Burying the Brake Reservoir

This shorter-than-normal-but-actually-reasonably-length'd post was originally included within the second Hapy Seating post (See Hapy Seating - Part 2). I pulled it out into it's own post because the content stands on it's own, and the seating post was pretty long even without this. So, today, I will document the moving of the upper brake reservoir in the 1972 VW Bus.

Stock Reservoir

before image

Consider the original location of the upper brake reservoir on the 1972 bus is a tab/perch that juts forward from the driver seat partition. I clarify it by year because from the pictures I have seen, the reservoir appears in different places for different years. In Hapy's case, this perch sits, maybe, 6 inches off the seat floor with an opaque hard plastic hose attached to the bottom. The hose has a bulb at the top, allowing it to fit over the nipple on the reservoir. It is held on with a plastic clamp, and there is a rubber sleeve between the inside of the hose/bulb and the outside of the nipple on the reservoir. This opaque plastic hose runs down to the seat pedestal floor, and passes through a special hole in the floor of the pedestal. Within the pedestal, there is a cavity about 4 inches across between the inner wheel well of the driver front wheel and the outer edge of the pedestal. The opaque hose runs downward into this cavity and out a hole in the floor of the bus. Underneath, the hose runs forward about a foot to the master cylinder, upon which is another reservoir, that the hose attaches to. The hose connection to the lower reservoir is the same as the connection to the upper reservoir: bulb, clamp, rubber sleeve. Between the bulbs, the hose is narrower. The picture on the right, here, is from Hapy before I replaced the hose the last time. Note the rust, but more importantly, note the tab on the partition. Also, near the lower right corner of the rear-most square opening is the round hole through which the original brake reservoir hose passes. I do not have a picture of my original, complete, assembled set up, nor can I find any examples on the interweb. Trust that a square-ish reservoir hangs on that tang and connects to an opaque hose that passes through that round hole.

Gimme a Brake... Reservoir... Hose

pre-paint test mount

A while back, when I took that picture above, I purchased and installed a replacement opaque plastic hose between the remote, upper, brake reservoir (behind the driver seat) and the sitting-on-master-cylinder lower reservoir, but I did not shorten it to fit. It was "the" hose that was available, and was described as the right part for all buses and Vanagons. One size fits none again as the upper reservoir did not sit where it was supposed to. Just to hold it still, I zip-tied it to the driver seat partition through a pair of factory threaded holes near the top crossbar. It was not pretty, but it was functional and it didn't leak. So long as the driver seat was pushed back, no one could see how ratty the solution was. 

I wanted to fix this ugliness. I had mentioned the location of this reservoir in passing in the first post about the Sprinter seats (See Hapy Seating). I thought about the reservoir, it's location and the hard plastic backside of the 2016 Sprinter seat, concerned whether the brittle plastic reservoir in the original position would get run into if the seat was pushed back to the partition. Fairly sure the two unforgiving plastics would hit each other, potentially cracking the much older reservoir, I moved it inside the pedestal of the front seat. It can now be accessed through a pre-existing square-ish hole in the pedestal, near the rear of the seat. The picture on the right, here, shows the new location. I may get creative with a cover when I do the carpet or I may leave it exposed, but that's a decision for another day.

Re-Locating the Brake Reservoir

I started by MityVac'ing a bunch of brake fluid out of the hose, down below the stock mount point. Before I made the decision to simply move the reservoir, I tried to shorten the plastic line. I cut the hose, heated it up and tried to force-jam it onto the filler. Yeah, that doesn't work. I could not figure out how to make the "one-size fits Vanagon - otherwise you're on your own" hose to fit. Additionally, the plastic is too hard to wedge a 2-sided nipple in a line breach, so a simple cut and double-barb solution wouldn't work. I abandoned that plastic line and started seeking a rubber line solution.

reservoir in service

The hose barb on the original reservoir accepts a 12mm hose. Flexible 12mm brake hose is not easy to find in lengths greater than 4 inches around the usual online sources for some reason, and those short sections are crazy expensive (like $8US before delivery charges). However, a half-inch hose is only .7mm bigger, and those are plentiful, here in the US. So, I ordered a 2 foot length 1/2" Department of Transportation (DOT) -rated brake hose, and ran it from the master cylinder up under the driver pedestal, through the original hole in the floor. The hole through the floor needed to be expanded, however. I do not have drill bits that big so I used a sledge-hammer and an old 2-ton floor/trolley jack's removable handle (as a chisel) to smash the hole larger. Yeah, that felt a bit destructive, but it only took about 4 or 5 whacks with my small sledge to drive the jack handle through. The jack handle was completely unmarred by it. Once expanded, the hose slid through the hole.

