Project #7 Roof Insulation
Well, the insulation paint finally cured on the interior roof. Although I had applied the paint as thick as possible, it dried very compactly. This was described on Hy-Tech's website, so I was not surprised. It did take about a week to cure and harden, but I imagine that was due to the low temperatures we endured all week. We moved Smaug to the house garage to install the headliner, since we were afraid that we would not be able to get the shop warm enough for the install.
First, we heated up the shop to a sweltering seventy-five degrees. (That temperature may be fine in the house or outside with air movement, but it is HOT when two adults are trying to work in a small space close to a propane heater.) We did the tapping test on the roof of the truck again, and there was a huge difference. What had sounded like an empty tin can before now sounded much more solid, almost like fiberglass. We worked to cover up the hole in the roof next. While not a permanent solution, we chose to cover the hole with a magnetic satellite radio antenna. We intend to install XM Radio in the truck later, so we decided to use the hole available to run the wire for now, at least until we decide to re-paint the truck. After applying the magnetic antenna to the top, and fishing the wire through the hole, we siliconed the antenna from the bottom, to seal any potential leaks.
Next, it was time for the automotive insulation. I had researched several brands, and even got a sample of Dynamat, but I had not found anything that I really liked. I decided to go out on a limb and order a Thermo-Tec product called "Suppressor Acoustical and Heat Mat". I ordered it through Amazon.com, and paid $49.95 for a 60" x 36" sheet, no shipping with Prime. When it first arrived, I had brought it inside and put it in front of the fireplace to warm up so that I could unroll it. It was a slow process, because the outer layer of the roll would warm, but the inner layers would not. This let me know that the heat suppression did work to some extent. We decided to install this layer of insulation in three pieces, driver's side, passenger side, and a 4"x4" square where the antenna wire came down. After taking some rough measurements and trimming, we test fit it in the truck...1,2,3,4 times, while we were trying to figure out how we wanted to put it in.
We finally reached the moment of truth and peeled off the backing and stuck it to the roof. We were a little concerned, because the mat did not seem all that sticky.There were some places where the mat folded while we were installing, but we simply made a relief cut, and let it overlap itself. We rolled the entire piece with a installation roller, and removed any and all air bubbles. Using the pieces we had trimmed from the first piece as a guide, we trimmed down the piece for the passenger side. By this time, the mat had gotten really warm in the garage, which made it slightly more difficult to work with. It was not as stiff as the first piece and wanted to fold. We were able to get away with only one test fit, and only needed to make two small adjustments before sticking it. This time, when we removed the backing, the mat acted very different. We had already realized it was more flexible, but the black mat (the side that sticks) was almost like a tar at this point. We got it stuck to the roof and removed any folds and air bubbles. When rolling near the edges of this piece, the black mat would actually squish out the sides, so we did have to be careful. We installed the last piece around the antenna wire, and re-rolled everything one last time.
After watching a presentation on installing this type of insulation, we did not stress about covering the roof 100%. Only 20% is supposed to be needed for sound, but we went for 95% due to heat. There were quite a few places where the black mat material had gotten on Smaug's interior paint, but Clorox Kitchen wipes took it right off and left the paint as good as new. It was now time for the roof sound test again. There was a huge improvement over the starting point and over just the paint. It now sounded more like hitting solid wood or a refrigerator door.
We had one more layer of insulation that we wanted to install before the headliner. We put two 24"x24" pieces of this insulation that we got from Home Depot on using a spray adhesive meant for headliners.
We then ran the antenna wire down the window pillar to the future radio location and called the project done. The one thing that I would like to have done, and will fix in the future, is add some type of insulation to the front lip above the windshield. That will have to wait until later because it is time to install the headliner!