Automotive Spray-On Rubberized Undercoating Material, 1-Gallon RUS-1020F1

Undercoating is great with very thick and stable coating properties. Easy to spray multiple coats and fast drying. However, make sure you purchase disposable sprayer since this stuff is like a spray-bomb. Overspray go's everywhere; on vehicle, you, dogs, cats, ground, house, and down the driveway. Make sure you are 100% covered with disposable clothing, gloves, goggles, head covering, face shield, etc.; you will absolutely be covered in black tar-like substance that is only removable with solvent. Best to just throw away everything involved in spray process. Do not get any of this stuff on exhaust, mufflers, or any other vehicle components that get hot; will produce nasty vapors for months after job. Also, coating is heavy so stay away from vehicle rotational components unless you like vibrations from out of balance driveshafts. Do not make mistake of thinking you can spray coating in any precision manner; cover, mask, and tape areas not to be coated. Procure sprayer with extended nozzle (say 5" or so), this will allow coverage of hard to access areas, and insertion through undercarriage access holes and inner frame areas. Place large cardboard sheet over driveway unless you want large, permanent, sticky black spot.

Don't get just one gallon for your car, I put over 2gallons onto a Ford Focus and came out great. Be sure to get 2 or 3gallons for a NEW car with 4 doors. I thinned it down some (mineral spirits) and used my own homemade hose-spray head. Made my spray tube using some 3/8"ID vinyl tube that I heated end and melted it flat-closed. Then heated a small nail to poke/melt holes into the flattened end at different angles (Pattern like a "5" on a dice" on both sides with some poked into the flattened ends too. it made fine mists and directional into the corners of frame. Be sure to buy some Tyvek jump suits with head coverings; cheap latex gloves, plastic sheeting to cover over & under the car. Also tape up the seams from hood & fenders so spray does not get onto finish. Pull inner fender liners and bumpers to do it right and get car up as high as possible. I used a gun that was "bought with" this stuff and worked well with mods. However the 3M spray tube (bought with) was worthless as it was way too stiff, kept kinking and causing air to blow material out gun breather hole all over me/car. Lastly use full face shield with tear off liner/shield so you can see when overspray gets on you.

I've used RusFre undercoating for two decades. It makes a mess, never comes out of clothing, and takes some scrubbing to get it off yourself, but it works great. I run tractor trailers in the northeast, so they're swimming in road salt and corrosive de-icer six months of the year. Rust jacking (rust build up between parts) is a real problem, and can break parts if allowed to fester. I coat the mating surfaces with RusFre any time I replace a part. It eliminates rust jacking virtually 100%, and in the rare cases where it doesn't completely stop it, it slows the process tremendously. It stays on surfaces permanently. A factory-applied frame paint on a truck I bought new was mostly reduced to rust and rot after less than six years. I sandblasted everything, coated all the parts individually with a high quality rust preventative paint, then coated everything again with RusFre. It went through five New England winters after that, with zero visible rust.

This is some pretty good stuff. It creeps into the crevices and covers extremely well. It dries nice and black with a semi gloss finish. I got a really nice uniform texture using a 3M Schutz gun at 60 psi. The only reason I knocked a star off is for excessive dry time. It took 4 full days in 80 degree weather with a fan on it before it wasn't tacky anymore. If you can cope with the dry time, this is what you want.

It is great I should have got 2 gallons you can’t find a better deal then this

I used this on a 1975 el camino I'm restoring. I saw that it has rust inhibitors (for those of us in the "rust belt" require all the help we can get) and it also had fibers in it to help bind the material as one. and it was way better priced than my initial plan. This stuff is sticky and if you plan on spraying it while your under the car take proper precautions, mask, goggles or facemask, gloves, and a painter suit. it gets everywhere when spraying it. and the disposable suit makes clean up way easier. Spraying it you get identical results as what the factory undercoating looks like. I went through 2 and a half gallons for the whole underside. and that's hitting every corner I could. might be a slight but overkill but I figure for the cost of this compared to others its worth it. For clean up I used mineral spirits and that seemed to work well with cleaning the gun and the air hose where it got on. I already recommended it to a friend of mine for his car.