I fit the upper connection first, and completed with a clamp. The hose settled onto the plastic nipple, but I unexpectedly needed to use a touch of force. I had thought that .7mm would have allowed the hose to slide on and slop around. I was pleasantly mistaken. Then, I slid underneath and figured out the correct length of hose. Once the length was decided, I cut it with tin snips, and mounted with a clamp. I mounted the upper reservoir to the side of the seat pedestal last, filled it with brake fluid and checked for leaks. I stepped on the brake pedal a few times to create some pressure. Finding no leaks, a firm brake pedal and feeling quite satisfied, I called it complete.

Oh, the 2016 Sprinter seat easily slides back over the top of the reservoir with plenty of room to spare. Like multiple inches to spare. As to what would have happened had I pushed the seat all the way back, I'll never know for sure. But, the rear of the seat comes within an inch of the little tab thing, so they would definitely have collided.

That's it for today. More next time-

Hapy Seating (Part 2)

When the nice weather (read:camping weather) got behind us, I pulled Hapy off the road to swap out the seats. That was before we got a puppy and my wife changed jobs. I have been doing bus-related things when the rare opportunity presented itself, of course, but these seats just were not getting my attention. I have finally gotten these seats installed. So, today, I will wrap this up.

Out With The Old

Sprinter seats

Recall, we removed GratefulEd's donor seats and stowed them safely in my garage. They will go back to him as soon as these new seats are confirmed viable. The stock passenger seat is held in by a hook-loop between the seatback and the steel partition, and a pair of C-shaped mounts that point up. The seat was designed to remove quickly so you can access the tire jack usually stored beneath. You lift up on the front of the seat, folding it slightly, the hook on the rear slides out of the loop, allowing the seat to be lifted straight up. Pretty clever. The driver seat rides on 2 slides, and is held in place with a more modern toothed rail concept. Like a modern seat, the adjuster unlocks by lifting on a bar under the driver's right leg and then the seat can move front to back. If the bar is lifted and the seat is slid all the way forward, it slides right off the channels. Easy-peasy.

With the stock-ish seats out, we can consider the install of the new seats. In the 2016 Sprinter, these seats are mounted with M10 grade 10.9 (or grade 8 in SAE measures) bolts/nuts. Unable to source these at the local Ace, I had to patronize the Home Despot for fasteners. Moments like this I miss Orchards; their fastener department was massive, well stocked, clearly marked and there was room for multiple shoppers. Anyway, I mentioned in the last post that the "C" mounts for the passenger seat blocked a clean mock up of the new seat on that side. On Hapy, the inner mount was held on with 2 small (10mm head) bolts. The outer mount was welded on (presumably by a PO). So, I removed that one with my angle grinder, a hacksaw and a hammer/chisel. I generally do not like cutting original parts off the bus, but I am fairly sure the outer hook was supposed to be bolted in like the inner hook was, and a prior owner performed a repair or "improvement". I'm going with repair. The loop on the partition is held on with 2 more 10mm bolts. All of these parts dropped into a zip-lock baggie to be misplaced for the foreseeable future in my disaster of a garage. I'm not kidding; I have already lost track of this baggie.

While We're Here

Three of the most dangerous words when it comes to projects are "while we're here". Still, there are times when it makes sense to do something while you are there and things are exposed. For example, you need to remove the air cleaner to get to your spark plugs, so you replace the filter during the out-then-in. That didn't really increase the scope, and you were touching it anyway. In this case, I have very little interest in removing these seats again once they are in, but I know they will be out and back in again. Resisting the urge to do more, there are a few things worth doing while your seats are out. After pulling out the old passenger seat mounts, I spent a little time improving that seat pedestal. I cleaned up all the dust, debris and spent horsehair. I hit some surface rust with rust converter and then topped that with some spray paint. I do not have carpet yet, and I don't want to put the old pedestal wrap carpet (basically trunk carpet) back on. So, yeah, these seats will be coming back out for a carpet install. I hope to install that carpet before Summer travels begin, but it could just as easily happen years from now, which is why I did the rust-treat and paint.

