Noise Control Continues

With Summer tour dates heating up, and our favorite festivals appearing to be taking the Summer off, I was lacking an out-of-town overnight show to really kick this effort into high gear. Well... Phil Lesh and Friends have announced Pacific NorthWest tour dates, hitting 2 of my all-time favorite outdoor venues: the Cuthbert in Eugene, OR and the Marymoor in Redmond, WA. Phil played these 2 venues back-to-back with Further in 2013 (See Tale of 2 Trips), so I conclude that these are his favorite NW outdoor venues too. Anyway, June 11 and 12, Phil will be at the Cuthbert and Marymoor respectively, and so will we. With that, we have some serious motivation to have Hapy buttoned up by the end of May. In that spirit, I finally got after the big sections of the floor, so today's post is all about that. 

Tear Down

starting the Jute

I accept that maybe I have been finding ways to delay the full-blown interior tear down. I messed with electrical (See Ceiling Wiring Rough In), built a replacement shelf (See New Cab Shelf), even messed around with the stereo (I will post on that once it reaches completion). At some point, I was going to have to remove the lot couch and the rock-n-roll bed so I could get after the floor underneath them. The lot couch removes easily enough, but the sliders also needed to come out so I could get the complete floor. Back when I first installed these runners, I mounted the runners with 17mm bolts. I added nuts underneath. I initially just loosened the runners and forced the Jute underneath. I later decided to completely remove the runners so I could get a seamless heavy vinyl sheet down.

My implementation of the rock-n-roll bed is held to the floor by a pair of Phillips screws holding a pair of arms to the rear deck, a 17mm bolt underneath, a pair of small nuts on a metal bracket mounted on the passenger side rear wheel well and a single 13mm bolt through to the fridge cabinet. The electrical bits, however, add to the complexity. I have my luxury fuse box under there, so I had to tear down what was left of that. Plus, the original Westfalia electrical includes the cables routing city power into the rectifier (110 to 12V converter) that's buried inside a wood box and running to the outlet on the front face of the bed. The box is held down with 2 Phillips screws and the outlet box is held by 4 Phillips screws. With the electrical separated from the bed, and the bed detached from the floor, I removed the cushions to manage the unit better. Each of the 2 cushions are held to the bed with 4 long Phillips bolts on each end (so, that's 16 bolts).

cabin Jute mostly complete

I would have completely removed the fridge cabinet, but the mounting of the furnace was so difficult, I did not want to revisit that. Just being disconnected from the rock-n-roll bed loosened it enough for me to fit materials an inch or so underneath it.

Constrained Layered Dampener (CLD)

I have probably posted enough on this material. Still, I applied on the now exposed floor areas. Parts of the floor had already gotten a light treatment in the little valleys, so on top of that I applied larger squares of CLD as well. I still have about a third of the box of ResoNix, with a plan to use some inside the sliding door. I have used some of the Noico around as well. For example, the walk-through partitions behind the front seats each got a large splat of Noico. I do not know if I will be keeping those partitions long term, so I did not want to spend the expensive CLD on those panels. Still, the Noico definitely helped reduce the clatter heard when I tap on the partitions with the roller. Of course, the whole floor and the rock-n-roll bed needed a thorough cleaning, starting with a shop-vac and ending with cleansers. 

Heat Wave Jute

MLV over engine

I was so excited to finally get to the Jute. I has felt like forever since I ordered this stuff and started working on noise containment. I started with a rectangle on top of the engine access hatch, with an extra couple of inches all the way around. I pulled the computer cover, and Jute'd the rest of the rear deck, and then moved forward. I fit a segment under the rear edge of the fridge cabinet, and doubled up over the front side of the rear driver wheel well. I pierced the Jute for the seat belts and a grounding screw, and set another piece of Jute up to the lot-couch rear slider and continued my way forward, covering the entire floor with rectangles. My method was to define as large a section as I could easily manage and then measure that out on the material. I marked the line with a sharpie and then traced the line with a box-cutter to start the cut. I made a second pass with a pair of scissors. I tried first with just the scissors, but the thickness of the material and 2 foil-faces were too much even for my best pair. As I set shapes down, the bus got progressively quieter. Without a radio, and just ambient neighborhood noise, there was not a dramatic change, it just felt more and more quiet. Very neat. One last observation about the Heat Wave: the foil top and bottom are electrically conductive. So, I would discourage use anywhere near open circuitry or be sure to insulate. For example, I took a section of excess MLV produced below and have it resting between the foil and the spare tire well where the engine computer and fuse box live. No sparky.

