Best rust coating for steel frame (Off-topic)

[Peregrine1983]

Posting this in the off topic forum... The subject is related to boats as anti rust coatings for steel are something folks know about here.

I’m looking for a spray on rust inhibitor that I can use on the steel frame of a truck. This is a truck that endures salty roads in the winter and salty air year round. The truck is sort of a classic (at least in my mind) and came from a dry warm place where rust isn’t a problem and so it’s currently quite clean and rust free and I want to keep it that way.

Would love to hear the forums recommendations for great steel rust inhibitor that can be sprayed on.

[Lake-Effect]

Originally Posted by Peregrine1983

Posting this in the off topic forum... The subject is related to boats as anti rust coatings for steel are something folks know about here.

I’m looking for a spray on rust inhibitor that I can use on the steel frame of a truck. This is a truck that endures salty roads in the winter and salty air year round. The truck is sort of a classic (at least in my mind) and came from a dry warm place where rust isn’t a problem and so it’s currently quite clean and rust free and I want to keep it that way.

Would love to hear the forums recommendations for great steel rust inhibitor that can be sprayed on.

The best vehicle rustproofing that I could find, especially for underbody and frame, is annual oil spraying. It's something that penetrates existing rust, displaces water, and remains active - it continues to penetrate and creep - whereas a coating is static and can flake off.

There are several different products in this category. I've liked Krown, it really seemed to get into everywhere. On the internet somewhere is a recipe for a homemade concoction of parrafin, mineral spirits and mineral oil. You grate up the parrafin, dissolve as much of it as possible into the mineral spirits, add a touch of mineral oil, and spray generously. It will travel and penetrate, and when the mineral spirits evaporate, it leaves a waxy sludge to protect.

Google "homemade rustproofing" - you'll find tons of suggestions.

[GordMay]

There have been several tests, run by the Canadian Army, on which rust proofing product provides the best protection. You can read the 2006 report here.
They found that Corrosion Free was almost 90% effective at inhibiting rust, even in the harshest climates.
Krown was about 70% effective, and Rust Check was rated at around 60% effective.
☞ http://cradpdf.drdc-rddc.gc.ca/PDFS/unc53/p526285.pdf

[Peregrine1983]

This is why I love this forum. Thanks guys!

[rbk]

Also consider a flexible undercoatings. Far less prone to chipping and has the added benefit of sound attenuation. I know a few guys that rhino liner'ed their undercarriage but have also seen off the shelf stuff work great.

[Peregrine1983]

Just ordered some of this Corrosion Free stuff in aerosol cans. Based on reviews it sounds like it’s an oily spray that does not dry. Will report back after application.

[roverhi]

Back when I had a Series Land Rover addiction, a product called Waxoil or a home made equivalent was the go to anti rust treatment for their light gauge steel box frames. It's oil with bees wax to give it staying power. May be available commercially if you aren't the home brew type.
Homemade Waxoil

[hugosalt]

Before applying Corrosion Free
you would be well served to look into/consider POR-15 .
Can be sprayed, well regarded and used by many pros.
You will NOT recoating every year or two.

[flyingnut40]

I'll add one more for Por-15.
All the car restoration nuts up here use it.
They understand that water (being the universal solvent) breaks down most things (including most paints) and por-15 actually gets stronger..... kind of unique in the paint world.
When I got my cast iron keel professionally sand blasted the first thing I put on it was por-15. After that a couple coats of e2000 primer.
I wish I could say the results were amazing but I sold the project a year later in favour of a ready to go boat.
Do your research and you should discover an almost cult following for por-15.
YMMV
Dennis

[ronstory]

Yep, you got the answer. POR-15, the best paint for a rusty surface I've ever used. It's really hard once cured... so be careful where you put it. I dripped on driveway 20 years ago... and it's still there.

Follow their prep instructions for etch and don't be afraid of a bit of surface rust, the most favorite thing to for POR-15 to attach to is a rusty/etched surface.

Not UV stable, so it's in direct sunlight I'd put a top coat otherwise it goes chalky.

[Lake-Effect]

Originally Posted by ronstory

Yep, you got the answer. POR-15, the best paint for a rusty surface I've ever used.

A good surface coating is an important factor in corrosion protection, so I would agree it's appropriate for protecting the exposed areas of a truck's frame. But I would still finish off with an all-over application of a runny wax or oil anti-rust product, because that creeps, and continues to creep into every seam, nook and cranny, it penetrates into any rust, and it will self-heal later in the event of a stone impact, scrape or chip.

[kenbo]

POR-15 is a good product but it's only a moisture cured urethane (MCU) paint. The only difference is that POR-15 is very expensive with effective marketing to a niche group. Any quality MCU, Sherwin Williams et al, will do the same job if the surface is prepped by degreasing and etching.

[EcgecgAdoxy]

I also use Corrosion Free and the results are better than I expected.