 

Measure, Template, Mark, Repeat

templating

To determine the correct placement of the holes, I started with an 18" x 18" square cardboard template. This matches the length of the seat rails and the distance between their outer edges. I held this template against the bottom of the driver seat, and marked where the mount holes needed to be. Once bored out, the template was ready. I set the driver seat in place and to mark where the front of the seat rails needed to be. Hmm.. the new seat's seat rails are longer than the original. They are so much longer, in fact, that they hang off the front of the pedestal by about an inch so I re-drew the front holes on the cardboard template for the front mounts. The next available hole rearward is about 2 inches back. This places the new hole squarely within the pedestal. Since the seat location is not as clear from the front of the rails (due to the drop in the front before the end of the rail) as the rear of the rails, I marked the pedestal along the rear edges of the rails for the template to align to. After removing the seat, I aligned the template with these marks and then marked where the holes needed to be. 

I test fit and marked where I thought the holes should go and then measured for straightness. And then repeated that cycle until I had the planned seat mounts square. Before boring the holes, it is worth considering that 2 of these holes will pass through the wheel tub into the area where the tires are. Accordingly, getting bolts that are not too long is very important. I got 25mm long (M10 grade 10.9) bolts so they are long enough to pass through the rails, and the steel tubs without protruding very far into the wheel well. While there is enough thread on the bolt in the wheel well for the nut to bite, they are short enough that the tire could not possibly touch it. The passenger-side rear bolt, actually, just has enough thread on it for the nut to fully engage, with no part of the bolt protruding through. The pair of inside bolts, on the other hand, remain inside the seat pedestal. These nuts are hard to reach, but there is plenty of meat on the bolts for the nuts to grab onto. Once I have carpet installed, it will be quite difficult to get a socket on them. I will need to form a flap with the carpet so I can get in there.

 

One thing I found interesting while doing this: the stock driver seat is not square. The front edge angles slightly towards the center of the bus, so as you slide the seat forward, the seat slightly shifts towards the center. I did not duplicate this, but it is interesting.

 

Drillin'

My drill bits have not improved since the rear anti-sway bar install (See Handling the Handling - Rear Anti Roll Bar), so I slowly drilled the holes into the seat pedestals. I had intended to tap the holes so the bolts would thread into the seat pedestal before they were nutted from below. This plan was set aside when I considered how far under the seat the front bolts would be and how hard it would be to wrench them down. So, instead, I bored three them all the way out so the bolt would drop through the holes instead. I did tap the outer rear hole. Once all four holes were drilled out on the passenger side, I set the template in place and set the bolts through. They lined up perfectly. Sweetness.

both seats in. pardon the trash

With the holes for the passenger seat drilled out, I pretty much duplicated the hole locations for the driver side. On the driver side, I chose to drill straight through the original seat rails. I keyed off of an existing hole in the rear outer seat rail, since the template was almost there. The outer holes simply align with the template. This decision prevented some alignment issues, and also set the holes in spots where the original seat rail would not get damaged, and could still be used. This allows for a future decision to put original seats back in, and it provided a couple of additional layers of original German steel, adding to the strength of the overall install. I drilled out the 4 holes in the same stair-step method of drilling out the center hole with a super-tiny bit and bore it out wider with progressively larger bits until it's big enough for the bolt to drop through.

Driver Pedestal

Similar to the passenger pedestal, the driver pedestal got a clean-up, rust treatment and paint. Unlike the passenger side, however, the rust was more prevalent. I think the leak from that old plastic hose from the remote brake reservoir to the master cylinder caused it. So, I included some Eastwood Rust Encapsulator in the treatment. I got completely under the pedestal as well as the mount holes I had just drilled out.

 

Mount Up

With the holes drilled out, it was just a matter of patience getting the bolts in and tightened down. Since the front bolts are buried inside the seat rails, I started with them. I tipped the seat back a touch and wiggled the bolts into the runners so the bolts hung down. I set the seat in place, letting the front bolts fall into their holes. I figured these were harder to solve for than the rears, since I could slide the seat forward to get to those bolts. I lifted up on the seat adjuster and slid the seat forward enough to be able to directly manipulate the rear bolts. The inner rear bolt dropped through easily, and I was able to thread the rear outer bolt into the tapped hole. Once snugged, I threaded on the nut and tightened it down. Then, I set the nut onto the inner rear bolt and slid the seat back. The 2 front bolts were difficult to address with a wrench because the upper slider did not slide past them when the seat was most rear-ward. I was able to hold them in place with a bladed screw-driver while tightening the nuts from below, however. I accept that this means they may not be torqued down as much as any of us would like, but that's how it goes sometimes. Also, I omitted washers from the inner bolts, simply because I didn't have many.

