Sound Deadening Project like no other

[scampo77 0]

I am very interested in this topic and after a google search I kept being redirected here, so i signed up. i read don's forst pinned post ashphalt vs sound deadener. i must say my opinion was the same as the examples "well it worked good till it fell off on the second hot day" and i was "that guy" saying stuff like "hey you can get that stuff from home depot" well i am willing to conceed and try a different aproach for this new project.

my vehicle is a commercial truck, a 5 ton like a moving truck you probably see making deliveries in your city. i have no hood, it is a tilt cab so i sit directly overtop the engine and cooling fan. after a HP upgrade and a 2nd turbo charger i now have to drive with ear plugs in when i am on the highway and when the fan comes on i just cringe.

I have brain stormed with other people and some of the ideas I/we have come up with are....

-i wanted to pour concrete into the floor pan with chicken wire as rebar

-washed garden stone in a polyester (fiberglass resin) put this down on the floor pan

-full blown highway ashphalt

-cement sandwiched inside fiberglass (like a concrete eskimo pie)

-those thick rubber stair covers for outside steps cut and screwed to the floor

-welding a iron "turtle shell" overtop the engine and rad

Right now I have decided to go with fiberglass and resin like building a hottub, I am almost done and I have put down .75-1" of various fiberglass products down on the floor. it will be smooth when I am done and thick like crazy. I WAS going to put down the tar roof stuff from home depot on top of this, untill i found this forum.

Aside from mail order stuff what can I use from the local hardware store after the hottub floor plan? should i be looking for something like neoprene? or a thick rubber? or am i forced to buy actual engineered sound deadening products?

right now i am trying to patch all the manufacturing holes, rust holes, imprefect seams in the construction of the car. i keep setting off smoke bombs in the cabin and chasing the escaping smoke and patch the holes with fiberglass. i figured getting all the holes patched would be a good first step.

any ideas would be greatly appreciated.

[Impious 1,476]

So what exactly is your goal? Are you trying to stop vibrations, kill noise from the engine, or both?

How much does the fiberglass you have in there now weigh per square foot?

[ssh 924]

To deaden the cabin your going to want mass, and Don's MLV is perfect for that.

[scampo77 0]

How much does the fiberglass you have in there now weigh per square foot?

A LOT!! but its still lighter then washed garden stones

I am trying to stop everything as much as possible, I am after every dB I can get. I spend 40+ hours a week in my truck and i am going deaf. I see people at SPL contests just put like 18" of concrete in their cars. its a bit excessive but i just figured it was the way to go.

if all i am after is mass then can i just do the the washed stones in polyester idea? I cant think of anything with more mass or density the stone.

[ssh 924]

How much does the fiberglass you have in there now weigh per square foot?

A LOT!! but its still lighter then washed garden stones

I am trying to stop everything as much as possible, I am after every dB I can get. I spend 40+ hours a week in my truck and i am going deaf. I see people at SPL contests just put like 18" of concrete in their cars. its a bit excessive but i just figured it was the way to go.

if all i am after is mass then can i just do the the washed stones in polyester idea? I cant think of anything with more mass or density the stone.

I don't know enough about it to tell you one way or another exactly, so I won't point you in the wrong direction, but I know as far traditional car audio sound deadening products go, the thick rubber type (mass loaded vinyl) is the one actually deadening the cabin. The tiles with aluminum and butyl or asphalt are designed to reduce panel resonance, and the thin foam (closed cell foam) is designed to prevent interior panels from rubbing against each other, and making noise.

Edited October 1, 2012 by stefanhinote

[scampo77 0]

Does anyone knowhow to reach Don? I've tried sending him a email, Private message and links to this thread and so far no response.

[Aaron Clinton 2,372]

Email is usually the best way. He is a one man operation. I did try calling him earlier this week, but he didn't answer.

[///M5 2,833]

Wow, missed this. Your approach is interesting; however, the choice of materials is confusing...unless doctored.

To block sound (which I am sure is your problem) you need mass. Fiberglass is REALLY light. That being said it's a sticky medium that will allow you to add other things that have mass. You should also try to isolate/float this mass barrier above the surface. First step is some CLD to kill the vibe, then an isolation layer, and then your mass layer. Glassing sealing in the mass layer is interesting but perhaps not necessary. That being said if you are already part way done you are still going to need to isolate and add a mass layer if you want it to really work.

[scampo77 0]

i figured i would have to add something ontop the fiberglass. im not sure what you mean by fiberglass is light? it was 2 fold deciding on the fiberglass first i figured it would be fluid enough to squish into all places then it would dry and stay there, it could fill all the holes in the cabin this way. right now i have about 7 gallons of resin and 15kgs of glass on the floor. its not like insulation in the wall of your house its like the hull of a boat or the shell of a hut tub. if you have picked up a 5 gallon pail of waterand felt the weaight , well im at 7 gallons of resin. it is adding mass and weight and it is filling in all the holes and its giving me a nice smooth surface to put a layer on top of.

