What is the best sound deadening product

[Bruce]

I plan to replace the foam on the engine cover and add sound deadening to newly installed plywood separating the engine compartment from the under seat storage and seat backs.

I am considering this Dynamat product
http://www.amazon.com/gp/aw/cr/B00020CB2S/ref=mw_dp_cr but I do not have any experience in this area and would appreciate your advice.

Thanks

 

[txav8r]

I just wanted to actually get to a post that had zero responses...I don't know anything about the sound deadening but read that the dynamat is good stuff!

 

[Murf'n'surf]

I used the sound deadening foam sheets sold at West Marine on my engine cover and forward bulk head. I can't find the link right now but I can tell you that I found minimal reduction in noise. It seems that in our Classic boats the noise resonates through the hull/bilges. These voids need to be foam filled!
http://www.westmarine.com/putties-sealers/evercoat--two-part-pour-foam-kit-2-quarts--314080

 

[Bruce]

I just filled a big one





Now I need to apply a sound deadening product.

 

[Murf'n'surf]

Very nice! I think that foam sheeting would work just as good as anything.

 

[steined]

I'd try that stuff that Ronnie on the other forum bought from McMaster Carr or maybe the West Marine foil/foam/rubber stuff. I don't think dynamat is what you are looking for in reducing sound in a boat. The stuff I bought (acoustiblok) requires more thorough installation than I've had time to do. It made a difference, but just on the engine cover it wasn't worth it in my opinion. It helped, but the work wasn't worth it.

 

[Bruce]

I have installed plywood on both sides blocking the under seat storage and the channel behind the seats from the engine bay. If I add sound deadening to the plywood, the hood and behind the fuel tank I should be covering most of the area where the sound can come foreward.

 

[cbus]

Every thread about sound deadening is similar.

Everyone experiences something different - so very subjective!

I installed Dynamat last year and to my very untrained ear, I noticed a marked improvement especially at low speeds. My family noticed it as well. We can hold conversations without raising our voices as much.

I applied to the engine bay then reapplied the original material over that. I also did the lid to the gas chamber.

Overall, I'm pleased and don't regret the small investment of money and time.

 

[jetboater4life]

I bought some dynamat and some fatmat and will be comparing and then installing the two materials in my engine compartment and on the under side of my fuel tank cover. I'll take some pics when I get them out of the box, not sure when that will be though. (Coaching soccer ends this weekend so maybe).
I also bought some pipe insulation for my engine hatch seal. I think it's the same stuff that @Ronnie just installed.

 

[JC6275]

IMHO, I would say the best sound deadening product is..........wait for it........
The one that deadens the most sound!!!!!
I'm sorry I had to, it was calling me every time I saw the title. PLEASE DONT BAN ME FOR BEING A SMARTASS!!!!

 

[MikeyL]

IMHO, I would say the best sound deadening product is..........wait for it........
The one that deadens the most sound!!!!!
I'm sorry I had to, it was calling me every time I saw the title. PLEASE DONT BAN ME FOR BEING A SMARTASS!!!!

I am in total agreement.
I am VERY particular to a somewhat more expensive product made by SecondSkin.
http://store.secondskinaudio.com/
It is called DeAmplifier Pro.
http://store.secondskinaudio.com/damplifier-pro/

In Sound deadenng products, as many of y'll already know there are 3 things going on:
A) The industry is FILLED with a ton of hocus-pocus buzzwords, and TOTAL OUTRIGHT lies.
B) The industry in many cases goes to EXTREME lengths to cause confusion in buyers.
C) In general , you get what you pay for.

Please keep in mind, some of the products peope "talk about" on boating forums are nothing more than ROOFING MATERIALS ! Sold at exhorbitant prices as well. Watch out for sound deadening stuff sold on eBAY - Most falls into this category. Filled with Asbestos ! And the resultant smell.

Summary: Dynamat is a great product, a LOT of people use. Check out Amazon for great pricing on this. DeAmplifier Pro is THICKER (ie, again, this translates into more $ cost - And a QUIETER resultant sound level) and with a THICKER metal backing (ie, again, more $ cost). The company's website explains all of this if you wanna check it out.

Our boats have NO PROBLEM withstanding the additional weight of DeAmplifier Pro.

We should add three additional points.

1) GOOD PRODUCTS - Like Dynamat and DeAmplifier Pro DO WORK ! Ya cannot "fix" inherent built-in (ie, read poor engineering design) noise related problems by Yamaha engineers - But you CAN make them TOLERABLE !

2) INSTALLATION - PROPER INSTALLATION - will also determine exactly "how" successful you will wind up being.

3) The HEAVIER the sheet of sound absorbing material weighs, the MORE it DEADENDS sounds. Period ! (Ie, Watch out for more hocus pocus here, where far LIGHTER products (read "CHEAPER TO MAKE !") are advertised as being superior in sound deadening properties.)

In this regard, the material MUST BE ROLLED - hopefully on a WARM day - and using a quality PRESSURE ROLLER. You will hear all kinds of (ie, again read INACCURATE) hoopla about this on this forum, and other websites, about how you can do this installation with simply your hands, or using a tennis ball. All of that is HOOPLA. Spend the bucks and get a good roller. I have attached a link of 1 I use and am glad I purchased. It rolls on INTERNAL BEARINGS. These are referred to as "SEAM ROLLERS."
http://www.shagtools.com/tools/Crain-Round-Edge-Seam-Roller-05-349S.cfm?Partner=Froogle05-349S

There is nothing better than to PRESSURE ROLL on the material and get rid of any trapped air pockets. Once you own this seam roller and are using it, you will at THAT point appreciate why you spent the additional $$$.