Left Undone

The rear bolts on the driver side encountered some issues that I will need to address. The inner bolt hole intersected with a support rib, so a nut currently cannot fully seat. I need to get in there and trim the rib back. The driver-side outer bolt hole encountered a contour within the wheel well, preventing the nut from setting. This will be easier to resolve: bfh (big fn' hammer) to flatten the contour. I will solve these when I do the noise control steps since I will need to remove the driver seat anyway. I will include washers and will get the fasteners torqued down then too.

Test

At this point, both seats were in. So, Boo and I took a test drive. In our driveway. Without starting the engine. Okay, the test consisted of the two of us simply sitting in the seats, listening to the radio enjoying the new front speaker set up (See Returning to Hapy Sounds Part 1 and Part 2) and imagining the first camping trip. We will have a real test when Hapy is back on the road. I have moved Hapy around the driveway with the new seat. It is firm and supportive, but high. I can't tell yet if it's bad, it's just different. My feet can easily push the pedals all the way to the floor, so there is no safety issue. I will just have to get used to the higher viewpoint.

Tuukka's garage seat

As you can see from that last picture, I have started applying some noise control in the form of vibration deadening material onto the cab ceiling (some ResoNix, plus some leftover Noico). Of course, I am already asking myself whether I should remove those seat partitions, even without adding swivels, so the seats can recline farther. It seems like there is always something to do "next time". Perhaps the most important thing at this point is that I can return the old seats to GratefulEd. Tuukka, the dog, will very much miss them as they have been his go-to spot while hanging out with me in the garage.

 

My last 2 posts prior to this one contained a great deal of idea-mulling. As I just mentioned, I have started some efforts in the noise reduction space and will continue as time allows. Between clearing the spots where it will go in the bus and the careful application of it (lots of measuring and test fitting for the layers above the CLD), there's a lot of time spent which does not translate very well into posts. Still, I have a few other little things I have going on, so I will wrap those up around the noise-contain work so I don't go too many weeks without posting anything.

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

Hapy Noises - Part 2

Today's post continues the thinking-through-my-fingers on noise containment in Hapy, the 1972 camper microbus powered by a turbo diesel engine from a 1998 VW Beetle. This time, we look at the layers of noise control which appear on top of the vibration dampener I mentioned in part 1 (See Hapy Noises - Part 1). Then, I cover some decibel collection I did so we have a starting point for measuring success or failure of the various layers.

Sound Absorb

Second Skin Heat Wave (Jute)

With the Constrained Layered Dampener (CLD) chosen, I wanted to add noise absorption stuff as well. In my research, I arrived at 5 different product types that could help. There are plenty of other choices, but I think by combining these, I will achieve my noise control goal. These act differently and have different strengths, so some are better in different locations and some are best used together.

Jute Thermal - absorbs sound, but is really more for temperature containment. This is similar to old-skool car insulation, but it is lightweight, and actually does absorb some noise. I intend to put this (HeatWave) over the engine compartment, under the rock-n-roll bed (on the floor) through the main cabin, under the front seats and to the front kick panels. It will act as a 3/8" thick carpet pad while keeping road noise and heat down. The Heat Wave product is designed to resist mold, etc, so even here in the rainy Pacific North West, it is safe for use. Of course, getting it soaking wet is not advised, so some thought about where it should be placed is suggested.

Second Skin MLV

MLV (Mass Loaded Vinyl) - blocks the transfer of airborne sound. Some products have integrated foam to absorb sound as well. These sheets are heavy for their size, and folks have expressed difficulty in getting them to hang vertically (like on a wall) or horizontally (on a ceiling, eg) permanently. I intend to use this stuff (Luxury Liner) from tailgate to toe-kick: under the seats, the rock-n-roll bed and the entire floor on top of the jute. By having the jute layer in-between, the MLV is more effective. The audio guys use this stuff behind their door cards too, but I'm not sure I'll have the money nor patience for that. The luxury liner is 1/8" thick, so, anywhere this goes on top of the Jute, the carpet will effectively have 1/2" of pad, which would be a little thick anywhere people are walking around, but the MLV will effectively stiffen the underfoot feel. It won't feel like you're walking on a 1/2" cloud. Using it under the seats will be fine, provided it doesn't interfere with the operation of the seat. This stuff is super important for noise containment; the audio experts / competitors swear by this stuff. I am toying with the idea of creating a "box" of this stuff inside the engine compartment to really cut down on the transfer of the engine-din. I'm not sure how that would all work. Again, thinking thru fingers.

