Hi,

Does anyone have experience with the QuietCoat sound dampening product (www.quietcoat.com)?

I'm looking for a way to reduce the sound in my 94 FD. It's been modified and is now pretty loud. I've researched Dynamat, Brownbead, Fatman, etc. but QuietCoat is the first spray on application I've found that seems to do a better job than the above.

Anyone tried it? Results? Let me know.

Thanks,

David

 

The idea behind a dampening product is to prevent the metal panel (or whatever) from vibrating. The mats are there to provide an additional layer of mass for the sound to pass through--although the application of these products will itself act as a dampening agent.

The problem I see with the spray-on dampening product is that it will likely not have a large effect on the very, very low frequencies. It should work very well on the higher frequencies. As their website points out, a large advantage of a dampening agent is that it does not require 100% coverage of the panel to work effectively.

The problem is without testing on the metal panels of the FD itself, it is very difficult to predict the effects of the treatment.

 

David, I was hoping that someone would try it and report back to us-- I really, really think that you should be that guy

 

BTW, we just received some product info from this company at work. I checked it out a little today. It looks like they do some oem work in the auto industry. Their product looks good but I don't know how it's priced compared to similar products from Kinetics Noise Control or the Soundcoat GP-1 coating.

 

I'll probably be the person to try it. I'll check out the above mentioned products and then let you know on Monday.

Should I move forward, I'll buy a sound meter to measure each stage of the project and report the results. Will start with the doors and trunk and move to the outside of the car. Should be fun!

FYI - it's about $50-60 per gallon or 5 gallons for $230ish. Reps state that 5 gallons will be plenty for the FD. Will add about 70 lbs or so though to the car but if the noise goes down, it'll be worth it IMO.

Will keep you posted.

David

 

From the product literature I reviewed, the Quiet Solutions product appeared to weigh about 1 lb/sq ft. I don't think you could cover 70 sq ft in an FD...

BTW, if you do sound readings, please do both "A" and "C" weighted readings for all your steps. I'm interested to see how much of a reduction in low frequencies you get with the damping compound.

 

The company stated that I need to use 3 coats at least. If I were to do my entire car (undercarriage, hood, wheel wells, etc.), they said to plan on about 5 gallons of the product. The rep I've spoken to (Marc) owns a 93 FD.

I'll test both readings as I too am very interested in low frequency reduction.

 

Okay, after reading many docs on the subject of sound proffing, I'm proceeding with the installation of Quiet Coat on my FD. I've ordered and received the materials from Quiet Solutions and have gone out and purchased a sound meter.

I will also take pictures and do the project in steps as to measure the results for each section of the car as I sound proof it. This may take me several weeks as I am extremely busy and will only be able to accomplish this task a bit at a time.

I'll do both A and C readings but am a bit confused as to why I should do both. Doesn't the human ear only register in the A range (or it may be only the C range, need to review the docs again)? If so, why do the C range?

Anyway, I'll keep you posted with my progress and results. Here's to a quieter car!

 

That's great David.

The difference between A and C-weighting:

A-weighting: The human ear is less sensitive to low and high frequencies. The A-weighting filter gives less importance (weight) to these frequencies when calculating a single overall sound level. Supposedly, the A-weighting matches the response to how humans actually hear. The problem is, the curve that the filter is based on is only 40 dB. At the levels that would be in your car on the highway (80 dB range), your hearing is more linear than the A-weighting filter suggests. But, the government has adopted A-weighting for noise exposure purposes, so it has become standard to use it, even for higher sound levels where it ceases to be accurate.

C-weighting: C-weighting still gives less importance to the low and high frequencies but to a much lesser degree than A-weighting. It is more accurate for how a human hears at high sound levels.

