B’Laster Surface Shield Anti Rust for Metal – Rust Prevention for Tools, Equipment & Moving Parts – Long-Lasting Corrosion Protection with Lanolin-Based Formula – 1 Gallon

I found this easy to apply... I initially used a brush to make sure I got into the crevices and hard angles... before going back over it with the undercoating gun. The frame on my F150 was largely rusting from the inside out... the outside looked pretty good, but the inside was a scattershot with deep corrosion (see pics).... so I replaced a lot of that metal and wanted to get a good coat of this stuff inside the frame. I used the 360 attachment with the flexible hose on the sprayer and had absolutely no problems getting all the parts inside the frame since this stuff sprays pretty easily (probably a 70 degree day). I had the truck bed off and had this sit in the hot sun for almost a month before I got everything back together. It became a more durable waxy film in that time and I resprayed everything again when I reassembled it. I didn't have much overspray and didn't waste much, I don't think I used much more than 1/2 gallon for this treatment. One of my concerns with this product is that it might be flammable if subjected to very high heat. Before trying it on the truck, I had sprayed some on test metal and hit it with a propane torch to check how sensitive it was to heat. That test turned out really good where this stuff smoked/steamed but never flared. It seemed to leave a waxy residue that continued to shed water when it rained over the next few days. It worked so well that I hit another vehicle that I was having rust issues with... but accidentally got some on some areas that I had yet to repair inside the frame. So, I cautiously welded on the area and observed good amounts of smoke/steam billow and watched as it liquefied and dripped down the frame rail... but no flaring. It seemed to pass that test quite well, too.

DIY install on my full size truck and a Subaru Outback… 5 gal purchase… provides superb protection from snow and salt brine used on the winter roads here locally… Applies without fault when used as instructed with proper application tool and air compressor at 60 psi… Wear protective garment and PPE as it is a messy job. Not inexpensive via 5 gallon purchase but cost effective. I do highly recommend this brand.

Bought a gallon of this in 2024, and applied about 1/2 of a gallon to the underside of my Chevy Silverado. Used a woolwax spray gun to undercoat, and the flex extension to do inside the frame as well. Made the mistake of waiting until late November, so it was very cold, but still worked, it just took longer and needed more air pressure.. Didn’t get to apply it in 2025, and bought the 5 gallon this year to do family cars. Redid my truck today 8/16/2025, used about 1/2 gallon again. This time it went on much easier as it was a warm day. I probably put it on thicker than i needed too. I was happy to see the 2024 coat was still mostly there, only missing off the bottom and sides of the frame and places that get a lot of road spray. This stuff seems to never fully dry, and hold its place really well. I only got drips in places I sprayed way to much on. I would recommend coating once a year for the first couple of years, and then you could probably go every other year unless you get undercarriage washes often. I would also just get the regular natural color as it goes on mostly clear, as overspray IS going to happen and the black version may stain your garage floor or driveway. Also it doesn't have a strong smell like some other brands, so you dont end up stinking so much.

Previously used another brand treatment WW. I got the kit that came with their gun which I have now used to apply this. My main issue with the other stuff was how thick it was to the point where it was not very usable below 40° out of their own tool without warming it up as I went. This stuff sprayed incredibly well comparably. This stuff seems to last longer as well as I have applied it from a can previously. This is definitely the way to go with a compressed air gun, so much easier to apply. This will be my go-to product from now on. I sprayed one body on frame 4x4 truck, getting inside all of the frame members and everywhere else, and also did one economy sedan. Ended up using about 1/2 of this tub. I probably put it on quite a bit heavier than needed, but why not go a bit over the top. As a bit more scent for about two weeks after, but it's nothing offputting to me. After putting it on a month ago I can't smell it anymore unless I climb under my truck.

This stuff went on great, and it really sticks extremely well to metal. It's a major pain to clean up, though, because it's so tacky. But to me, that just means it's going to stay on my frame for a very long time. Try to avoid getting the product on your hands, unless you want to wash them for an hour. Latex gloves are your friend. Also, using a tarp to avoid getting this stuff on your garage floor would be a great idea.

I'm convinced it's a great product; I used it on a camper that sits at the beach all summer in the salt air. The frame and underneath are rust free and show no signs of corrosion. I applied it with a cheap air gun I got a harbor freight which did the job. I first washed the underneath then after drying applied it to all surfaces underneath to include the support jacks. The coating is a moist finish but doesn't seem to have dirt stick to it from the wind, also a bonus hornets and ants are not a fan, so it helped with insects. I should of taking some photos. The one thing to remember is applying is some work using an air compressor and spray gun.

Very easy to apply with a small harbor freight inexpensive spray gun does not produce much over spray that required masking but does leave an oily feeling film that does not seem to dry which should not be a problem as long as it prevents corrosion and will not hold dust or dirt that could not be easily hosed off from underneath. Only took a little over a quart out of that gallon to treat under my Ford Maverick truck.

Works great. I have used it in fairly cool weather - bring it indoors so it gets nice and warm and it flows and sprays just fine. I use it in my Wool Wax gun. Friends and relatives are using it on their vehicles now. It seems that a gallon per vehicle is about right to do a thorough job. Exposed underside could use a touch-up in a year or two if you drive through a lot of rain. I also use it on my trailers. Unlike some similar products it does not leave a nasty lingering odor. Nice all around.

Did not use it yet, will undercoat my trucks soon, but from what is said about this product online, and my own experience with other products, I have no doubt this is the best product out there right now!! Yes, better than fluid film...

I wish there was larger quantity size available (5gallon). This product is thick, creeping, stays liquid (does not harden) and overall the best undercoating on the market along with fluid film, without the strong odour. Recommend spraying in warm/mild temperatures, in cold weather need higher PSI. Thick and lasts long. Solid choice, will buy again.

This product may be a bit pricey but, it offers superior protection against metal corrosion. Easy to apply,when using the proper spray gun. Very long lasting and doesn't wash off as easy as other products on the market. Used less than a gallon to do my entire truck. In my opinion it's the best product on the market today. Better then Fluid Film because of it's durability.

I have reviewed and watched video on You Tube on this product and I found the information and testing observations provided to be very interesting. The mere fact that it will withstand the water splash of rain or snow and still maintain its protection were convincing enough for me to try the product. From Canada, the only place I could find this is in Princess Auto only in a spray can which is not enough for a vehicle under spray. I ordered the 1-Gal Pail directly and arrived through Canada Post without any hassle or problem encountered. I scheduled our Toyota Sienna for an under spray with my mechanic. I watched the spraying being done, quite liberal on its application even within the inner holes of the vehicle frame and door panels. A 1 Gal pail is just right for a van with a few cups of the materials as excess. Not a drip was wasted nor falling on the floor. When I parked our vehicle in the designated garage parking area I did not see any dripping of the solution used. Will monitor the situation as time goes by. I ordered another gallon for my Honda Civic which I will also schedule for under spraying. I think it is worth the investment with the type of protection the Surface Shied will provide to you investment with your vehicle.

I got this instead of fluid film because it had a 2 year coverage claim. I found that it was no longer on parts of the car after one winter season up here in Canada. Same as fluid film. I think it would stay on in a climate that has less snow, but up here it just comes off. Could be salt content, could be slush, no idea. The product is much more runny than fluid film. This could be a pro or con depending on your application style For either product I am never able to get the coverage I want, my air gun sprays it on much too thick. I think I would like to try the black coloured variant next to help me see where the product has been used I would get this over fluid film if you are applying in cool weather and want to test our their claim themselves. if they have a money back warranty it might be worth documenting your application and following up in two years.