Second Skin Mega Zorbe

Acoustic Foam - There are literally hundreds of different acoustical foam in all kinds of contents, shapes and sizes. Most are not all-weather-safe, and some are rather thick, so the options for smaller spaces where water or humidity might appear reduce that list from hundreds down to tens. That's still a big list. I plan to use this stuff (Mega Zorbe) in the doors, walls and in the ceilings. Of the materials, this is the most expensive, but it may be the most effective in dropping the overall noise. It is 1/2" thick, so anywhere it goes it could make it's presence known, so I can't use it on the door cards, for example, but it can go into every body cavity. There is definitely 1/2" between the wood drop ceiling and the steel, so even after that wood is removed, we would not lose headroom by adding the Mega Zorbe to the ceiling. Omitting the wood drop ceiling removes a sound reflecting surface I would otherwise need to deal with as well.

Open Cell Foam - I will be putting something on the door cards. I may use an open-cell foam product. Second Skin doesn't offer anything, but that's because there really isn't a product that will meaningfully absorb sound that's less than 1/2" thick (aside from the jute) and they are in the sound control business. I want something that will soften-to-touch and maybe reduce some of the sound reflection. For that, any old thin foam would do, because pretty much any soft surface that's, like, 1/8" thick will reduce the sound reflection. Or so they tell me. I will probably order something from McMaster-Carr (like this) or foam by-the-yard (like this) from FoamMart unless I can find something from an automotive fabric place. Regardless, any time we use open-cell foam, it is best to put a moisture barrier material between the foam and fabric (like this) to protect the foam from moisture as well as protect the fabric from rubbing against the foam. I haven't decided if/how I will address the hard cabinet sides. They might get the foam/fabric treatment just like the cards.

Closed-Cell Foam  - Similar to the open-cell foam in terms of flexibility and possible uses, but closed-cell foam is not permeable, so water can't get into it, damaging it. Closed-cell foams are usually stiffer and do not absorb sound as well. I may use closed-cell foam for the door cards instead of open-cell, if I can find something that acts like an open-cell, but is water-resistant (like this Volara or this Ensolite). There are closed-cell products designed for placement between your plastic bits and the steel. I had thought about getting some for between the cards and the body. I still may, but the rough cost of this effort is already a bit nutty and I can always do that later. For now, whatever foam I put on the door cards (under whatever fabric I put on there) may simply wrap around to the backside. Hopefully, that will contain the card-to-body rattle. Of course, I may just omit foam and fabric on the cards if money and time are not available.

 

Noise (dB) Level Tooling

Before we do any of this great stuff, I want to know where we are starting, so we can measure and celebrate the gains. My sitting-in-seat frame of reference for noise: I needed to run my stereo at 25 or above to be able to hear it at all over the noise of driving down the highway on the way back from Hapy's birthday (See Hapy Turns 50). I had the volume at 30 for loud-enough-to-sing-along (but not entirely taking over) volume. That is not at all scientific. So, in the Fall of 2021, I set aside the new driver seat install, took Hapy for a spin with the old seat and recorded these values for future comparison. My "tooling" was a free iPhone application called "Decibel Meter". I chose it because the free version allowed me to save many recordings, complete with graphs, for looking back upon. I was also able to email myself 5 minutes worth of detailed data. None of the other apps which also have a reasonable scale for the dB provide those features for free. I tried a few apps I won't name which had completely inaccurate dB readings. I used "Decibel X" as my control for comparing other apps. Decibel X is great, and very accurate, but you can't record more than 1 session, nor share anything without a hefty fee. I would have used it for my tests, but I would have needed another person in the bus, watching the meter, writing things down. That's silly.

