Killmat Sound Mat

[Nous Defions]

Took all day but got the fuel tank cover, washout plug cover and the engine compartment sound proofed. I'll reinstall the OEM sound insulation in the engine compartment and see what happens.

 

[Betik]

have the same boat, and looking forward to see what you end up doing......

 

[suke]

Interested to hear how you like the kilmat. That popped up on amazon as a possible good option. My stock sound deadening is falling off and crumbling.

 

[Hilario Perez]

Yes I will like to see how you like it cause I have to do mine before the season start back up out here un FL.

 

[Nous Defions]

Finished up today. too windy though to take her out. Happy with the way it looks, nice fit.

 

[swatski]

Finished up today. too windy though to take her out. Happy with the way it looks, nice fit.View attachment 86053

Nicely done!!!

Does the hatch close easily? Make sure there is not too much material by the hinges, those can pop.
Looks totally professional, so much better than the factory foam!

Did you add a seal? That helps a bunch.

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[Nous Defions]

Swatski, The hatch opens and closes with ease as it did before adding the Kilmat. Did not add any other seal. I have seen some add the pipe insulation around the edge. I think that might effect the hatch closing. I'll see how much this mod works first. Thanks.

 

[swatski]

Swatski, The hatch opens and closes with ease as it did before adding the Kilmat. Did not add any other seal. I have seen some add the pipe insulation around the edge. I think that might effect the hatch closing. I'll see how much this mod works first. Thanks.

This is a good seal that will not interfere - post #19 https://jetboaters.net/threads/another-soundproofing-thread-the-raamat-experience.11872/

The seal is quite critical. After that there is a couple other simple tricks that help, like this https://jetboaters.net/threads/best-and-stupid-simple-soundproofing-mod.17370/#post-299387
@Mainah did a nice writeup I can not find on insulating bulkheads.

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[Nous Defions]

What a great day out in the Indian River & Sebastian Inlet. The sound insulation worked as advertised. Extremely quite at idle but I thought it was still a little loud above idle 2-3K RPM, but after securing the gas tank cover corner that was loose, it was smooth, quite, cruising between 20-30 MPH or 6-7K RPM, the sweet spot for quite and vibration free. Above that the wind is loud enough to drown out the HO's. Not bad for about $80 worth of material from Amazon and a couple of afternoons work.

 

[Betik]

Can you please make a list of items you used ? It kind of seems that you added something else on top the killmat.

It will be nice you could prodice a general order of what you did.

 

[Nous Defions]

No problem. First I removed the OEM insulation from the engine compartment. It was in good shape so it was retained. I must add that it is high quality stuff, there is two layers of high density foam sandwiching a thick plastic sheet, then faced in aluminum. See post #5, that is the original insulation over the Kilmat.
Second, degrease all surfaces that will be covered. The materials were a box of Kilmat: $55.99, Can of spray glue: $17.88, Roller for Kilmat: $5.99 all Amazon Prime.
I had a roll of aluminum air conditioning tape that I used for the edges of the OEM insulation.

Kilmat 80 mil 36 sqft Car Sound Deadening Mat, Butyl Automotive Sound Deadener, Audio Noise Insulation and dampening

Design Engineering 010490 High-Temperature Spray Adhesive - Clear

Ogrmar Car Sound Deadener Noise Filter Application Wheel Roller (Black)

I started with the small area of the cleanout lid, since I had never done a job like this. Dry fit the kilmat and cut to size with scissors. Then peel and stick, roll out as directed and continue to the next piece. I did not cover the kill switch buttons. That was about a half hour.

Proceed to the fuel tank cover and do the same dry fit with pieces. I stayed inside the line of where the deck lip touches the cover. Mine had a foam seal on it, not sure if everyone has it. I did not want to increase the space of the seal which might make it harder to latch the cover down. To do it again I would go the edges of the cover to ensure the kilmat rest on the raised edge of the opening.

Same for the ski locker cover.

Moving to the engine compartment cover. Notice where the original insulation was and fit the kilmat in the same area. I cut out a hole for the fire access and hinge attachments. Once the kilmat was in place, I started with the small edge, back part of the cover, which is the also the lowest, to reinstall the OEM insulation. Work your way up with each piece. Spray the adhesive on the kilmat, then the back of the OEM insulation. You don't have to work fast, but don't screw around. Also with the adhesive, where you attach the two pieces is where they stick there is no pulling apart and realigning, so dry fit everything to see where things line up before gluing. I layed a sheet over the engines and worked/sprayed in the engine compartment.