Because of the weighting, it would be possible for you to measure no improvement at all in sound levels, using the a-weighted reading. In reality, you could have lowered levels at the low frequencies by several dB, which IS certainly subjectively noticeable. Comparing the improvement with A- and C-weighted results will show in a basic way, how much the damping product reduces sound levels over the entire frequency spectrum. Ideally, you would have a Type I integrating sound level meter with 1/3-octave filters like the $6000 CEL 593 I use at work, but hey, we do what we can...

 

Thanks for the primer in A and C frequencies. You certainly know your stuff.

As for my sound meter, $50 bucks from Radio Shack. But hey, it does both A and C and it's "digital"!

I'm going to start over the weekend - will keep you posted.

David

 

David, will you be measuring after each coat

I'm only half joking-- I'm wondering whether one or two coats would make enough of a difference to save the weight from applying more coats.

 

I should know my stuff, I'm an acoustical engineer...

Hey, I have the same Rat Shack meter at my house. It's actually not terrible and will work just fine for COMPARING two sound levels.

 

Artowar - the recommended number of coats is three. I probably won't measure after each coat as I would have to put the car back together, measure, take apart, repeat. I am planning on measuring as I complete each section though (trunk, doors, hood & firewall, undercarriage).

Rynberg - assumed this from your previous post! Thanks again for the details. I can tell you whatever you want to know about healthcare software, but you've given me enough of an understanding about "sound" to complete this task.

I'm planning on starting over the weekend so look for a post early next week.

 

I'm glad you're undertaking this project. On the list of "someday" projects, I'd really like to take out the interior, do something like you're going to do, and reupholster with that ultrasuede stuff that ronkmiller sells. I need a bigger garage so that I can take it all apart and set things out for a while. If I could only afford my own hangar building...

 

i put dynamat xtreme on my doors. Some guy on ebay was selling the door kit for $25 so i grabbed it. i did a real patchy job so i can't say how well it would compare to a propper job. I only used 2 of the 4 sheets that it came with.

The doors definately sound more solid when closing. As far as sound goes, i THINK the stereo sounds a BIT louder now at the same volume. I can't say i'd recommend it unless you really want to get rid of the clanky door shut. The inside panel already seems to dampen sound (thud instead of clank when you tap on the surface). There also isn't much surface area for you to apply to. It's the outer door skin and inner middle brace that are clanky (you have to remove a plastic shield held on by tar to get to these).

I think the spray on stuff would help a lot with the outer door skin/middle brace. i'm not sure what wires you might be freezing or holes you might be filling (watch for the bottom door panel snaps if i remember right).

Good luck with the project. i can't wait to see how yours turns out.

 

Update:

Started the project this weekend. Worked on phase one which covered sound proofing the inside trunk as well as the hood.

I'm now testing the results with the sound meter I purchased and I'll post more details over the next few days. Didn't expect much from this phase. Expect much more from the doors and then from undercoating the bottom of the car.

David

 

Sweet, looking forward to the results.

 

Boost,

The doors are phse two of my project. I'm going to start this as soon as I finish posting phase I results.

Because Quiet Coat has to adhere to metal to work, I'm going to have to remove the plastic from the doors. Ohters have heated the "tar" to remove the plastic. I'm contemplating cutting out the plastic and re-gluing upon completion. Don't know yet.

Anyway, I'll try to have phase one results (including pictures) uploaded by Friday.

David

 

Update on Quiet Coat Soundproofing Project:

Phase One: Trunk and under the hood. I expect the least amount of noise reduction from this phase.

Phase Two: Doors. I expect better results from this phase.

Phase Three: Underbody. I expect the most significant gains from this phase.

I've now completed phase one of the project; sound proofing of the trunk as well as under the hood. I tackled this first because I could do this myself with a paint brush and because if I made a mistake, the results could be easily covered up! I chose to use Quiet Coat (www.quietcoat.com), a liquid, viscoelastic polymer material. The manufacturer states that unlike mats such as Dynamat and others, QuietCoat bonds to the metal in your car and absorbs sound and vibration using a new viscoelastic polymer technology. Nothing beats QuietCoat in overall overall noise reduction! Sounded good to me (pun intended)!