I thought about buying a measuring tool for better sampling. I decided that I was already uneasy about investing a considerable amount into solving the problem, and chose not to spend more on a measuring device. Having better calibrated results, and more accurate frequency levels would have been great. The issue is that a decent point-in-time tool (Extech 407730) is at least $80US. An OSHA-qualified tool (REED Instruments R8050) is closer to $200US without data logging, while a fully functional tool (like Extech 407750, or REED Instruments R8080) can be over $300US. Plus, you need an additional device to periodically calibrate the instrument (for another $100US or more). I'm sure these devices are better than my free iPhone app, but I need that cabbage to cancel the noise first. Having said all that, if this sound control thing is a fun project, I may get a good tool so I can better measure before and after on future car projects. The trick will be finding one that is reasonably priced, accurate, can be easily re-calibrated and has a logging function so I can collect 30+ minutes of data without having to write things down as we go.

Noise (dB) Level Tests

For the test, I idled in the front driveway, and then took our usual route to the highway (OR217) from home, and drove a loop (OR217 - US26 - Murray Blvd) back home. This got multiple samples of idling, around town and byways. I only got one real highway sample, but I think it was long enough. I got up over 65mph for a short stretch, long enough to collect a sample.

Decibels from that long test are below. One important observation throughout all of the tests: the dominant frequency of the noise appeared at the very bottom of the spectrum. This could be a reflection of the tool not reading frequency well, or my noise problem is 95% below 100Hz. Some comparisons on my couch between the 2 apps indicated that Decibel Meter reads Hz low when compared to Decibel X. Neat. I chose to ignore the Hz, and accept that I can only really measure overall dB. On to the dB readings! In all cases, the value moved around within a range as well as had an overall peak:

dB test as a graphic

Sitting at idle (900 RPM): 60dB

Around town (less than 40mph): 65dB +/- 5dB. 75dB peak

On the byways (above 40 but under 55): 65dB +/- 10dB

Highway speeds: 70dB +/- 10db, 83dB peak

Over the course of the 30 minute test, noise was consistently between the mid 60's to mid-70's with spikes up into the mid-80's.

For fun, I compared against Boo's 2009 Audi A4 (GoRo) on my old standard test-drive loop, and then ran Hapy on that same test loop. This loop does not include a highway, but it does include idling, a residential street and a 4-lane "by-way". The Audi ran from the upper 40's to the lower 60's. Hapy on the same loop was in the low 60's up into the lower 70's, topping at 75dB.

Noise (dB) Level Test Thoughts

In simple comparison, GoRo was in the lower 50's most of the time and Hapy was 10dB louder or more. "10" seems like a small number, but I consider these 2 things: First, the range for both vehicles remained within about a 10dB span with Hapy's quietest/lowest readings starting at the loudest/highest for GoRo. Second, a modern refrigerator or a moderate rain is 50dB and hearing damage starts at 85dB, so a 10dB difference in this range is actually huge. I think it is kind of like 10* difference in Celsius: 23*C (73*F for US folks reference), is totally comfortable, like a conversational 60dB. But 33*C (91*F) is intrusive-hot, like a running vacuum cleaner 70dB. Another 10*C (43C or almost 110*F) is quite uncomfortable in practically all climates, like listening to a whistling kettle (80dB) for an extended period of time would be. For some real-life decibel level references, I found this link to be especially fruitful. Last, I think it is worth noting that the highway was much louder. My usual shift point is around 3200 RPM, and I cruised the freeway around there as well. So, maybe the noise gets much louder above 3k RPM -OR- the increased speed leads to more noise (wind or tire). I can't know for sure without more tests, but I think resolving the highway noise will be my biggest challenge. It would be the greatest reward for longer trips, if I can solve it.

EDIT: I added the image just above  on the right on 2022-Mar-29. I sourced it from a research paper about the dominant frequencies produced by a 3-cylinder diesel engine. While this may not be an exact match for a 4-cylinder TDI, I think we can draw sufficient parallels to lead us to focus on frequencies above 250Hz, but especially around 1k. Based on the material sheets for the items described above, all of these should make a meaningful impact on containing the noise.

That's it for today. I have more planning to do, and things to purchase. If all goes as I hope, the noise control efforts will start soon. My goal is for Hapy's entire noise range to drop by at least 5dB on the test loop and for the mid-80's highway peaks to drop by at least 10dB.

Thanks, as always, for following along-

Hapy Noises - Part 1

Today, I share my thinking around how to reduce the din when driving Hapy. He's a 50 year old bus. He runs a turbo-diesel engine. How quiet do we want to be? Or should I say how quietly do you want to spend? Or, maybe, how quiet do I really think this can get? I am actually taking this on, slowly, over the course of the winter and spring with hopes of a more comfortable drive experience when camping season really open up. For now, I will just put my think into words because what's a car person to do when s/he can't work on their cars? Thinks about them. Like so many posts, this got really long. So, I split this up. Today's post will cover controlling the resonation effect with constrained layered dampener material.