I should be done the fiberglass by this coming weekend then i need to know where to go from there. if its more mass then i still think that washed stones or silica sand locked in polyester would add more mass then anything else availible. most people sound deadening dont have the luxury of putting 6-800 lbs in their cabs without popping their tires, i do and id like to win by 20 touchdowns if i could.

I just dont want to pointless add weight. once i make polyester/stone contraption and it DOESNT work. it WONT come out. i will need a baby elephant and a jack hammer to even start, and ill probably just end up breaking all the windows out of my truck.

rubber seems like the next logical step i just need some informed opinion. i will keep waiting for Don

[///M5 2,833]

i figured i would have to add something ontop the fiberglass. im not sure what you mean by fiberglass is light?

It's got a super low weight per volume which is why it is used to build lightweight things. Strong and light. Blocking sound requires mass. Take an equivalent piece of fiberglass/resin any size you like and compare the weight to the same size as lead. Which one is light? Guess which one is the better barrier? And yes, they do sell lead sheeting which can be used AND is more effective than MLV, although in lb/$ (the only parameter that you need to pay attention to) the MLV usually wins.

I should be done the fiberglass by this coming weekend then i need to know where to go from there. if its more mass then i still think that washed stones or silica sand locked in polyester would add more mass then anything else availible. most people sound deadening dont have the luxury of putting 6-800 lbs in their cabs without popping their tires, i do and id like to win by 20 touchdowns if i could.

Think of a chain link. When you pull on the chain which one breaks? If you make a barrier that looks like swiss cheese what is the value of the barrier? You want a consistent layer anywhere that sound transmission will happen. And again as for more mass than anything available I think you need to relook at the density charts for materials. There is a reason that MLV is used or lead sheeting depending on budget. You also want to float this and having it embedded in glass won't be the best way to do this.

Rubber is not a good step. You seriously need mass, nothing else. Don will tell you the same thing as will anyone who does any sort of sound testing.

The real question is how far have you gone and what can you do to get consistent mass sheeting across the surface from this point forward. Personally until I re-evaluate I'd absolutely stop what you've started.

[scampo77 0]

NOW WE ARE GETTING SOMEWHERE!!!!

is there any health hazards to lining my truck with lead?

so what about my washed rock locked in plastic idea. how dense is stone?

is there density ratings for different types of cement?

i know a place locally to get lead sheets. it is used for lighting, i would like to try this.

[///M5 2,833]

Rock in plastic won't be homogenous which is why I gave you the chain analogy above. Sheet product is your friend. Lead or MLV are your choices.

[Impious 1,476]

IMO MLV would probably be a better option. Yes lead is more dense but depending on price you could probably layer up MLV & not have to deal with potential health hazards and it would be much easier to work with. You can find MLV in 1/4" thickness and layer it up. It will be expensive, but as M5 said mass is the only real factor here along with proper decoupling which is why I previously asked about the weight/density of the 'glass

[scampo77 0]

If i do decide to go with MLV where can i buy it from? Also how thick is it? What kind of adhesive should i use to glue it all together. i wont be able to put it down in one perfect sheet I will have to cut and fill everything then lay down a second layer.

I have got rockwool that I am using for the headliner and inside the panels. I am still not too sure what to use for the doors.

Is there any generic home products I can use that are just regular ordinary vinyl, that I can just double up?I have a few reservations about MLV.

1.) I have to buy 3 times what i need

2.) I live in Canada and this stuff from what I can tell MLV is not for sale or manufactured anywhere in Canada. The problem with very heavy sound deadening products is they are.... welll..... heavy. the problem with shipping heavy sound deadening products internationally....is....welll......................

[S.DeYoung 967]

Sounddeadenershowdown.com

[scampo77 0]

I have been waiting for 2 weeks there is no response from this guy at this website, he must be on vacation or something

[///M5 2,833]

2 weeks is an unusually long time for Don.

[edouble101 314]

I have been waiting for 2 weeks there is no response from this guy at this website, he must be on vacation or something

Resend your email. If it doesn't get responded to in a few days send it a third time. Not to make excuses for an extended delayed response time but SDS is not a full time job for Don. Being a previous customer, I can tell you that the personalized service you will receive is incomparable. You will waste your time and money looking elsewhere.

[Impious 1,476]

If i do decide to go with MLV where can i buy it from? Also how thick is it? What kind of adhesive should i use to glue it all together. i wont be able to put it down in one perfect sheet I will have to cut and fill everything then lay down a second layer.

I have got rockwool that I am using for the headliner and inside the panels. I am still not too sure what to use for the doors.

Is there any generic home products I can use that are just regular ordinary vinyl, that I can just double up?I have a few reservations about MLV.

