Fluid Film coating: how to spray?

[Elkins45]

I drove my new-to-me RAV4 in the snow this week because that's why I bought it, but it gave me pains doing it. It's apparently spent its life in a garage because even though it's a 2012 the undercarriage looks factory new. I want to make it last as long as possible so after the road set is gone and it warms up I want to hose it off and give it a coat of Fluid Film. FF comes in aerosol cans and also liquid in a bucket. 44 ounces in spray cans costs the same as a gallon of liquid so that's obviously the better bargain, assuming I can apply it. Would it be possible to spray it using a squeeze pump squirt bottle or is it too thick? How about a pressurized garden sprayer? Or should I spend the money for a spray gun that attaches to my air compressor?

 

[Rand]

It's a really dirty job. I pay someone and Skip the mess.

 

[Lubener]

I have found that Amzoil makes a better product than Fluid Film. I use an aerosol can which is quite powerful and better than a squeeze trigger bottle. Three cans will do a full size pickup. Fluid film doesn't really dry well but the amzoil metal protector dries to a parafin based coating. I do mine every two years. A day or two before applying, I go to a self serve car wash and do a complete underbody rinse. Doesn't make sense to spray on top of dirt and grit. Either one, use a mask, go under and start coating. It is messy and drips, so you don't want to apply over your nice cement driveway.

 

[brandon9715]

I prefer Wool Wax to Fluid Film, but I have used both. They are thick enough that if you buy the gallon pails you will need a spray gun to hook to your air compressor.

 

[jsean]

I’d be careful applying it now if the RAV4 has already been in salt and slush. If you do apply it this season, I’d highly recommend hosing the under carriage on your driveway, let it dry up and then coat it.
I’ve been experimenting different setups for the past few years. Surface shield as the general coat and FF in cavities and rocker panels has been the best thus far. Next year, I plan on trying wool wax instead of surface shield and keeping the FF for rockers/cavities.
I do the cans because I’ve found them to be convenient crawling underneath the cars and getting them coated.

 

[slybunda]

I went with noxudol 700 in cavities and sprayed under the car. Can't be dealing with fluid film which just lasts a year and has to be done again

 

[Tdbo]

It's a really dirty job. I pay someone and Skip the mess.

This, plus my Krown guy has the tools to do i thoroughly, so it gets in as many of the cracks/crevices as possible.

 

[Donald]

You might consider getting it on ramps and spraying a salt-away type of product and letting it dry completely.

CarWell can be sprayed with a $3.00 trigger sprayer from Home Depot. But you need something to spray up into cavities that is pressurized.

I suggest going to a shop and having them do it the first time. Then maintain it yourself in future years. You probably don't have to do spray into a lot of cavities each year. Once or every few years should be enough.

There is NH Coatings, CarWell, FluidFilm, and others. Hopefully you can find a shop that does it not too far away. Since it's not a new car you want a oil based product not a wax.

 

[B1974]

I've used the FF aerosol cans and now use the less expensive one gallon can and spray it with a cheap under coating spray gun. You can pick up a spray gun on Amazon for about $20. This stuff is so thick in the gallon version that you need to thin it a bit with vegetable oil as per FF websites recommendations. I keep using aerosol cans for the door drip holes and other tight spots that I get into with a 2 foot long spray can straw extensions that are also for sale on Amazon.

This is the undercoating gun I have.
https://www.canadiantire.ca/en/pdp/...g-gun-0475761p.html?rq=undercoating+spray+gun
These are the straw extensions for the aerosol cans.
https://www.amazon.ca/dp/B0DQTLNBDL...80735df54&sp_csd=d2lkZ2V0TmFtZT1zcF9kZXRhaWwy

 

[The_Jeff]

The Blaster Surface Shield I used this year seemed thinner (and easier to apply) than the FF buckets I've used in years past.

I use an undercoating gun like this one. Note the 2-inch mouth on top of the jar-- one needs to funnel the product into the vessel which is a very messy process.

I would compromise this year and buy a few aerosol spray bombs and hit the most critical parts, then do a full-on bang-up job next fall with the right equipment. As others wrote, wash and dry it thoroughly underneath. Warm water dissolves salt way better than cold. When I lived in an apartment I hooked my hose to the hot water spigot for my washing machine and threw it out the window, LOL.

Warm the spray bombs up in a bucket of hot water; they flow better and you get more out of the can.

BTW congrats on finding a 4wd in such excellent condition.

 

[Fordiesel69]

Use woolwax or blaster sheild.

Buy a cheap spray gun at HF and use a compressor.

Heat the product to the point it is uncomfortable to handle.

 

[supton]

I elected to buy the FF gun and go full tilt on it--I figured, if I used it for years, then it'd pay for itself. Still have a bucket of FF in the garage as I would apply every fall and would try to do touchups during the winter. Which is why I stopped as it just doesn't stick. But it's relatively easy to apply. Just have to somehow get it up high enough that I could crawl up underneath, wearing a paper suit, goggles, and if I was smart, a respirator.

I need to get underneath and look at what I sprayed with RP342 last year (?). Last time I was underneath it seemed not to be working.

 

[The_Jeff]

The respirator is a must-have. Only 20 bucks for a half-face at Home Depot.

 

[KrisZ]

Invest in a shutz gun and a small compressor as you will need to repeat the job annually for the first few years until you build up some layers.
I would also try and find a better product, FF is mediocre for the task. Try finding Corrosion Free, I found it superior to FF and Krown. It's pricey at $74/Gal, but you will likely only need half a gallon per treatment. Even less after the initial treatment, which uses the most amount of product.


https://corrosionfree.com/store/rust-cure-formula-3000-jug/

 

[AdmiralYoda]

I vote Noxudol as it comes in an aerosol can and you can attach a "wand" thingy to help get it into cavities. Noxudol is a waxy rust preventative that will actively fight rust and convert it to an inert material. Noxudol 700 goes in cavities as it is a bit thinner and Noxudol 300 is the undercoating. Dries to a hard waxy coating, not a sticky goopy mess.

They both go on thin and tend to wick into tight nooks and crannies, then dry hard over a week or so.

 

[iahawk]

these are all great suggestions on how to do it the best way. If you're lazy like me you just put each end of the car up on ramps and spray about 3 cans of FF on everything underneath that looks like it could rust, avoiding rubber components (per FF directions).

 

[Kestas]

I've rustproofed many cars on my driveway. The product should be cut with mineral spirits and sprayed on to the car. The mineral spirits flash off in a few days.

 

[slacktide_bitog]

You can spray it like you mention, or you could even use a paint brush and brush it on

 

[Fordiesel69]

Woolwax or Blaster Sheild is better than fluid film. I used fluid film for years and it washes off in high splash areas.

Blaster Sheild is so far superior, but I have not found a reliable source for 5 gal.

 

[GW.]

I used Fluid Film for years with great results. But have been now using Surface Shield for the last 3 years. Surface Shield lasts longer. I find the spray cans easy to use. Harbor Freight sells them for around $10 each.