






I'm wondering what my best options are for tacking this. My ideas:
-Continue Fluid Film every fall (as I've been doing) and don't worry about it
-Fluid Film every fall, plus do it again in the spring before I hit the boat ramps/beach
-Remove bed, clean loose rust, POR15 everything
-Remove bed, clean loose rust, spray paint everything with Rustoleum/other paint product

Thoughts?

 

[The_Jeff]

Grind off (with a wirebrush on an angle grinder) the flaky stuff then hose it down with fluid film.

 

[SumpChump]

The fluid film in buckets is thicker. That's a possibility. Also applying it and having time for dirt to adhere, such as drives down a dusty gravel road. Seems counter intuitive. The FF is expected to basically be gone from high spray areas by winters end. Seems to be just how it is.

I have found that a thick product like Corrosion X (HD) version. Collects sand and dirt collects rapidly into a protective filth. Boeshield is good but thinner. I like that the FF is more "natural" and gentler on materials.
A third option is TC-11 if I recall the name. I used it on a garage door track and some got on the door front. Thin but it sure attracted the small dirt nicely and soaks deep.

With a '95 another option is a used oil or used oil and kerosene sprayed diy option.

 

[JHZR2]

I'd grind it to a resaonable level, use a zinc phosphate or similar prep after degreasing, then spray paint it. Then coat with FF or spray oils or whatnot.

You want to stabilize the surface rust first. FF is not a magic cure all, IMO.

The frame was probably originally wax dipped.

 

[buck91]

As mentioned above, FF is an annual task. Sure it will still be in placed like inside rocker panels or members, but it washes off pretty quick from exposed areas. I'd just keep spraying with FF and make sure you get a good, dusty dirt road for a couple miles after application. Though sometimes depending on your area (and recent weather) that can be tough.

 

[Pop_Rivit]

Originally Posted By: WA1DH
My 95 GMC 1500 is used during the winter when the roads are covered in salt, and also during the summer to drop small boats at boat ramps and on the beach (salt water). I average about 3k mi a year, so I want to make sure my frame outlives my engine.
Thoughts?


You have a 20 year old pickup that is used in the worst possible conditions, and from your description you've only recently begun trying to slow the rust down. Quite honestly, since it's a 20 year old pickup and given the amount of rust in those photos, anything you do at this point is a bandaid on a broken arm. You might slow it slightly, but unless you do some serious metal replacement (which isn't worth it on a 20 year old pickup) then you'd be better off just keeping an eye on it and planning for the purchase of a newer pickup in the near future.

 

[Donald]

I have read that CarWell lasts longer than FF but have done no testing. CarWell suggests doing it in the spring as that is when most rust occurs.

If you have areas you can easily access then you can treat with a rust converter and then POR-15 or Eastwood Rust Encapsulator. But those can be chipped by rocks or chunks of ice. And there are areas where you cannot get to, and can only be sprayed with a wand. They will still need a CarWell or FF.

 

[ryanschillinger]

Wire wheel it or sand a bit then spray it all down with rustoleum rusty metal primer. The red stuff.

 

[zzyzzx]

Throw it away and get one of those new aluminum Ford trucks.

 

[HangFire]

SumpChump is right, you want FluidFilm NAS, which is thicker.

I'm with JHZR2 that paint is needed. I'm doing more or less what he said on my Dakota. It's a long term project. Very long term- it will never be finished, until the truck is retired. The body is still clean and unrusted, but the frame is starting to show a lot of surface rust.

I power-brush (cup shaped wire brush in a cordless drill/driver), paint with Rustoleum Rust Reformer black, then after it cures hit the whole thing with FluidFilm NAS. At some point I will take the bed off, but not before I've done everything that can be done underneath. I plan to replace all the rubber mounts and brake lines when I have the bed off. If I have to do any any spring/mount work I'll do that at the same time.

 

[stephen9666]

The FF on my Nissan's frame held up pretty well. It didn't all wash off. There's still clearly a visible coating of FF. I sprayed it in November and drove it all winter.

Still, I would say a yearly touch up before winter is a good idea. That's just the way it is with many oil-based undercoatings. Unless they're very, very thick, they will wash off over time.

 

[The_Jeff]

Originally Posted By: Pop_Rivit

(which isn't worth it on a 20 year old pickup)


The OP didn't ask if what was worth what.

 

[supton]

I am of the opinion that FF NAS is twice a year. Definitely in the fall, before winter sat; but touching up in the spring is good too.

But it just slows down the inevitable. Which I am ok with, ideally in the end everything has worn out, and perhaps a rust hole makes the decision easier.

 

[SatinSilver]

I'd have FF applied by a professional which will coat the frame with the thicker stuff. That should stop the rust in its tracks. Should run about $100 or so. Otherwise order a gallon container if they sell the thicker stuff in that small size and brush it on all areas that you can access. Use the aerosol for the hard to reach areas.

 

[supton]

A gallon of NAS is like $50 on Amazon.

I just gave in and bought the five gallon bucket. Seemed like I use at least a half gallon per year.

 

[Tzu]

I like those year trucks and see why you want to keep it as protected as you can. I would continue to Fluid Film the truck and coat it as much as you can. I like doing the undercoating at home during a hot, dry week which I think allows the product to creep and soak in better.

It is a yearly task of doing it, but in time the product should build up and then just some touch ups are needed on the high wash areas. I sprayed our old body style 2000 K20 work plow truck's frame with different sprays over the years to see which held up the best. Non detergent oil simply washed away in a short time. Carwell did okay overall, but it did not bead water after a few months anymore. I would use it exclusively inside doors, fenders and voids only as it is quite thin in viscosity. WD40 basically did NOTHING. End of story. By far, the Fluid Film held up great over the winter and that proved to me it seems to be the best option.

In the spring, hit the high wash areas again with a spray can of FF and call it done. I've never used the gallon size, just the spray cans from Autozone.

 

[WA1DH]

Thanks for all the info and opinions. I think I'm going to stick to the FF routine but clean off the existing rust and apply some rust converter/paint on the rails and obvious spots. I will keep an eye on how it's holding up.

 

[B20z]

That last pic is pretty gruesome. You might want to address that ground.