Undercoating - Blaster Surface Shield - Quick Guide

Here's a quick rundown of some Surface Shield rust-preventative post-application thoughts:
This Youtuber - Repair Geek, does a great job on his channel, and he is the reason that I chose Surface Shield. The important thing with rust prevention is not using products that trap moisture or rust and exacerbate the issue.

• 1 YEAR UPDATE: I originally did this in December 2023, and now (Dec 2024), I can say my frame looks almost perfect; the Surface Shield has turned into a nearly dry waxy substance because it's collected enough dust and dirt. There are only a few spots where it's 'faded' from heat or from constant water spray, though not completely gone. I can also see areas where I did not spray that it crept.
  
• New Advice: Keep a can nearby anytime you work on your truck in the future because you'll find places you missed.
• Not a stinky mess: Surface Shield truly did not have a strong scent, in my opinion. My clothes washed easily, and I laid out a tarp, preparing for drips and mess, but there really wasn't much mess. Even over spraying certain sections, there was only slight dripping.
• Frame interior nozzle: I bought this cavity wand here, BS Coatings 75015 36" Cavity Wand with 360-degree Spray Tip. I made one dumb mistake: You need to make sure the Surface Shield cans you buy are compatible with the cavity wand you buy regarding male-to-female connections.
  
• Bad aerosol reviews? Heat the cans in a bowl of water and shake often. If a can cools down while being used, swap cans. This makes an enormous difference and solves almost all the problems in the negative reviews.
• Spraying Indoors/Outdoors: Because there wasn't much mess or scent,, I honestly think you could use SS indoors. Plus, you could easily light up the underside of the truck. If you do it outdoors, pick a cool and less windy day.
• Damaging rubber: B'Laster says SS is safe on rubbers/plastics, and the internet seems to agree. It's my first coating, so I don't know, but I didn't try to seriously avoid anything. Naturally, I wasn't trying to waste product, so I was aiming just for metal.
• Paint/Rust Reform: Ideally, I would've had the time to go through with a fine-tooth comb and paint over any rusty patches, but I didn't have time this year. Maybe next year, I'll knock this coating off and redo it with more time and make sure to take care of the rust. That's a benefit of a "removable product."
• Tricky/Missed Spots: There are a few parts with very tight gaps, which I found around the gas tank tricky. But between spray straws and the 360 nozzle, it seemed easy enough to get most everywhere. I haven't hit inside the doors or fender wells or anything like that yet, but I'll be exploring that, maybe getting to it this winter or next year. Update Dec 2024: I did this during the summer while working on something else and I also finished this fall. Lift-gate drain holes. Passenger Door drain holes. Under Kick panels. But I didn't spray too much to clog those from drainability.
• Visibility: I did mine close to sunset, so it was difficult to see lying under the truck looking in that direction. Now that it's not a stinkin' mess, I'll opt for indoors and use a bunch of shop lights for better visibility.
  
• Need a Lift or Not? I did my surface coat with a tire rotation, so I put the whole truck on jack stands and removed all wheels. Maximum visibility and freedom for movement. If I had access to a post-lift, that would've been a dream. You definitely should drop the spare tire.
• How many cans? I think I used 5 aerosol cans, and I wasn't very careful. I oversprayed at times, ran a long time inside the frame, etc.
• Time: It probably took about 3ish hours to move safely and slowly to lift it up, remove the tires, look for every corner I missed, etc. Update: Touching up throughout the year took 5 minutes at a time.

I intend to drive this 4Runner as long as possible and for a 10-year-old truck in the Midwest, it's got a clean frame, so this treatment now makes me sleep all the better.

 

Nice write-up, thanks!

 

Definitely looks better, and you're right it didnt look that bad to begin with honestly. How did you get inside the frame rails?

 

The frame interior nozzle part is the answer to this!

 

hopefully it helps!

 

Update advice: keep a can or two laying around and get it warmed up every time you plan to wrench! Seriously. Between oil changes, doing my diy rear diff breather, etc. I continue to find spots that I missed. Originally I had not done anything inside body panels either. Since then, I’ve now removed kick panels inside the door and added some and I added a light bit inside the doors at the lower drain holes too. Not too much but enough hopefully to avoid rust in the corners. Still haven’t done inside the fender wells technically, but I’m sure I’ll get around to that eventually.

 

Bump in case it helps anyone this time of year!

 

I just purchased 3 cans, looks like I might need a few more. Thanks for the write up.

 

You're welcome. I hope it helps. You can get by with 3, but 4-6 is probably ideal, especially to keep that extra can lying around for every time you look under the truck.

 

So, after application, is this stuff a mess to touch? I guess what I'm asking is if I'm doing something underneath am I going to end up a mess afterward?