Before I begin, Hapy Groundhogs Day. Regardless of what the critter in PA does, it will always be 6 more weeks before the Spring Equinox. Here in the Pacific NW, it will rain until then. With expectations set, let's go.

Constrained Layered what?

Other places do a better job of explaining this. For our purposes, a Constrained Layered Dampener (CLD) reduces vibration by transferring that vibration into heat, which then dissipates. These materials have 3 basic components: the adhere layer, the butyl layer and a foil layer. The adhere layer is obvious: it is the super-sticky that gets the CLD to stick to the metal that vibrates. The foil layer is also sort of obvious: this is the top layer that you see when it's done. The butyl layer is the key: this is the science part that accepts the vibration from the adhere side and the vibration-resistance from the foil side. The butyl does the work of trying to get the vibration to stay put by equalizing between the two layers. The better the quality of the butyl layer, the more effective it will be per square inch. Again, there are better explanations out there, but that is a basic high-level summary.

Noico / FatMat / Hushmat / Kilmat

When I did the work on Oliver (1978 MGB), I used the Noico noise deadener stuff sold via Azn. I had read around the web that it was pretty good stuff, but when you are reading about what amateurs did on forums, it quickly becomes an echo chamber. Many forums dedicated to home-wrenching have posts that ask about one or more of the products listed above. Since most folks only ever use one on that one car, and aren't doing it professionally, the general consensus on Noico is "it's good". For the most part, the testing I have seen put all of these (Noico, FatMat, Hushmat, Kilmat, etc) in the same mediocre category. They sorta work, but you need a lot of it for it to get anything out of it.

Slamming Amazon side-bar.... Azn is excellent at hyping a mediocre product; this happened with Noico. We, as consumers, are led to believe that the marketplace will decide, and if people give positive reviews of something, it's probably fairly good. This works for products or services with which we all are somewhat familiar. Want advice on a TV or a phone? The market will weed out the garbage eventually. The issue is created when someone buys an inferior product about which they know little in a product market about which they also know little. Their experience goes from sucky before it arrived to perceived slightly-less-sucky. So, they think the product is fantastic, because they think life got better. What they may not realize is that they really did not make their life that much better, if at all, for the money they spent. They invested a small amount of money (like $2 per square foot for Noico) and a bunch of time, and when the noise in their car seemed reduced, they figured it was the product. Maybe it was. Maybe it was simply from removing the panels, cleaning a bunch and putting them back on. Most likely, the reduction was not as great as it could have been had they used a genuinely good product. The misperception is then influenced by the amplification of the echo chamber and the desire to not be taken advantage of, so a belief that the product was good is formed. And, the feedback loop continues.

In the convertible, I didn't know any better and, frankly, it doesn't really matter. It is a convertible running a carburetor and an aftermarket header; it will be loud when driving around. That's actually part of the fun: put your foot in it and it goes "waaah!". I put the Noico in the doors and now they have a nice "chunk" noise when they close. Same goes for the trunk. I think the overall din from the drive train is lessened because of the full-floor (both cabin and trunk) install I did plus the liquid rubber liner, the insulation and thick carpet. Exactly how much the Noico helped is unclear. For Hapy, I have way more noise control opportunity. It is not a convertible, and there may be 4 times as much steel panel to resonate-control. I had put something on some of the panels years ago (like the old brown bread, delivered in a roll, smelled bad), so it is not completely bare. I don't think that stuff was terribly effective, but it was what was available 15 years ago.

DynaMat, Second Skin and ResoNix

For learning about quality, viable noise control, I hit the car audio forums. I figured that if they were using something that helped them win car stereo competitions, it would probably do a good enough job lowering the noise in Hapy from incredible racket to tolerable. At least, they would know which lower-price options were actually worth using. In my research, I also engaged with Second Skin audio, and will use their stuff above the CLD (constrained layered dampener), which I will detail in another post. For vibration noise control, though, I am using ResoNix CLD. This stuff is super expensive, compared to Noico, but only a few cents per square foot more than the Second Skin stuff. DynaMat usually appears at the bottom of this higher-quality group, by the way. Based on the testing evidence on the ResoNix site and in the audio forums, the ResoNix stuff is really next-level. In the end, I will need to apply far less material than Noico, which means less work and less weight, while enjoying better vibration noise containment.

