Lost cost, spray-on rust prevention

[1975]

For those that apply your own low cost undercoating/rust prevention spray, what do you use and how often do you use it? How has it worked out for you?

Just picked up a new Mazda CX-5 and cost-wise, I'm looking at Fluid Film from Amazon or Rust-Oleum Pro Grade Undercoating from Walmart. I was about to go with Fluid Film but then saw some reviews that said it actually attracts and holds dirt. I plan to run the car through a touchless car wash about once a week.

Thanks

 

[2010Civic]

I spray my cars with fluid film every fall. Yes, it attracts dirt but that fluid film/dirt will build up after a few years to become a solid layer of protection.

 

[doublebase]

I’ve either used fluid film or NH oil undercoating in the last. Both seem to work well. Sometimes I’ll apply it twice a year, sometimes just once. I wouldn’t worry about dust/dirt being attracted to the coatings, it’s what supposed to happen. It’s what you want - for it to set up into the fluid film and create a stronger barrier - a lot of rust prevention places will tell you to drive on a dusty/dirt road after application.

I’s be careful about the weekly touchless car washes, I probably wouldn’t spray the underside of the vehicle after it’s been treated (as tempting as that might be) because you’ll accelerate the washing away of the film.

 

[thastinger]

Road salt protection or general undercoat?

 

[Bob in Utah]

This stuff is similar to Fluid Film

$10 can at Hobo Freight

 

[Lubener]

This has worked well for me. Lasts two years.

Heavy-Duty Metal Protector

Shop Heavy-Duty Metal Protector at AMSOIL. Find premium synthetic oil, filters and more online. Fast, free shipping available.

www.amsoil.com

 

[1975]

Road salt protection or general undercoat?

Road salt.

 

[thastinger]

Road salt.

That seems to be a much more frequent application and mainly petroleum based. I think there are shops that specialize in that application but maybe some of the salt land folks will chime in as I don't have to worry about salt very much.

 

[KrisZ]

The cheapest oil rustproofing is oil based types. These will attract dirt and grime. There is no way to avoid this.
There are some wax based products that don’t attract as much dirt and are somewhat “dry”, but these are expensive.

 

[RooflessVW]

I use LPS 3. I blast the cars probably once a year.

 

[1975]

That seems to be a much more frequent application and mainly petroleum based. I think there are shops that specialize in that application but maybe some of the salt land folks will chime in as I don't have to worry about salt very much.

Yep, I'm starting to think I might just take it to a local shop. There is a place nearby that does it for under $200.00. It's a tough call though.

 

[Rand]

Yep, I'm starting to think I might just take it to a local shop. There is a place nearby that does it for under $200.00. It's a tough call though.

Dont bother washing it every week.. it may cause more rusting by removing the protection.

the 3 of the more well known are rustcheck, fluid film, and krown.

 

[PF52]

This stuff is similar to Fluid Film

$10 can at Hobo Freight

I am using that stuff on my new-to-me Honda Fit which is virtually rust-free (and I'm trying to keep it that way). Too soon yet for any results of course since I've only had it since November.

 

[thastinger]

Yep, I'm starting to think I might just take it to a local shop. There is a place nearby that does it for under $200.00. It's a tough call though.

That seems like a no brainer to do that for that amount of money. I'm sure that you would have 60-80 bucks in materials and you don't have a lift to get the vehicle up in the air so you can properly access all the nooks and crannies.

 

[slacktide_bitog]

Welcome to BITOG

Any of those are fine, as is Krown. All of them are supposed to be done annually.

If you can get it done at a shop for under $200, that is a great price.

 

[Fordiesel69]

My secret sauce for a good car:

1.) Krown for all internal cavities (this is the most important.) I simply look in parking lots for a rot bucket and wherever there is rust, find out how to get krown into those spots.
2.) Then woolwax for the entire underside chassis.
3.) Keep a can of PB Blaster sheild (from harbor freight) and respray the wheel arches lips, and the door and tailgate seams thru out the winter like every month.

For junk cars you just need to have last, slather it with bar and chain oil before and after winter.

**Never ever apply used motor oil** not only is it terrible for rubber parts, but you will be inhaling a ton of toxic fumes.

 

[Oillover]

Anyone experience problems with Fluid Film on rubber parts?

 

[Rand]

Anyone experience problems with Fluid Film on rubber parts?

Fluid film is lanolin should be minimal issues

you would likely have more issues with petrol based products such as krown.
if they get overzealous and blast it all over your engine bay you need to wipe it off the hood seal etc.
The hood seal on the ram is swelled enough to bunch up from krown.

it also affected the "foamy" type washer fluid line on the elantra allowing it to blow off the plastic inline connector(where 2 lines connect)
from the backpressure of spraying. a couple zip ties fixed it.
I will likely switch to rustcheck on the next vehicle due to this.. but krown is very good for protection.

 

[supton]

Yep, I'm starting to think I might just take it to a local shop. There is a place nearby that does it for under $200.00. It's a tough call though.

Not a bad idea if they do it well, but you might want to buy some yourself and do touchups over the winter.

Plus, I have to wonder, the stuff that gets into the nooks and crannies, is unlikely to wash away. Not saying one and done, but maybe every other year, with the years between being you getting underneath.

 

[JoelB]

Careful with getting a cheap undercoating job done for you. You won't know they did a bad job until you have rust holes years later.

People focus too heavily on surface rust under their cars when the main reason to undercoat is to coat internal cavities. A vast majority of cancerous rust come from the inside out.