Sound Proofing

[Norboo]

Past Sat, I took my boat out of storage after the long winter. When I opened the engine hatch, I noticed the foam covers was coming undone in some places. I am guessing I didn’t stray enough on certain parts since other places are holding well.

So, spray/cover your 3M 77 thoroughly before reattaching your foam cover.

 

[Jim Robeson]

For all you folks that are thinking about using Spray 77, and I thank you for that, there are better 3M products for your applications. I work with just about every spray adhesive that we make and 77 is a good industrial spray but not the best for foam. I am adding a web address that might help you with future projects like this one if you're interested. If you still have any questions, please don't hesitate to send me an email...jmrobeson@mmm.com...as I work with marine sealants, contact adhesives, aerospace two part products, and spray adhesives.

http://multimedia.3m.com/mws/mediawebserver?mwsId=66666UgxGCuNyXTtn8TVNXT_EVtQEcuZgVs6EVs6E666666--&fn=78-9236-7223-8-HR.pdf

 

[Norboo]

For all you folks that are thinking about using Spray 77, and I thank you for that, there are better 3M products for your applications. I work with just about every spray adhesive that we make and 77 is a good industrial spray but not the best for foam. I am adding a web address that might help you with future projects like this one if you're interested. If you still have any questions, please don't hesitate to send me an email...jmrobeson@mmm.com...as I work with marine sealants, contact adhesives, aerospace two part products, and spray adhesives.

http://multimedia.3m.com/mws/mediawebserver?mwsId=66666UgxGCuNyXTtn8TVNXT_EVtQEcuZgVs6EVs6E666666--&fn=78-9236-7223-8-HR.pdf

What would you recommend for bonding foam and Dynamat? Thank you
http://www.amazon.com/Dynamat-10455-Self-Adhesive-Deadener-Xtreme/dp/B00020CB2S/ref=cm_cr_pr_product_top

 

[Jim Robeson]

If it's foam on one side and you are adhering to foam I would use Spray 74. It's what they call a lace spray and you can set the width of your spray pattern according the coverage area you desire. This product is also created to bond foam to foam with a better heat resistance than 77. With that being said, I've never worked with Dynamat so I'm just taking an educated guess.

 

[Norboo]

If it's foam on one side and you are adhering to foam I would use Spray 74. It's what they call a lace spray and you can set the width of your spray pattern according the coverage area you desire. This product is also created to bond foam to foam with a better heat resistance than 77. With that being said, I've never worked with Dynamat so I'm just taking an educated guess.

Dynamat is more of foil covering.

 

[Jim Robeson]

@Norboo ... let me do a little research and give you a better answer. Just to be clear, you're bonding a foil backed product to foam?

 

[Evil Sports]

Im interested in some of those holes people have mentioned going from the engine compartment to the fuel area. Is that a significant source of the noise??

 

[Jim Robeson]

@Norboo ... I think I would go with Spray 90 ... http://solutions.3m.com/wps/portal/3M/en_US/Adhesives/Tapes/Products/~/3M-Hi-Strength-90-Spray-Adhesive?N=5396314+3294310566&rt=rud .... This product has some nice properties, and bonds well with metal to foam or foam to foam. Chances are you can order from Grainger or maybe even 3M ... http://www.shop3m.com/3m-hi-strength-90-spray-adhesive-clear-24-fl-oz.html?WT.ac=WTB_US_62494249501&psrid=47588871

 

[Norboo]

@Norboo ... let me do a little research and give you a better answer. Just to be clear, you're bonding a foil backed product to foam?

Yes.

 

[Jim Robeson]

@Norboo ... sorry I didn't cover this in one post. If you can wipe down the foil with some alcohol and let that dry before you spray the Dynamat, that would help. And make sure and spray both substrates, foil and foam, with product before you make your bond. This will give you a better bond line and better results.

 

[Norboo]

Im interested in some of those holes people have mentioned going from the engine compartment to the fuel area. Is that a significant source of the noise??

My guess would be the floor gives off more noise than the “holes”.

 

[Norboo]

Got it at Home Depot today. Plan on using it this Sunday.

 

[Jim Robeson]

@Norboo ... hope it does the trick for you!! Send me a message if you have any questions or get hung up on something.

 

[BoaterGuy]

I was at the gym and did some push ups on the rubber gym mat while using my iPhone and Bluetooth headset. My phone was in my shorts pocket and the connection would cut out when my phone got close to the mat.

Had me thinking... That rubber mat is pretty thick and could be a great sound isolator. It certainly absorbed my Bluetooth signal pretty well. Different kind of wave, but still interesting.

The mat material seems pretty cheap in comparison to the other sound deadeners out there? Might be a little heavy but for the floor pieces that shouldn't matter to much.

Thoughts?

This is the stuff:
http://www.amazon.com/gp/aw/d/B007SWPD4Q/ref=mp_s_a_1_6?qid=1396041293&sr=8-6&pi=AC_SX110_SY165_QL70

There is 3/8 too:
http://www.amazon.com/gp/aw/d/B003BS2RUE/ref=pd_aw_sbs_5?pi=SS115#

 

[Jim Robeson]

Just something else to ponder...our engines produce a certain sound wave that you're trying to muffle or insulate. What if you could produce a sound wave that would cancel out the engine sound?? It's called Active Noise Control. Basically you add a sound wave that is opposite of the sound wave that is being produced. The result is a neutral sound. We talked about something like this in our plant some time ago but everyone thought it would cheaper to just make everyone wear earmuffs or earplugs. And it probably was. Anyway, if one of smart folks out there could come up with a speaker that emits the opposite sound wave we would never need to add any sound deadening to our boats. Just something for you more intelligent minds out there.

http://en.wikipedia.org/wiki/Active_noise_control

 

[jetboater4life]

It's an interesting idea but the sound would have to change at the RPM's change making it slightly more complicated.

 

[tdonoughue]

Actually, I don't think that is the challenge. They make headphones with noise cancellation this way and have for years. You use a microphone and take that signal and put it out of phase and pump that out the speaker. It works in headphones because they are able to generate that out of phase signal close to and the same direction (well, 180 deg from) as the microphone.

Our challenge would be that the listeners will be at different distances and directions from two sources. You would need to put two omnidirectional drivers right on top of the source, big enough to be louder than the engines. Any other location and for some people on the boat the out of phase would become in phase... Thus making it twice as loud.

 

[Ronnie]

WOW! I want you to design my sound system when the time comes. I'm guessing you are an inventor/patent attorney/engineer.

I was thinking if it were that easy why stop at boats? You could make million$ applying the tech elsewhere (e.g. Automotive, aeronautics, uh military).

 

[tdonoughue]

Good guess... Patent attorney. Know a little bit about a lot of things...

 

[Magic]

I was at the gym and did some push ups on the rubber gym mat while using my iPhone and Bluetooth headset. My phone was in my shorts pocket and the connection would cut out when my phone got close to the mat.

Had me thinking... That rubber mat is pretty thick and could be a great sound isolator. It certainly absorbed my Bluetooth signal pretty well. Different kind of wave, but still interesting.

The mat material seems pretty cheap in comparison to the other sound deadeners out there? Might be a little heavy but for the floor pieces that shouldn't matter to much.

Thoughts?

This is the stuff:
http://www.amazon.com/gp/aw/d/B007SWPD4Q/ref=mp_s_a_1_6?qid=1396041293&sr=8-6&pi=AC_SX110_SY165_QL70

There is 3/8 too:
http://www.amazon.com/gp/aw/d/B003BS2RUE/ref=pd_aw_sbs_5?pi=SS115#

Very interesting idea........