Install How

Install for any of these products is simple: clean the area to practically food-grade clean, measure and cut to fit with scissors, pull the backing paper and press it in place. Then, with an installation roller, roll around on the foil to get any air bubbles out and to ensure a quality adhere. Don't damage the foil; I can't emphasize that enough. Also, if the surface isn't clean, the product will not adhere as well, defeating the purpose. The amount of CLD you use is directly related to the product you are using, though the larger the uncut piece of CLD you use the better it will work. Meaning, if you use a bunch of small pieces over a section of metal, it will be far less effective as compared to one single piece. The strength of the CLD effectiveness comes from the foil topper preventing the panel from moving. This forces the vibration energy to change shape into heat energy as the Butyl tries to adhere to the metal yet retain it's shape as defined by the foil topper. If the sheets are tiny or if there are tears in it, there is less constraining, so more room for the metal to move, and much less of the vibration is converted to heat energy.

I found 2 different types of rollers on the market. The one in the image below has a completely smooth roller for foil-contact. While it may lose traction on super-smooth foil, it will probably not accidentally tear the foil. I say "may" and "probably" because I bought the other kind that has ridges running across the roller surface. That kind of roller can tear the foil, but it definitely does not slip. Ask me how I know :) Buyer beware, and if you get the same kind I did, mind you don't get too zealous with it or you may apply splits into the foil.

Coverage

Something like Noico will require nearly 100% coverage to get anywhere near the same amount of dampening as 25% of something high end. Under-apply and the vibration noise may just lower in frequency, not the full resonance so the vibration does not actually get resolved. So, you will think it's better, but you just lowered the note. If you watch car shows on Speed/Velocity/MotorTrend, you will see that those guys cover 100% of the interior and trunk (though they never broadcast the application. No sparks = bored producers). If you have the money, and haven't a worry about weight, I imagine doing the entire car, covering every square inch like that, provides maximum vibration reduction. There are diminishing returns though. Some small areas hardly vibrate / amplify car noise at all because they are small or have multiple connection points and can be skipped. The key to maximizing your product application / minimizing cost is to focus on the large flat sections first. Whether material should be multi-layered is a frequent question. The common understanding, demonstrated with some testing, is that layering product is money and cost ineffective without much return. That doesn't stop folks from doing it. Your project, your choice. I would suggest what the high-end manufacturers say: if you are willing to buy multiple layers of less expensive stuff, why not buy the good stuff for the same price and far less work/weight?

When I apply CLD, I can't help but tap on the area with the roller handle before and after I apply it so I can hear the difference. Before, it sounds tinny, after, it has more bass. Is this a reflection of what the vibration effect will be? Oh, heck no; I just can't help doing it. It feels like you're doing something. The only real tell is after you're done and you go for a drive. With Hapy's diesel engine running, we will get a fairly good idea without actually getting out on the road. My hope is that after I have finished, driving Hapy will no longer feel like you're operating a diesel generator inside an old leaky steel shed during a wind storm.... like it does now.

Liquid Deadener

One last thing on deadening: there are liquids that deaden too. These fall under the Liquid Applied Sound Deadener (LASD) umbrella. Second Skin sells "Spectrum" (see here), but there are others, like LizardSkin, dBSkin and QuietCoat. Since these products target the same thing as the CLD does, I thought I would mention it here. Based on the studies and the science of the CLD, I am not convinced the liquid works as well. The product websites don't specifically say how effective they are in decibel reduction terms, but for hard to reach spots where getting a sheet of CLD is not practical -OR- for exterior areas like the under body or wheel wells, this may be better than nothing. Or, this could just be fancy marketing of what amounts to liquid asphalt painted onto your car, reducing noise like a cheaper CLD does simply by being a thick coating. For the coverage, the liquids are much more expensive per square too. Still, I am going to try Lizard Skin in the spots I can't reasonably get to with CLD (wheel wells) because I want to try it out. I may hit between the belly pans and the floor, since I can't get in there with anything other than an undercoating nozzle. If it does little for the noise, but it helps retard the rust, it would still be worth doing, IMHO.

Next time, I get into different materials for subsequent layers, as well as some decibel readings for a "before" image to compare against after I add some of this stuff. Thanks, as always, for following along-