Busy sound proofing my Gen 3 Prius five. I removed the driver side wheel well inner liner and I scrubbed it down with a mix of hot water and Simple Green de-greaser. I then scuffed up the FatMat with 80 grit sand paper To give the foil on the FatMat some teeth so the Spectrum Sludge sticks to it. I then placed a floor fan in front of the wheel well and hopefully I can put it back together tonight.
I ended up with 3 layers of sludge over the top of the FatMat. The drying time is about 1 and 1/2 hours until it is dry to the touch. The picture is just after the first coat of sludge and I used a 3 and 1/2 inch wide paint brush as an applicator. I still need to do the passenger side wheel well but I noticed a slight decrease in road noise after doing the driverside front wheel well. I barely used maybe a 4th of the gallon and I have 2 gallons so on a day off I will get the other wheel wells done and the concentrate on the underside of the car under the front seats and under the rear hatch. I also have some MLV and I would like to do the floor under the front footwells and possibly even remove the front seats too but I will see what the less invasive products accomplish before tearing my interior apart.
It has the consistency of thin peanut butter and no need to add anything to it. Goes on dark blue and changes to black as it dries. Unfortunately it is not cheap. Paint brush works great as an applicator. Takes several coats to really deaden the sound. I want to buy a decent floor jack then raise my car up enough to coat the entire bottom. I use a combination of FatMat 2 to 3 layers thick covered with Spectrum Sludge. I will keep working on the front wheel wells until I am satisfied with the sound reduction.
Went with FatMat 4 layers thick and Spectrum sludge in the passenger side front wheel well. Figure I need to go big or go home. The combination of FatMat and sludge should help reduce road noises especially when driving on less than perfectly smooth black ice Asphalt. I hope to remove the plastic panels on the bottom of my car and put both FatMat and sludge on the belly pan under the front seats then replace the plastic panels and spray them with rubber spray since Spectrum Sludge says not to use on plastic surfaces since it may not adhere well.
The combination of FatMat and sludge has definitely took some of the tire drone away. I would like to jack my car and remove the plastic panels and FatMat and sludge the metal underbody right under the front seats. I drive about 35,000 to 40,000 miles per year and a quieter car is a nicer environment to be in.
what are the physical condition of the roads that you typically drive on? Like pots holes, cracks, bumps? Which tires are you running currently on?
Continental pure contact touring tires. I bought them at Discount Tire. Much better price than the Bridgestone Turanza quiettrack. Similar noise and ride characteristics but at a much better price.. Pretty quiet tire compared to some tires I used. Roads for the most part are pretty decent. Minnesota takes pretty good care of it's roads.
Don't do the underside. Pull out your seats and put under the carpets. Put it in a place that won't be exposed to the elements. Plus it will be much easier to apply.