 

Basically, it will stay "slimy" until it collects enough dust to become "dry but tacky." If you click this YouTube link, it will start when he starts wiping away the coating that has been applied for some time. YOUTUBE LINK. You can clearly see the texture in this video! And look at that beautiful frame + hardware under the tacky

 

You will only end up with it on you if you touch it.

 

The transparent shiny layer will disappear and become a matt black layer due to dirt.
My 4Runner has fluid film on it for a year now. Last weekend i just bled the brakes, in a old clean sweater.
Yes, always wear old and long clothes under your 4Runner.
And never get the idea of just doing something quickly without changing your clothes.

 

Yes, which is why you want to use Cosmoline 342 black. It gets hard like candle wax.

 

Yes, I always forget to change clothes before starting work haha. Whoops.
Also, we should start a separate thread for the undercoat product debate, this was really just intended to be a brief instructional post for those interested.

 

Thanks for the feedback. I'm not in a heavy snow area so it's not something that I HAVE to have (we have years with not a bit of snow). I was thinking about doing it for a little extra protection for wheeling. I think the messiness after application might make my OCD shut my brain down.

 

Well, driving down a dusty road after you spray on a lighter coat will pretty much solve any "messy" problems. I recommend watching the YouTube link that I shared above. However, I'll additionally say that you could also just coat the inside of your frame (I shared how in the original post) for longevity's sake + peace of mind, and you'd never have to see it! Possibly a win-win for your OCD mind.

 

Good call on just coating inside....

 

A few years ago I drove down to New Orleans, I have never seen any of my vehicles with so much “salt” or “road chemicals” covering it in my life, and I’ve lived all around Maine. Think about any freezing rain or any treatment they may put on the roads down that way. Or any planned or unplanned travel you may end up doing in the winter months. Oh, and my sliders started to show signs of rust after that trip. Which would be worse for your OCD, rust spots or a treated frame. I’ve used Fluid Film, Woolwax and surface shield, surface shield in my opinion is the cleanest of the 3, and probably the best.

 

I think cosmoline would have been my second choice if I hadn’t done Woolwax, for that reason.

That said, my woolwax has set up much like an actual wax coating once it got saturated with dust/dirt. The other benefit with woolwax is that it doesn’t have solvents, and isn’t really toxic. Same with fluid film. They both have a bit of a “barnyard” smell, woolwax less so. But neither have the solvents that would require using a respirator. Maybe a simple mask if you are spraying, and you don’t want to inhale suspended lanolin particles.

I’ve also tried out a can of surface shield for touch ups. It’s not a horrible smell, but it’s definitely wafts of petroleum distillates. If I were doing a whole vehicle, I’d rather do it oustide, with a respirator.

 

I hope everyone will get involved on the new thread: https://www.4runners.com/threads/ultimate-undercoating-argument-thread.42242/

 

The Cosmoline black has a slight coconut oil smell. I was shocked at how little odor there was in my garage afterwords-very faint and not off putting at all. Even the overspray on the exhaust didn't smell bad and burnt off in the first short trip I took.

 

That’s surprising! I figured it would make the 4runner smell like old military surplus rifles lol.

 

Just got 2 cans of Blaster and 2 of Fluid Film. Figured i would use Blaster in already slightly rusted spots and Fluid Film for other spots/holes.

 

anything is worlds better than nothing!

 

Just an FYI for the people that do undercoat their 4Runners with either fluid film or surface shield, etc. - you might want to let your dealership know ahead of time when going in for an oil change or anything that involves them getting under the vehicle. (I know, sounds crazy)

I undercoated my car with fluid film and took it in for my 5,000 mile oil change and after waiting for 3 hours I politely asked what was taking so long. The service manager pulled me aside and said that they found a small issue and wanted to show me some pictures and that I would need to bring my 4Runner back in for some additional work. They then showed me pictures of the underside of my 4runner claiming that there was an oil leak and the tech was trying to track it down while also cleaning the frame to do so. I explained that it was fluid film and not an oil leak, and the tech seemed relieved stating “I was going to say, this thing is brand new it shouldn’t have an oil leak.”

A little concerning considering my entire underside was sprayed with fluid film even inside hard to reach places that an oil leak wouldn’t necessarily reach. Might look into doing my own oil changes from now on haha.

 

lol that is funny. Speaking of which, I also did tell them the frame was " messy " but I think up here in North they see it so much that they already know what is it.

I have woolwax on my Tacoma , its been over an year and its still there

 

You would think in Colorado they would also have some experience with undercoatings. And Fluid film definitely looks different than oil.

 

Well it does smell like petrol and is thicker but someone who has never heard of it, prob thought it was oil. The wool wax I have is pretty thick, maybe like 30 sheets of paper or more, but its black so its not easy to see

 

I think fluid film has a unique smell as well, but I have been dealing with it for a bunch of years nor.