Best undercoating for salt driven cars?

[speeder]

I'm going to be running a couple of older rigs in salt country this winter, both are rust-free as of now but not built to be rust resistant like newer cars are.

I also know that there is no way to truly rustproof a car in MN., (I grew up here), just trying to do what I can to slow the progression. My plan is to steam clean the crap out of the undercarriage and wheel wells, sand the pan down and coat w red oxide primer, then undercoat it and lots of trips to the coin car wash in winter.

It's actually possible to severely limit rusting w fastidious power washing of vehicles here but most don't do it. The coin car washes here pump hot water, it's awesome.

I'm thinking of something I can brush on? I know that Wurth used to sell one, any experience here? Fire away!

[dlockhart]

The sprays look interesting for getting into the nooks and crannys that always seem to be rust issues. ( like the wheel arches on ford superduty boxes )

Cosmoline for Sale - Cosmoline Direct Rust Preventives, Sprays & More

[Tobra]

Cosmoline is what they use on guns, should work well. My uncle used to spray oil on the underside of his in Nebraska.

[fastfredracing]

We have a few places that do used motor oil undercoating. They mix something else in with it to thicken it up a little bit. It constantly runs, never hardens and gets down in all the little nooks . This is by far the most effective thing I know of. It is super messy, and you will hate working on your car after this , but it works . The people who I know that use it , seem to have the best luck with rust prevention.
Without anything applied, your cars will turn to dust in two seasons here .
I think there is also an undercoating product called LPS, same deal, it never totally cures. It will drip out of the seams on a hot day .
Welcome to the rust belt !

[1990C4S]

Transmission fluid, Varsol and wax.

Heated slightly it sprays on and stays in place.

[fastfredracing]

Yes , and lots of washing. I do the same thing, I try not to let any of that crap build up in the wheel wheels, and on the rocker panels .
Every few days , $2.00 at the car wash, and you are good to go . Gawd, I hate winter . Just around the corner

[speeder]

Thanks! Used motor oil won't work for me, too messy and I'd be power washing it off all the time. I'll look into the cosmolene.

[Tim Hancock]

Fluid Film.... I bought a gallon this past winter along with the applicator gun to apply to my recently purchased used 2011 Toyota Tundra. It is a lanolin based product that is applied to the underside of the vehicle. It can also be sprayed into doors. It remains wet for the most part but even if it gets wiped off, a waxy film remains. It used used a lot in Canada and northeast states. I will reapply at least once a year. My first thorough application this past winter required a little over 1/2 gallon.

Long term, the old school rubberized undercoatings can trap moisture which is why I researched the issue and found that Fluid Film is highly regarded by most everyone who uses it. A quick google search will tell the story.

[Embraer]

Waxoyl

[Aerkuld]

Originally Posted by Embraer

Waxoyl

^^ This was what we used to use in the UK on the old Mini. It can be sprayed from a long tube which you can fit into all those moisture traps. Seemed to work pretty well.

[Bobby77]

Agreed. The Cosmoline Sprays are ideal. We just got their newest spray....RP-342 "Heavy" (military-grade Cosmoline version)......best aerosol solution, hands down.

[Hugh R]

No expert here, but as I understand it, the salt only corrodes when its in a wet (not ice) environment. So frequent power washings go a long way to avoid the rust thing. The salt and, while frozen stuff, doesn't affect it too much.

[T77911S]

pull bumpers off and taillights and hose all the sand and dirt out from the areas where it gets stuck and moisture can remain.
also hose down the inner fender wells really good.

other than that you need to do the above, remove any lose undercoating and apply wurths.
you don't want to seal in any moisture or dirt.

[id10t]

The 356 talk list swears by POR15 for new/replacement undercoating. Maybe a spray on thick finish like rhino liner (truck bed liner) ?

Cosmolene will wash off if you are power washing with warm/hot water...

[pavulon]

maybe consider buying a reliable sacrificial appliance.

[RANDY P]

Originally Posted by Embraer

Waxoyl

Redneck waxoyl:

Diesel, ATF and wax

https://discoweb.org/forums/showthread.php?t=26892

[Bob Kontak]

Originally Posted by RANDY P

Redneck waxoyl:

Diesel, ATF and wax

https://discoweb.org/forums/showthread.php?t=26892

I like it.

If speeder only wants to do the underside a homemade schutz gun should do the trick.

[Tim Hancock]

Originally Posted by RANDY P

Redneck waxoyl:

Diesel, ATF and wax

https://discoweb.org/forums/showthread.php?t=26892

I tried this first and hated it. The melted wax would start to solidify in my squirt bottle as it cooled. I also tried it using an old siphon cup paint gun and the wax would solidify in the tip as it cooled from the air passing through it. After searching online some more I said screw it and just went with the proven Fluid Film and their modified undercoat gun.

[RANDY P]

Originally Posted by Bob Kontak

I like it.

If speeder only wants to do the underside a homemade schutz gun should do the trick.

Originally Posted by Tim Hancock

I tried this first and hated it. The melted wax would start to solidify in my squirt bottle as it cooled. I also tried it using an old siphon cup paint gun and the wax would solidify in the tip as it cooled from the air passing through it. After searching online some more I said screw it and just went with the proven Fluid Film and their modified undercoat gun.

I was thinking a giant paint brush myself....slap a bit in the wheel wells and in the arches and hidden nooks and crannies.

rjp

[scottmandue]

Originally Posted by id10t

Maybe a spray on thick finish like rhino liner (truck bed liner) ?

Being a native Cali boy I know nothing about undercoating, but I have seen 4x4 guys spray their whole truck with bed liner.