LASTLY: A Sound Deadening material "Kit" of 36 or so square feet is more than enough to do all you (normally) will ever wind up doing with our boats.

Good Luck and If I can help any further, please contact me.
Sincere Best Wishes, Mikey Lulejian - Lake Oconee, GA

 

[Ronnie]

I've got more detail or will have more detail in my 2014 upgrades post but I just completed my sound deadening project so this is all very fresh.

What: 17 linear feet (1' x 4.5') of 1" thick peel and stick fire and water resistant foam with a reinforced foil / reflective face and a roll of foil tape.
Where: Replaced all hatch material (and added a little back), surrounded the engine compartment from the level of the engine mounts creating a dome like cover over both engines. Also put on the bottom of the fuel tank cover and part of the compartment.
Time: About 20 hours
Cost: Around $400
Tests: via a decibel app on an iPhone 4s with: a) no insulation at all, b) just the hatch and bulb seal (on the water and trailer), c) after the project completed.

I don't know if it is going to work but my usual crew and I thought it worked well on the Yamaha SX230 HO I used to have and the engines in my 242 only rev to 8K instead of 10K, so I am expecting at least similar results.

Here are some fresh pics.

@Bruce , I think we are of the same mind on this. That is, try and isolate the engine sound/noise to somewhere other than the cockpit. I've stated this before but I'll never do this again myself. If I could afford to pay someone that I trust doing it I would.

 

[txav8r]

I have to say @Ronnie , that is a remarkably clean and professional looking install. There is no way I could do that install. You had to have removed 30 hoses to get into some of those places. I am guessing yours is MUCH quieter after that. In all of your pics, I can only make out one area that I even see seams in. Very nice work.

 

[Chillypilot]

I'm putting both soundown and roadkill stinger (similar to dynamat) in my boat. Roadkill helps reduce vibrations soundown absorbs and blocks sound. I'm half done my project and can already notice quite a difference. @Ronnie fantastic job with yours can't wait to hear or should I say not hear your results.

http://www.soundown.com/Section 2 PDFs/2.1 PDFs/Vinyl Foam.pdf

 

[Glassman]

I used the sound deadening foam sheets sold at West Marine on my engine cover and forward bulk head. I can't find the link right now but I can tell you that I found minimal reduction in noise. It seems that in our Classic boats the noise resonates through the hull/bilges. These voids need to be foam filled!
http://www.westmarine.com/putties-sealers/evercoat--two-part-pour-foam-kit-2-quarts--314080

I used two of the 1" thick sheets and had pretty good results considering I didn't go as far as I had planned. I had plans to seal off the compartments, never got around to it. I used my wife's ear to measure the difference in before and after results. Once she said it was good, I stopped and we went boating!

Link:

http://www.westmarine.com/west-marine--noise-control-barrier-material--P006_180_006_004

I like that it is made specifically for installation in engine compartments. Most, if not all, of the typical audiophile type noise suppression material isn't.

I have used a variety of different products in different vehicles over the years.

The best was when I did the install in my van. Not only did I have to overcome road noise and vibration - Dynamat for the doors and vertical surfaces.
I had to contend with the exhaust note from the Banks system I have installed. For that I poured 5 lb. density liquid urethane on the entire floor of the vehicle (after pulling up all of the OEM insulation and carpet) That chit is excellent, unfortunately for you guys you'd have to buy a drum to get the same stuff I use here at the factory.

 

[Ronnie]

It looks like I used very similar material to that west marine sells. The only better IMHO is the same thing but all glued to a him layer of plastic (I couldn't find any this time around). On a related note west marine's offering is very over priced, if I read it correctly the cost is over $42 per linear foot. And the tape cost is even more inflated.

 

[Glassman]

It looks like I used very similar material to that west marine sells. The only better IMHO is the same thing but all glued to a him layer of plastic (I couldn't find any this time around). On a related note west marine's offering is very over priced, if I read it correctly the cost is over $42 per linear foot. And the tape cost is even more inflated.

Yes, the West Marine product is pricey at retail, but it's reasonable with my Port Supply discount. I used very little, if any, tape.



With the OEM stuff placed over the West Marine product there is a fair amount of insulation.

I'm satisfied with the results. At idle I often have to check to make sure both engines are running, that's plenty quiet for me. When running the wind noise overwhelms everything - that's what going fast is all about. I'm used to it. Driving a convertible does that to you I guess.

 

[txav8r]

I am wondering as you speak, @Glassman , as I get to speed, it really doesn't matter what noise the engines make because I can't hear much in the WIND! Which brings up the thought, why don't we just wear headphones!

 

[Glassman]

I thought about that too! We have car to car radios with headsets/helmet speakers and handhelds + helmet speakers for the bikes in the desert and they are just great.

I almost grabbed a couple of handhelds and headphones from the toyhauler to use on the boat this last trip. I should get my buddy to bring his along as well. The only difference is that in the desert we use them to keep from losing each other in the dust.
When boating there's no dust and one long river, so it's hard to lose anyone...would be good for coordinating meeting up for breakfast though

 

[Chillypilot]

I have found sounddown 1" thick (same thing as what West Marine sells) for 89.00/ sheet 27sq/ft. You can probably do better in the US. Soundown is very heavy so if top speed is a consideration it might not be a good option.