I removed the thermal insulation from the hood of the car (needs replacing after nine years of turbo heat abuse), and the trunk carpet, spare tire (am replacing this to save weight with a can of run flat), and the plastic access piece in the middle of the tail lights.

 

Update on Quiet Coat Soundproofing Project:

Phase One: Trunk and under the hood. I expect the least amount of noise reduction from this phase.

Phase Two: Doors. I expect better results from this phase.

Phase Three: Underbody. I expect the most significant gains from this phase.

I've now completed phase one of the project that involved sound proofing of the trunk as well as under the hood. I tackled this first because I could do this myself with a paint brush and because if I made a mistake, the results could be easily covered up! I chose to use Quiet Coat (www.quietcoat.com), a liquid, viscoelastic polymer material. The manufacturer states that unlike mats such as Dynamat and others, QuietCoat bonds to the metal in your car and absorbs sound and vibration using a new viscoelastic polymer technology. Nothing beats QuietCoat in overall overall noise reduction! Sounded good to me (pun intended!) so I ordered 5 gallons of the material as well as a spray on gun kit (it's not unique, just one that is used for undercoating of cars) - total cost, about $250 bucks.

I removed the thermal insulation from the hood of the car (needs replacing after nine years of turbo heat abuse), and the trunk carpet, spare tire (am replacing this to save weight with a can of run flat), and the plastic access piece in the middle of the tail lights. I also removed the platic trim pieces from the top lip of the hatchback as I wanted to apply the material to the metal under this area as well. Then, following the directions, I used a paint brush provided with the kit to "paint" on one coat of the material on the metal portions of the trunk, spare tire wheel well, around the rear lights, the lip of the hatchback and the hood of the car. Note that I tried my best to paint on the material on the metal between the tail lights as I theorized noise was leaking in from this area.

Applying Quiet Coat is pretty easy - it's like doing a bad job of painting as you should try to apply as thick a coat as possible (kind of the opposite of normal painting). My first mistake was probably making my coats too thin to begin with. As I painted on the second and third coats, I began to get the hang of it and made the coats thicker. Each coat needs to dry before applying the next coat so I waited about 4 hours between coats before applying the next layer. I'm in Florida so I'm assuming the material will dry much faster here than in other parts of the country. It's about 90 degrees outside and sun is no problem!. All in all, it's pretty easy. The material is water-based, so cleaning up mistakes is easy. Notice I said I "painted" the material on with a brush. I could have used the spray gun which would have made the job very easy but I didn't trust myself to not overspray the inside. I am going to use the spray gun on the undercoating phase. To avoid a problem with the material dripping on my engine, I covered the engine bay with a drop cloth. Also note I kept the plastic lip on the hatchback half way on and used the surface as a mini drop cloth to catch anything dripping from the metal of the hatchback.

Anyway, it took me two days to complete the three coats and to put everything back together. Fortunately I didn't break anything during the process.

A day after completing phase one, I used my Radio Shack sound meter to measure my initial results and I've attached these for you. As expected, the product did marginally reduce noise but not by much. Depending on my speed, the noise reduction was from 1 to 3 decibels, or from 1% to 4%.

My conclusions? Still to early to tell. I expect to get much better bang for the buck with the doors and with the undercoating portions of the project. I'm 1/2 of the way through doing the doors and from what I've seen, the results should be much more impressive. But I'll leave that up to the sound meter to decide!

Anyway, I'll update this in a few days with more pictures and the results of phase two, the doors!

David

 

Results of Phase One:

 

Anyone care to share with me how to attach pictures? I'd like to show you pictures of the above but can't seem to get it to work!

My picture are approx. 400,000 bytes each. So, what do I do?

 

Let's try again:

Picture of Quiet Coat

 

Picture of trunk prior to applying material but after carpet removal:

 

Picture of trunk lip prior to applying material. Note that I didn't remove the plastic lip totally. I kept it on to use as a built-in drip pan: