Noise Control Update

I started working on the sound abatement/control/contain effort in fits and starts over the last couple of months. Since I have been making some progress, I figured an update was due. I have only started the Constrained Layered Dampener (CLD). At some point I will be done with the CLD, and ready for the next layer. For more about my plan for noise control, see Hapy Noises Parts 1 and 2.

Sound Deadening

high-cost / high-value CLD

Sound deadening is slow-going stuff, even when you have time. The actual application of the CLD is fast and easy; getting access to the spots where you want to apply it is what takes a while. Some areas are virtually uncovered; like under the carpet in your trunk, the rear under the mattress of the camper bus is open bare steel. The metal gets cleaned with oil/grease remover, the largest square/rectangle of the highest quality deadener you can find is carefully applied and then you roll out any bubbles for a firm bond. In this way, the exposed steel was relatively quick work. I suggest you wear thin protective gloves because the edges of the foil layer can make tiny cuts in your fingers.

Accessing the Ceiling

To get to the largest sections of steel (the ceiling), I needed to remove the wood (Baltic Birch) headliner. The headliner is actually 4 distinct pieces: the rear, the front and 2 sides. Between the sections are channeled aluminum bits to hold the pieces together. Then, around the opening in the middle of the bus, a plastic pinch-surround holds the lip of the wood against the steel. The plastic pinch-surround removes with little effort: just grab and pull. In fact, getting this thing to stay put had been a bit of a challenge over the years. With some channel-lock pliers, tug on the aluminum channels, pulling towards the center of the bus, to remove them. With the channels and pinch thing gone, the rectangular piece over the sliding door fell right off. The one of the opposite side was held on by the '79 Westy interior 2-way light. Two screw removals later and the light and ceiling bit were free.

not quite done, but getting there

On Hapy, the rear section had been falling down for years, and I had resolved it long ago with self-tapping screws, through the metal ceiling. Recall, the westy was built on a "sunroof" bus model, so there are actually 2 ceilings (well, 3, if you count the Baltic Birch) with a gap between them where the sunroof would slide when open. Once I pulled the screws, the wood hung down in a familiar way. I simply helped what gravity had been doing by giving it a wiggle, and it fell onto the rear deck. This left the front section, which was quite snug. The internet instructions indicate that you simply need to remove the dome light and use that opening as a grip to pull the ceiling free. This did not work for Hapy, even after I removed the front shelf (See Sunshade to Shelf) I added, like, 6 years ago. Recall, the shelf was attached by re-using the sun-visor mounting points so it was a simple matter of removing some screws. With the shelf out of the way, I could get to the screws holding the 12V accessory plug, and then there were some very small screws along the front edge of the Baltic Birch which held the front lip snug against the front of the bus. After removing all the fasteners I could find, the ceiling still did not want to come down. I had to force it, and I accidentally split the driver side. I had no intention of reusing the old wood ceiling, but it would have been nice to give it to someone who is restoring theirs. Oh well.

Ceiling CLD

Once the front bit was down, I could see old-style fiberglass insulation had been installed between the drop ceiling and the steel, but only on the driver side. Perhaps the passenger side had been removed long ago. Regardless, I was not intending to keep it, so I pulled it down (wear gloves or you may get tiny fiberglass particles embedded in your skin. Ouch.), and scraped the glue residue off the metal with a putty knife. Similar to the rear floor, I cleaned and scraped and cleaned the metal in preparation for CLD. I used a combination of ResoNix (high cost / high-value) and the leftover Noico (cheap / lower value), hoping to maximize the vibration noise control. I may have overdone it, but I figured an extra pound of CLD might make a difference on the steel closest to my head.

rear half under top bunk

The ceiling in the rear had not been insulated nor had anything glued to it, so it was pristine metal. Still, it got the oil/grease cleaner treatment, and then multiple squares of ResoNix CLD. Recall that the sunroof model has 2 rear ceilings, and I had only addressed the bottom one at this point. The upper ceiling was much harder to get after. From above, it is covered with the floor of the Riviera-sourced upper bunk. From below, it has less than 2 inches of space between it and the lower ceiling. After mentally wrestling with how to deaden it, I decided to remove the plywood floor of the bed so I could apply material. There was simply no way to get good coverage 5 feet deep through a 2-inch tall gap.

The bed is supposed to be nailed down to the side rails with many tiny finish nails. In Hapy's case, I, uh... kinda didn't nail it down much. So, it would have been easy, had I not parked the bus where the pop-top would not open all the way. Instead, I could only get it halfway. So, I lifted the bed, pulled it as far forward as I could and then dealt with the noise suppression in 2 steps (rear half / front half). I took one extra step during the re-install, and added small squares of foam on top of the rails before setting the bed back in place. My thinking was that there would be less vibration and squeaking compared to the stock wood-on-wood. I will be adding sound absorbing material into the 2-inch tall cavity rather than on top, so I am hoping that I will not need to get under there again. Once I have confirmed that, I will send some thin screws through to hold the bed to the frame.

Exposed Metal

some easy-to-access steel

The last area, well, in terms of timing, this was actually my first, I addressed with CLD is the bare exposed steel around the bed along the sides. The keen eye will see that this is the Noico stuff. Yes, I did this area before I took the plunge on the ResoNix. Still, the tone of the tool-tap implies that the end result is less ring-y than without. Would the ResoNix had been more effective? Probably. Anyway, I mentally wrestled with applying material here at all because the rounded metal interior is part of the signature of an old bus. Arguably, so is the incredible racket you hear while driving. In fact, I used to drive by ear, listening for bad sounds from the original engine because the lack of instrumentation kind of forced me to. Anyway, the area below the window will ultimately be covered by a door/interior card. I intend to apply a headliner of some kind down to the tops of the cards, so the CLD you see in this picture will be hidden longer-term. 

Well, this is as far as I have gotten on the noise control stuff. Some of these steps were taken months ago, and others I just completed. That's just how life is these days: take many little steps and eventually you look around to discover that you have made some progress.

Thanks, as always, for following along-