1.) I have to buy 3 times what i need

2.) I live in Canada and this stuff from what I can tell MLV is not for sale or manufactured anywhere in Canada. The problem with very heavy sound deadening products is they are.... welll..... heavy. the problem with shipping heavy sound deadening products internationally....is....welll......................

MLV is typically sold in either 1/8" thickness (1lbs/sqft) and 1/4" thickness (2lb/sqft). For adhesive you would want HH-66 vinyl cement. I'm not sure what rockwool is, honestly, but you don't really need a mass barrier on the ceiling as there isn't much noise that penetrates through the roof.

I'm sure you can find MLV in Canada, though if there are any sources within driving distance I can't guaranty.

It's truly about mass and proper decoupling when it comes to blocking noise. You can use about anything as long as you can create a solid barrier (i.e. no gaps) of substantial mass. As I said before, 1/4" thick MLV has a mass of 2lbs/sqft. If you came up with something of equivalent mass that creates a solid barrier yes it would work the same as long as it was also properly decoupled. However, you'll have to weigh the net cost, application time and workability to determine if there is truly a better alternative. There is a reason MLV is so prevelant.....from an ease of application, mass per area, and time and cost effectiveness it's only really beat by Lead which is much more expensive and harder to work with.

Hell, on another forum there was a guy who bought a bunch of close-out aluminum foil for really cheap and wrapped it around a cardboard cutout. Net result was something that weighed ~1lbs/sqft for much less cost than MLV....but it was much thicker and how much time did he spend wrapping aluminum foil around cardboard to achieve a mass of 1lbs/sqft? I'm guessing a really, really long time.

[scampo77 0]

I don't want to bother him. it is unlikely i would buy anything from him anyway. it is just to expensive to start mailing mass loaded vinyl around especially internationally.

I am looking for more scientific answers, a better understanding of how unwanted sound moves and can be cancelled. I am also looking for more of a home brew kind of way. the fiberglass so far has made a HUGE difference in sound quality. I think that most of my problems were rust holes, holes in the firewall, and floor that went unused from the manufacturer. Now that my floor is one massive sheet of fiberglass there seems to be getting less sound/heat/vibrations through the floor.

I found a guy locally who buys all sorts of weird and unusual end of the roll vinyls. I am going down to see his warehouse tmrw he is supposed to have hundreds of different kinds of vinyl in stock, unfourtunatly he doesnt know very much about the end uses of this stuff, as he is just a buyer and reseller. I am really having a hard time knowing what i am looking for as i have nothing to compare it to, because i have never seen MLV before. I will go tmrw and try to find something that is as heavy as possible and report back!!

any suggestions for what i am looking for would be appreciated. im gueissing something very heavy, something with no foam or hair on one side (for glueing it down) and something something not transparent like net.

i will look for the glue you suggested i just have one question about urathane glue, it is the stuff used for glueing car floor pans together and mounting windshields. can i use this stuff? i have a whole case

[///M5 2,833]

I am looking for more scientific answers, a better understanding of how unwanted sound moves and can be cancelled.

It CANNOT be cancelled (well unless you play back the exact signal in perfect anti-phase), but only blocked. The ONLY thing that can block sound is mass. If you want to read up on it, look up Transmission Loss and it's theory. Of course you will learn that it is directly proportional to mass and nothing else. That being said, it doesn't matter at all what you use for mass. It will be expensive to ship since it's heavy, but finding what you can that fits the parameters of heavy per unit area is exactly all you need. That and of course complete coverage. You can imagine how a 10' thick lead wall would block all sound, but if there is a 1" diameter hole through it you sort of wasted your time making it 10' thick.

[///M5 2,833]

Oh, and yeah rockwool isn't so heavy....

[scampo77 0]

Well this is great my goal is to learn more about this, and I am.

The "mass only" argument seems to make a lot of sense and what is getting me great results so far. It is just that it adds confusion when I get different advice from different people. I called around locally and the sound studio builders all said use rockwool and so did the hardware store guy and even the bag says "sound stopper". I was trying to pack it in as tight as i can get it to add mass. It seemed to be a good fit for those hard to reach spots around the heater boxes and fire wall. If I shouldn't use rockwool inside my panels. should I use more vinyl?

[///M5 2,833]

Doesn't matter what you use as long as it isn't porous and is dense.

[Impious 1,476]

Well this is great my goal is to learn more about this, and I am.

The "mass only" argument seems to make a lot of sense and what is getting me great results so far. It is just that it adds confusion when I get different advice from different people. I called around locally and the sound studio builders all said use rockwool and so did the hardware store guy and even the bag says "sound stopper". I was trying to pack it in as tight as i can get it to add mass. It seemed to be a good fit for those hard to reach spots around the heater boxes and fire wall. If I shouldn't use rockwool inside my panels. should I use more vinyl?

Anything that has mass is technically a "sound stopper" to some degree. The question is how effectively does it block sound? For that you need to know it's mass/density. The science of it can be broken down into really simple terms; Double the mass and transmission loss increases 6db.