Lot Couch Rails

I had loosened the rails enough to force-fit some of the Heat Wave jute underneath, but decided that getting the MLV under the rails would be worthwhile. This meant removing the rails entirely. I had forgotten that when I first installed these rails, I ran bolts from above and nutted from below. Three of the 4 nuts were hidden by the radiator, so getting in there to free them was an all-morning exercise. Still, the nuts came free, the bolts pulled out and the rails were set aside. I took this opportunity to clean under the rails as well as install 4 riv-nuts into the old holes, so I would not have to go under the bus and reach around the radiator to deal with the rails again. That riv-nut kit is definitely paying dividends.

Mass Loaded Vinyl (MLV)

MLV continues

MLV is heavy; my goodness, it is heavy (1 pound per square foot). I found that the sound inside the bus actually brightened a little bit as I set it on top of the Jute, though. The Jute, in contrast, was simply amazing in how much quieter the bus seemed as I added it to the floor.  While I can't measure the impact of the MLV independently of the rest of what I am doing, I do wonder if the additional weight will translate into a corresponding reduction in noise. The SecondSkin web site has a noise transfer reduction table for the MLV that defines the reduction as anywhere from 14dB to 37dB, depending on frequency, with higher frequency blocked more than lower. We'll see. The actual absorption by the Heat Wave was noticeable. The table on the SecondSkin page for Heat Wave (in coefficient rather than dB) demonstrates very little in terms of dB drop below 500Hz: below 500Hz < 3dB, 1k: 7db, 2k: 14dB, 4k:19dB. So, the very high end will be controlled well and the low end not so much. I arrived at these numbers courtesy of the formulas on this blog post, converting the coefficients published by SecondSkin.

Anyway, the MLV delivers in a roll 54" wide. The bus is around 60-1/2" wide so rather than solve for a strip along one side, I laid a section 54" long front-to-back, covering the engine compartment and on down the rear wall behind the rock-n-roll bed. After cutting contours for the narrowing of the rear of the bus, I pierced the MLV for the seat belts and installed them. This took a considerable amount of time, mostly because of the challenges of getting the seat belt mounts in place. I continued with the next sheet of MLV, covering the mid-floor past the lot-couch rail mounting points (see picture above, right).

Re-Assembly

bed and rails in

I chose at this point to re-install the rock-n-roll bed. Unlike the seat belt mounts, locating and piercing for the bed mounts was much easier for some reason. With the bed in place, I pieced holes for the lot-couch rails and installed them. To make a more firm mount to the floor, I added a nut between the rail and the floor for the bolt to pass through. These nuts act like a 3/8" riser through the Jute material. I confirmed the width of the rails (12") and then torqued the bolts. Then, I put the lot couch back in. The couch slid in more easily than it used to. I think the rails were slightly below the lip of the sliding door before, creating some friction/resistance. With the little risers, the couch slides right in. The interior is pretty much the way I started the weekend. Yes, from the start to end of this post, it was 2 full-for-me (6+ hours) days of work, and some uncovered sections remain.

On a random mid-week afternoon, I added an additional strip inside the rock-n-roll bed where the 2 larger sections meet as well as a small piece inside the fridge cabinet. Last, the area just in front of the fridge cabinet shown in the picture above was addressed. So, from the seat partition rear-wards is pretty much done. That leaves the cab still to do. All of the seams need to be taped as well, but that should be much easier once the rest of the Heat Wave and MLV have been laid out.

In case you were wondering, that reflective material in the wall behind the fridge is foil-backed "RV insulation" that I had put in there years ago. It actually does reduce the temperature inside the bus a little bit, or it did when I first installed it. Since it does not fill the cavity, I will probably just leave it and put the Mega Zorbe or Jute right on top if it. There is the old Q-Quiet vibration absorber on those panels as well, and I will just leave that be. I am running out of material, and this project has taken quite a bit of time already.

That's it for today. Thanks, as always, for following along-