One can did the engine compartment with nothing to spare.

Only the engine compartment got the OEM insulation over the kilmat.

Can easily be done in a day with help or a weekend solo with many beer breaks.

Hope it lasts another 9 years!

 

[suke]

Isn't the killmat peel and stick? What did you use the spray adhesive for? 36 sq ft was also enough? That seems small.

 

[Betik]

Thank you much appreciated

 

[Nous Defions]

I guess it wasn't clear in my write up. Once the kilmat is up, it is peel and stick, use the adhesive on the kilmat to reattach the OEM insulation. Each kilmat is approx 36 sq'. I bought two boxes because everything I wanted to do measured out to approx 70 sq'. I only used one box of kilmat to do everything. Now I might go back and do underneath the seat cushions and the back of the engine compartment, but I'm happy with the results so far. I have an 1987 Chevy Square that could use the extra kilmat.

 

[swatski]

I guess it wasn't clear in my write up. Once the kilmat is up, it is peel and stick, use the adhesive on the kilmat to reattach the OEM insulation. Each kilmat is approx 36 sq'. I bought two boxes because everything I wanted to do measured out to approx 70 sq'. I only used one box of kilmat to do everything. Now I might go back and do underneath the seat cushions and the back of the engine compartment, but I'm happy with the results so far. I have an 1987 Chevy Square that could use the extra kilmat.

Thanks for the write up, the price on this Killmat is crazy good, that is about 10 times less than Dynamat Extreme... I bet works the same! and it is butyl rubber, not tar as some cheapo alternative roofing products.

That said, I really thing that, in addition to all the surface sound deadening and sealing gaps, filling in the empty resonator-like spaces in the hull is necessary to quiet this beast, as the driveline and pump ride about the water and all the vibration just resonates like crazy throughout the hull. It is a perfect big resonator box built of thin, rigid FRP!

I have filled appprox 20-25 cans worth of polyurethane foam inside the enclosed hull panels and and stuffed the bulk of empty spaces with memory foam, pillow-type products, and I can finally stand it. Before that I felt like I was going to lose my hearing in short order riding this thing...

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[suke]

I guess it wasn't clear in my write up. Once the kilmat is up, it is peel and stick, use the adhesive on the kilmat to reattach the OEM insulation. Each kilmat is approx 36 sq'. I bought two boxes because everything I wanted to do measured out to approx 70 sq'. I only used one box of kilmat to do everything. Now I might go back and do underneath the seat cushions and the back of the engine compartment, but I'm happy with the results so far. I have an 1987 Chevy Square that could use the extra kilmat.

That's what I thought, but it wasn't totally clear to me. Yeah I need to do some sound deadening work in my jeep. So I'll buy 2 boxes and what's left put it in my floor board in the my jeep.

 

[Shookie]

Just put some of this Kilmat in the Amazon cart.... no idea on how much I'll need, but I'm thinking I'll start with 2 boxes for my 242. Engine compartment/door, rear storage, gas tank, etc.

@swatski - Do you have any guide as to where you are blowing in all that foam? Worried about any areas getting wet and retaining water? Not sure if would do that but that's the conservative (don't F something up) voice in my head.....

 

[swatski]

Just put some of this Kilmat in the Amazon cart.... no idea on how much I'll need, but I'm thinking I'll start with 2 boxes for my 242. Engine compartment/door, rear storage, gas tank, etc.

@swatski - Do you have any guide as to where you are blowing in all that foam? Worried about any areas getting wet and retaining water? Not sure if would do that but that's the conservative (don't F something up) voice in my head.....

Mostly up - behind the side panels and under the hull cap, especially the bow. Removable foam panels in the bilge. It is a major PIA/labor, but it works.
https://jetboaters.net/threads/fill...ng-foam-good-idea-bad-idea.17966/#post-309944

Also, this:
https://jetboaters.net/threads/best-and-stupid-simple-soundproofing-mod.17370/#post-299290

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[Scottie]

Maybe I'm misunderstanding. What's the final layer that is visible in the picture? My OEM insulation looks nothing like that, and is certainly not what I would call high quality.

 

[Nous Defions]

Scottie, mine is a 2010, not sure if everyone has the same stuff. Don't think the guy I bought the boat from added it but it's possible.