how to sound proof engine compartment??

[WINTERSUX]

I have a volvo penta 3.0, i know they are a noise engine and i am looking for a way to sound proof or at least reduces the noise. i was told to line engine compartment with egg create foam. my boat is a F/S so there is a livewell/trash can in there too. is this the best way?

 

[mr 88]

Re: how to sound proof engine compartment??

What is in there now for insulation? They do sell sound deading material specificaly for engine compartments,not cheap but effective.You should put it anywhere noise can reverberate[ like the whole transom] besides the doghouse. I would stay away from anything that can catch fire from errant heat such as egg cartons.Maybe even the foil faced 3/4" insulation they use on houses under siding would be a better option than eggy cartons and cheaper than marine deadner.

 

[DuckHunterJon]

Re: how to sound proof engine compartment??

There are several products out there that will do what you want. Peel and stick, spray on, or screw/staple on. Google Dynamat and you will start down the path. I'd be leary of anything open cell as fumes could accumulate in it. Also, some foams may break down due to the fumes. There are some mats that are felt based (think carpet pad) that might work well. Spend some time looking at what car stereo enthusiasts use to sound deaden car panels and I bet you can come up with some options.

 

[Chris1956]

Re: how to sound proof engine compartment??

There is that mylar insulation. it is light, waterproof and vaporproof and looks a lot like bubble wrap, but insulates pretty well. You might look it up to see if it is recommended for that aplication.

 

[Bondo]

Re: how to sound proof engine compartment??

Ayuh,... I did mine by dumpster diving for abunch of closed cell shipping foam sheets...
Stapled it into the motorbox, 'n lined the curtains I made to cover the other open areas...

 

[swl]

Re: how to sound proof engine compartment??

The other day I ordered some DEI "BOOM MAT" from summit, came with a free spray can of sound deadener too. Looks about the same as dynamat but a few bucks less. Puttin' it around the front and sides of the doghouse. I hate the sound of that 4 banger!! When we're out with the kids and tubing, I put the tube leaning against the doghouse, man, you can't even hear the engine! Nothing but the wind and water rushing by. If the rain ever stops, and the rivers drop, can't wait to see how it works

 

[WINTERSUX]

Re: how to sound proof engine compartment??

thanks everyone for the help

 

[Blue2Green]

Re: how to sound proof engine compartment??

I have used dynamat before but it is expensive, but works well.

 

[H20Rat]

Re: how to sound proof engine compartment??

(disclaimer, I spent many years in car audio competitions)

Dynamat is overpriced and overhyped... Its built on name first, and a second rate product. Don't get my wrong, it is still very good, just $$$$.

If you want the absolute best sound proofing, go with a layer of raamat BXT, followed by a layer of ensolite. The raamat is a mass loaded dampener (lower frequencies) and putting the layer of ensolite on top (thin layer of closed cell foam) kills the high frequencies. Both are flame retardant/proof.


http://www.raamaudio.com

 

[DuckHunterJon]

Re: how to sound proof engine compartment??

Smokingcrater is spot on - I mentioned Dynamat as it is easy to find - but there are better cheaper products out there depending on how in depth you want to take the sound proofing. I spent too many years in competition car audio, then on to a few years working acoustic testing on nuclear subs. Mass loaded damping and constrained layer damping are your best bets to soundproof the doghouse. Then again, Bondo's approach will most likely get you 95% the way there and a whole lot cheaper.

 

[H20Rat]

Re: how to sound proof engine compartment??

Then again, Bondo's approach will most likely get you 95% the way there and a whole lot cheaper.

My only thought with using random pieces of foam is that you test them with torch first to see how it reacts. It is going to burn, but it hopefully doesn't sustain the flame. (and if it goes up in a ball of flames and burns your eyebrows, bad sign!)