sound proofing engine compartment

[popeyefoghorn]

hi, i'm thinking about trying to deaden the engine noise, in my '78 Chris Craft Catalina Express 29'. Since its hard for any conversation while running, and you have to crank the sterio to make out any music. Has anyone had any success at doing so? I have two 1/8 thick fiberglass hatch doors and the single 305 is inches below them. thanks

 

[oops!]

Re: sound proofing engine compartment

sterio stores sell sound proofing material....

hit search.....there was a few great ideas... just a few month ago

 

[tashasdaddy]

Re: sound proofing engine compartment

foil backed foam insulation.

 

[erikgreen]

Re: sound proofing engine compartment

Plus there are some structural things you can do.

I recently got an older book that listed a bunch of good ideas... things like:

1) Make sure the hatch covers have foam bumpers all the way around to prevent rattle and seal the sound.

2) Use soundproofing insulation (obvious) all the way around the engine (including walls behind and to the sides)

3) Block the sound from going sideways using removeable walls with soundproofing on them. Block spaces between engines, and block spaces between engines and fuel tanks or water tanks

4) tanks collect and amplify sound when they are not totally full. Use insulation to isolate them from the engine

5) Use foam pads at the back of shelves and anywhere there are loose items to reduce rattles

6) Make sure your engine is properly lubricated and that the belts are good... if these are noise sources, they need replacement/work

7) Make sure after all your insulating work is done that the engine and batteries have adequate ventilation to prevent explosions.

Erik

 

[ondarvr]

Re: sound proofing engine compartment

You can get special foil backed foam with multiple layers of different density foam, plus a more solid, heavy Layer of ???. The stuff is a little pricy but works well, My buddy did his Carver with it.

 

[popeyefoghorn]

Re: sound proofing engine compartment

that all sounds good...any companies better then others or cheaper? I was wondering if there is somewhere that sells a high temp, fire proof type insulation for something other then the marine industry, that would work and be a little cheaper.

 

[erikgreen]

Re: sound proofing engine compartment

I'm planning on using dynamat extreme for mine... you can get a pack of 9 18x32 sheets for about $100-$150... more than enough for all the walls of my engine compartment/doghouse.

Deadens sound and is designed for use under the hood/over the engine (reflects heat).

Erik

 

[oops!]

Re: sound proofing engine compartment

i tried lots of stuff....

except of course most of the the things suggested here.....

the biggest problem i find with mine..is that the gunnels allow the sound thru...no positive blockage between the engine compartment and the passenger area....

i duct tapped plastic (where no one could see) in thoes areas...cut the sound in half....still too loud...used accustic celing tile...got wet..pink foam...broke...finally i did use the foil backed insulation.....it worked good on the dog house... but the sound still came thru the gunnels....i.dont want to hear the motor...(unless its knockin...then i really dont wanna hear it )

im glassing a compleate new rear cover and using dyanamat plus whetever else i can thro at it to keep it quiet.....

the best motor noise is the one that you dont hear!

 

[erikgreen]

Re: sound proofing engine compartment

the best motor noise is the one that you dont hear!

I think what you want is one of those new fangled inventions called "sail boats". They're all the rage out east