Sound Deadening Mercury 1500

[Zac Penn]

Now that I slowly getting the kinks worked out of my motor I am trying to make my boat a more enjoyable environment for my buddies. Currently you have to yell to one another if you at anything over idle. Seriously YELL if it is over 3000 rpm. I also have two seats in the back of the boat that i would like for people to use, but if we are running they will actually damage their ears if they sit there.

The THIN sheet metal cowling has some old plastic wrapped fiberglass stuff inside of it but it isn't really helping at all. The cowling is a three piece unit so it will never be as quiet as the newer one piece cowlings but I don't want to waste the money on sound deadening material if other have tried this and failed.

Thanks,
Zac

 

[Chris1956]

You can try some Mylar insulation. It looks like silver bubble wrap. It should help some. Those motors were never really loud. Any chance you have some sort of exhaust leak, making that noise?

 

[Zac Penn]

I mean no disrespect but your idea of a loud outboard must be different than mine. It doesn't sound like an exhaust leak, even though the upper exhaust port is above the water level, just a lot of engine noise. The motor sounds healthy with no alarming noises however there is a high pitched noise that i can't really describe and I doubt would be audible with a video. It doesn't sound like a bad noise just different to me. This is my first outboard motor of any real size so i don't have much to compare it to other than my friends 4 stroke motors that are basically silent compared to the tower of power.

I will tinker around with a few things and see if it helps.

 

[gm280]

I've seen what looks like padded material type sound deadening on OB cowls before. It looked like somebody took some foam (or whatever, I really don't know for sure) material and sewed it inside the vinyl covering and attached it to the inside of the cowling... Just an idea. I honestly don't know if that would even help. They do make a material for inside vehicle doors to sound deaden vehicles. You could look into the stuff... :noidea:

 

[Scott Danforth]

Here is what I have used in a prior work life as well as my current work life

http://soundown.com/Section 2 PDFs/2.1 PDFs/Acoustic Absorp Foam.pdf

Sold right here on Iboats http://www.iboats.com/Soundown-Acou...605096--session_id.484438900--view_id.1185864

 

[emckelvy]

Dynamat works great for sound-deadening but is quite expensive. Home Depot/Lowes sell a roofing patch material that's sticky tar-based on one side and foil on the other, the only drawback in using it in auto applications is it tends to smell for a while.

That wouldn't matter in an outboard! It's a lot cheaper than Dynamat.

If you lined the wrap-around cowling with it, and applied some to the upper "top hat" engine cover, I bet it would make quite a difference.

HTH...........ed

 

[Zac Penn]

Thanks for the money saving suggestion. I will swing by and check it out.

 

[emckelvy]

Here's a little info, the stuff is called "Protecto Wrap" and there are various types of sticky products listed at the Home Depot website.

I found this which I think is what they were using, it's got the sticky backing, and foam on the other side; should be perfect for sound dampening. 1/4" thick, the sticky part adds mass to the noisy cowling and will dampen vibrations, and hopefully the bit of foam adds to the sound-deadening qualities:

http://www.homedepot.com/p/Protecto...ld-Tape-5007257/205893013#product_description