Sound Deadening Project - 2011 242

[Nightmare]

This is hopefully the final big project for this boat and then I can just chill.
One of the first things I noticed when we looked at this boat was that the Engine Cover was missing a bunch of foam insulation.
On the first trip on the water, my wife commented on how loud the boat seemed. So I started looking for articles, and there are several.

I decided to buy:
Kilmat (https://www.amazon.com/gp/product/B0751CBXBT/ref=ppx_yo_dt_b_asin_title_o03_s02?ie=UTF8&psc=1)
and
Acoustic Foam Panels (https://www.amazon.com/gp/product/B0866CCQVM/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1)

I'm going to take the cover off the boat as suggested somewhere else. I'll remove what is left of the factory foam and Kilmat the whole cover. Then glue the foam over the top. I'll probably re-use the back piece.


I'm going to see if I can get back to the rear of the engine compartment with the Kilmat. I might put the foam over the top.


For the sides, I might just glue the Foam over the carpet. I don't want to rip out the carpet and pull all those screws.
I think I might cut some 3" Strips and run it along the Gelcoat under the carpeted area.


My boat still has the Fresh Water tank. I'll wedge a couple of foam blocks between the tank and the walls/Ceiling.
Since the carpet next to the Ice Chest is already loose. I'll probably stick some Kilmat under there. I assume the same glue I use on the foam will stick the carpet back.


My Batteries are pretty far forward. So I might just put 6+ foam blocks in the back corner. Someone posted that storing a towable tube back in that corner really soaked up a lot of sound/reverberations.


Removing the carpet on the sidewall and/or installing some Kilmat on the roof of these compartments is also an option.


And the easiest part should be the door for the gas tank. I'll just pull it off and Kilmat the whole thing.

I took some sounds measurements on the lake Tuesday. I picked up an $18 DB Meter on Amazon and I used the free App on my iPhone12. I'll post the before and after numbers once I get it all wrapped up.

If anyone has some tips/advice, let me know.

 

[TJP027]

Would love to see the finished product.

Researching this myself

Thanks

 

[tdonoughue]

When removing the factory foam: wear gloves and/or use a scraper.

Ask me how I know how painful it can be if you are trying to remove with your bare hands and catch one of those fiberglass splinters under your nails...

 

[Nightmare]

The factory foam is pulling off with the slightest effort, but I'll watch out for the fibers.

I tried to remove the Engine Cover and it is too heavy/awkward to do solo.

I pulled out the Gas Tank Cover and got it covered in about 40 minutes. This Kilmat is going to be a nightmare for anyone with actual OCD. Nothing lines up, nothing lays down evenly...

10.5 Sheets

 

[tdonoughue]

Hint from one of the writeups here: You don't need to cover every square inch. If you get that Kilmat on 90% of the surface, you are doing good and will probably see no difference for the last (and most difficult) 10%. So on my gas hatch I used some of the remnants from the engine hatch to fill in that middle part between the reinforcements.

Oh, and don't worry about taking off the engine hatch. I left mine on when I did mine. I lived.

 

[Nightmare]

WHY is there so much dirt under this back seat? And this is after I wiped up most of it.


I spent about 45 minutes cleaning up the hatch. Scraping off the foam, cleaning up some of the glue and roughing up the slick fiberglass.


This took 1.5 hours. Not too bad. I might cut a couple more little strips to fill the gaps.

 

[adrianp89]

You need MLV under the foam

 

[Babin Farms]

I would remove all the nuts and washers when you do the back side of the engine bay so that your seats will still be removable after you put the kill mat down

 

[Nightmare]

I'm using the Kilmat instead of MLV. I didn't want to deal with trying to stick down the rolls of MLV.
I did remove all the seat nuts. I'll cut holes in the Kilmat and the Foam so they can be accessed.
I just spent 3 hours drive all over town looking for stupid parts that are hard to find due to Covid.
And my Bimini top that the previous owner ordered in December 2020 won't arrive until after the 4th of July...

