Rubberized Rust Proofing Vs Oil Based
 

just want to know which would be better as my brz is a daily driver and winter is fast approaching pros/ cons for each would be nice or the best overall

thanks!

A rubberized coating should be permanent while an oil-based coating will wear off the more you drive/wash. Rubberized coatings can chip off, so they can need to be touched up.

I just opted to use Fluid Film on all the bolts, suspension, and driveline components on my BRZ in order to save a few bucks over a professional undercoating. It cures as a wax-like substance that will prevent water from coming in contact with the parts it covers. From the reviews I was reading, it sounds like it needs to be applied yearly as it will wear off. Be careful not to get any spray on your brake rotors if you go this route. Any film that gets on the exhaust will burn off the first time you run the car, but you should try to avoid it anyways.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

We use Fluid Film on equipment that we leave out side for long periods of time. It is lanolin based and is sort of self healing. It can be cleaned of when needed.
It is available in one gallon cans that that can be sprayed as an undercoat.

The undercoating from the factory on the unibody is pretty tough stuff. You could also look into underpanels for the areas they cover.

As mentioned above, drive components, suspension, and the rear subframe in particular are really the only parts you need to worry about. I had a rear subframe rust out on an otherwise good Subaru.

I had some sort of oil based undercoating on a previous car. It gets really nasty and grimey over time. Not pleasant to try to do any work on anything coated with it, which was pretty much everything...

cool thanks i guess i will just put the car up on the hoist and spray down the main parts as mentioned above

Thanks!!

let it rust and just drive the car. by the time its really rusted, you will be done with the car or it will be the perfect time to upgrade that part.

I been using Fluid Film NAS for years on all my cars driven in winter.
Ziebart and coatings like that are crap.

Hi everyone, noobish question, but did all model years of the FRS come with factory undercoating?

Another vote for fluid film. When I lived up north (MA), we would coat our vehicles yearly before winter and there wasn't a spot of rust on them. It's an achievement if you know how much salt is on the roads up there.

@Tcoat , what is your take on the necessity of undercoating a FR-S/BRZ that is driven in Canada ... ??

No, this is not a trick question ......:D


humfrz

I understanding they are rust protected ..... but, I don't know if it is considered "undercoating".


humfrz

If we were talking about a 1964 Mustang or a 1980 Chevette I would say it is mandatory.
We are not talking about cars from the rust bucket eras though.
Over the last 15 years or so the manufacturers have gone to great lengths to produce cars that are far more rust resistant than the older ones. The need for rust protection on body panels went away a while ago even if the dealers would still like to sell it to you.
Are there parts that will still rust? Most certainly. Bolts, nuts, fittings, engine components and any other untreated steel or iron part will indeed rust. It may make a fastener slightly more difficult to remove or an engine component look bad but unless you are planning on keeping the car for 40 years none of this rust will actually damage anything.
We are 5 years into the car's life and there has not been a single report of any serious body rust issues. What we have seen is some slight bubbling around the window on some early 13s and a light tin strip (not a part of the body) holding a gasket in the front of the hood that got pretty bad. In comparison my mother had a 64 1/2 Mustang in 69 that was missing the whole rear floor and the wheel well archs were rotted about a good 3"s. In 1991 I had to scrap my beater 1984 Citation because the back door rusted out and flew off on the highway it had zero floor left in the hatch anyway.
My car is pretty much a worst case scenario as far as exposure goes. Not only do we salt the roads we use beat juice to make the salt stick. What makes it stick to the road also makes it stick to your car. I have a bad stone ship that actually cut the steel of my fender that happened two weeks after I got the car in 2014. In the name of science I have left it exposed through 3 winters and many, many, MANY slat accumulations. It has just recently started to develop surface rust and is probably many years away from rust through. The rest of the car (with the exception of the untreated parts mentioned above) is pristine. I would not even remotely consider undercoating on these cars. If somebody is truly concerned about the untreated parts there are several solutions as already discussed.


Spot (the picture makes it look worse than it really is)

tcoat thank you kindly for your insights to the factory rust resistance. It's greatly appreciated having feedback from a fellow Canadian!

I do need to add a disclaimer to my pervious post!
Ignore everything I said if you own. or are considering buying a Mazda.
They alone do not seem to have figured out how to prevent rust and the car will all but disappear in under 10 years.

Anecdotal but my boss had a 2007 Mazda 3 and had to get rid of it due to severe rust last year.

My car is a summer track rat and is daily driven each winter too. I have not done any rust proofing so far. I work on my car regularly and inspect in detail frequently. My personal notes about rust build-up are as follows:

The body panels, wheel arches and underbody are pristine.

As T-coat explained, nuts and bolts are corroded and will probably need periodic replacement as they go bad. I've already twisted one bolt head off when installing my BBK last year. Separate to this, entire exhaust is also covered in corrosion and will rust through eventually although that may take a while. It's a good excuse to upgrade to a proper stainless steel aftermarket exhaust anyway. The hub centers and the knuckles are also completely covered in surface corrosion but I expect it will take a very long time for them to start to have integrity issues. All of these are pretty expected and relatively minor issues to address.

Less expected areas, the pinch welds have a bit of surface corrosion because that is where my car sits when on jack stands and it's also where the car contacts when I go over a speed bump and scrape. I highly recommend cleaning them up and hitting them with some rust inhibitor if either of these situations are common for you. If not, then nothing to worry about here but definitely not something I'd be comfortable leaving alone if rust starts to develop.

Finally, the subframes have some surface rust as well near the wheel arches. I suspect these will be the primary concern for rust long term but at the current rate, I'd expect them to be fine for at least 15 years. I wouldn't call it easy but it's a bolt in job so not the end of the world to replace if they do go bad on you.

Edit: Forgot that I wanted to make a note about my aftermarket parts too. The coilovers have a bit of corrosion build up on the threads and collars but it cleans off with some rust remover and elbow grease. My BBK is mostly clean but the bleeders on the calipers got built up pretty well too but same story, nothing a bit of rust remover didn't fix. The part of the rotors that the pads don't contact has full surface rust but I'm just leaving it alone, the rotors will be replaced every few years anyways, well before the rust becomes a problem.