3MProfessional Grade Rubberized Undercoating, Corrosion, Water and Salt Spray Resistant, 03584, 16 oz. Aerosol

Great stuff!used for my fender wells , and I’m impressed! WEAR A MASK WHEN USING . THIS STUFF IS STRONG!

I used this on my running boards. Parts of my running boards were wore down to metal. I applied the rubberized undercoating to my running boards after first cleaning and drying them. I did three coats (I could have stopped at 2), allowing the undercoating to dry between coats. It came out amazingly well and even better than the original. I highly recommend this awesome stuff!

I believe this to be a quality product, as all 3M products are always top notch. I did the majority of a full-size three-quarter ton crew cab pick up. The truck was 11 years old and spends its time in rough Michigan winters. The chassis was starting to show signs of rust and the original frame coating was definitely wearing off and rust coming through. I spent minimal time just peeling the loose flakes off. I used a file and wire brush to clean up the trailer hitch. The final finish is nice that it hides some minor blemishes to give a neat finished appearance. My rusty hitch now looks very good. Application and positioning of the can so it could apply did not matter. I was able to hold it at various angles and it works just fine. I used 10 cans and ordered 10 more to finish a few more spots and maybe do more of my other vehicles. I spent a lot of time researching and looking at reviews of things such as POR 15. My only regret is I did not apply this product sooner. I did the application without protecting my arms or face and I did regret it after I climbed out from under the truck. I had to go to work soon and look like a mess! I was amazed that when I sprayed WD 40 on a rag, it cleaned me up as if it never happened!!!! As I have always believed, 3M products always live up to a high standard. I would purchase again, I did purchase again, and I will purchase again!!!

Overall i like this product alot. It wasn't difficult to use, it works well for its designed purpose and is not that expensive. Definitely cheaper than having an undercoat done. I used it on my Jeep Cherokee on the door bottoms to prevent rust that had just started on it that is typical for Cherokees, as well as the fender flares and part of my hatch i did a design on to prevent rust below the window but a black strip would look odd (for reference a 1/16 inch thick coat took 5 cans). What this product is basically is an aerosolized, hardening, tar (meaning like road tar/asphalt). The advantage of this is that it is nearly impossible for it to chip so once applied water will never get in between the coating and rust out the steel. A disadvantage of this compared to say Rhino Liner (a ultra tough hard plastic like coating which I am aware isn't considered an undercoating) is that with enough force a jagged object can scrape it off. However refinish of a scraped off area or scratch line would be a very easy repair with simply another spraying or spraying some in a cup and dabbing it on. So when you purchase this think of it as a midpoint between Rhino Liner and Plasti-Dip (a latex like coating that can be applied and easily peeled off). As far as aesthetics go I really like the look of it, if you spray closer it smoothes out more to a molded plastic like look or if you spray further away from your surface it looks more like a powder coat/bedcoat. However if scraped it exposes that it's not truly black but a very dark brown. Also before spraying on the surface of your project I recommend practicing on a piece of plastic or cardboard, once you get it down its not difficult to apply however if you go to slow you'll get blobs that will not dry properly and look bad. As far as drying time goes between each coat it needs at least a half hour to tack on, then after a few hours it will seem hard to the touch but it's not. At this point it can be touched with your fingers and nothing will happen but if you use your nail some may scrape off. Only after 2-5 days depending on temperature, humidity, and air movement will it achieve its full hardness. That's as much as I can learn anyone about this. Hopefully this helps future buyers of this well made product.

The can itself sprays just like you think it should for a product like this. Heavy coverage on one coat, even from an extended distance. Great product.

Goes on easy, nice coverage, very adhesive to surface-look great!

is what we expected. No complaints

Sprays on easy. Smell is kinda strong so allow for ventilation. Spray is a tight pattern but minimal masking required if your careful.