 

[tdonoughue]

Never say die: Amazon.com: 2-Pack Nautica Umbrella for Travel - Auto Open Compact, Lightweight & Folding - Best Windproof Umbrellas for Rain, Sun & Wind Protection, Small, Automatic & Collapsible in Black: Clothing

 

[Nightmare]

That is only slightly more embarrassing than my current solution:

 

[adrianp89]

I'm using the Kilmat instead of MLV. I didn't want to deal with trying to stick down the rolls of MLV.
I did remove all the seat nuts. I'll cut holes in the Kilmat and the Foam so they can be accessed.
I just spent 3 hours drive all over town looking for stupid parts that are hard to find due to Covid.
And my Bimini top that the previous owner ordered in December 2020 won't arrive until after the 4th of July...

Kilmat will be relatively ineffective on the fiberglass. Sure it adds mass but the fiberglass doesn’t really resonate. MLV is 100% different and works in conjunction with deadener and foam. While all three are needed for complete deadening, MLV is the most effective at removing sound (that’s why it’s heavy and expensive)

 

[Nightmare]

Kilmat will be relatively ineffective on the fiberglass. Sure it adds mass but the fiberglass doesn’t really resonate. MLV is 100% different and works in conjunction with deadener and foam. While all three are needed for complete deadening, MLV is the most effective at removing sound (that’s why it’s heavy and expensive)

Have you done the MLV on your boat? Do you have a product to recommend?

This seems like one of the least expensive Self Stick MLV products:

SilentWrap™ Mass Loaded Vinyl PSA | Sound Acoustic Solutions

Mass loaded Vinyl PSA efficiently isolate sound or reduce noise issues for commercial and residential walls with a pressure sensitive backing.

www.soundacousticsolutions.com

 

[Nightmare]

I got the Engine Cover done. I planned to leave the seat nuts exposed, but the threads were just too short. Hopefully, I don't need to pull the seats any time soon. I can feel the location, so if necessary I can cut holes in the foam.

 

[four_the_kids]

That is only slightly more embarrassing than my current solution:
View attachment 152393

Here's an alternative to consider, we use one when anchored to extend our bimini from time to time. Naturally it's not recommended for use above slow speeds; Anchorshade III | Taylor Made

 

[Nightmare]

Thanks for that link. I think we will want something to cover the rear seats. I wasn't sure what would be easy to set up and take down.
$160 is a little pricey, but the 2-3 Week Delivery is not great.

 

[adrianp89]

Have you done the MLV on your boat? Do you have a product to recommend?

This seems like one of the least expensive Self Stick MLV products:

SilentWrap™ Mass Loaded Vinyl PSA | Sound Acoustic Solutions

Mass loaded Vinyl PSA efficiently isolate sound or reduce noise issues for commercial and residential walls with a pressure sensitive backing.

www.soundacousticsolutions.com

No, my new boat is relatively quiet so not too much of a concern. I have done several cars. I 100% would not do MLV peel and stick. It is much too heavy to last.

 

[Yogi72]

I got the Engine Cover done. I planned to leave the seat nuts exposed, but the threads were just too short. Hopefully, I don't need to pull the seats any time soon. I can feel the location, so if necessary I can cut holes in the foam.
View attachment 152711

Did you use a spray adhesive to secure the foam panels?

 

[Nightmare]

Yes, Gorilla brand because apparently Covid has screwed up glue supplies
No 3M or Loctite available anywhere

 

[Nightmare]

We went to 2 different lakes in the last couple of weeks for a total of 8 days on the water.
The foam does seem to help with the sound. I planned to used the DB meter and the phone to check levels, but I didn't get that accomplished.

We went over 100 miles, used a FULL 51 gallons of gas in 3 days (the fuel low came on in the last evening, I made it to the ramp and filled up on land). For the final 5 days we mostly just sat in the cove and watched the scenery.

I noticed the foam peeling off in a couple of spots during the trip and when got home I found that 2 full blocks just fell off.

The Kilmat is still a little tacky, I think I just need a better bond to the foam. I'm not sure if 3M would hold any better or if I need something with more mass like liquid nails. Here is a pic of the hatch.