My Acoustiblok Install

[Evil Sports]

He didnt say insignificant results, I did. Reason being people have been posting sound mods for years and I have yet to see one where the people said it was a major difference. I hope all that work he did proves me wrong as I want to quiet down my boat too.

 

[Chillypilot]

Just did my fuel hatch tonight with Stinger Roadkill. It's a self adhesive foil backed butyl rubber. Was pretty easy to apply. Just cut, peal, and stick. Took about 45 minutes. Feels/sounds much more solid now.

 

[Ronnie]

I'm about to install some sound deadening material on my fuel tank cover as well but am already wondering what, if any, reduction in sound this will lead to. The reason I'm questioning it is that if I insulate the entire engine compartment I should be keep sound from getting to the fuel tank compartment so what's the purpose of insulating that as well? Maybe to keep the hatch from vibrating, not sure but at $17 per 1 ft x 4.5 ft piece this is looking like a $68 to $85 Experiment (including the bulkheads in the fuel tank compartment). Given the costs and without baseline readings I will probably just convince myself that it helped. At least the install in this area is easy.

 

[Evil Sports]

Ronnie, here is a inexpensive alternative,

http://www.frostking.com/foil-and-fiberglass-duct-wrap/

 

[Ronnie]

Thanks Evil but I already bought 17 linear feet of material from McMaster Carr it is similar to the stuff used by Searay in its quiet ride technology system so I hope it will produce the same or similar results in my boat. Still I may use the duct insulation on the underside of the hatches like I did on my previous boat, it looks very similar to megamat but can probably be purchased for a lot less at a hardware store like Home Depot.

 

[steined]

I'm about to install some sound deadening material on my fuel tank cover as well but am already wondering what, if any, reduction in sound this will lead to. The reason I'm questioning it is that if I insulate the entire engine compartment I should be keep sound from getting to the fuel tank compartment so what's the purpose of insulating that as well? Maybe to keep the hatch from vibrating, not sure but at $17 per 1 ft x 4.5 ft piece this is looking like a $68 to $85 Experiment (including the bulkheads in the fuel tank compartment). Given the costs and without baseline readings I will probably just convince myself that it helped. At least the install in this area is easy.

You are correct, if you get the entire engine compartment sealed, no need to do fuel hatch most likely. But I decided to take the path of least resistance and do the hatch instead of farting around with removing air boxes and the like to do that wall in the engine compartment.

 

[Chillypilot]

I'm about to install some sound deadening material on my fuel tank cover as well but am already wondering what, if any, reduction in sound this will lead to. The reason I'm questioning it is that if I insulate the entire engine compartment I should be keep sound from getting to the fuel tank compartment so what's the purpose of insulating that as well? Maybe to keep the hatch from vibrating, not sure but at $17 per 1 ft x 4.5 ft piece this is looking like a $68 to $85 Experiment (including the bulkheads in the fuel tank compartment). Given the costs and without baseline readings I will probably just convince myself that it helped. At least the install in this area is easy.

The product I used is designed to decrease vibration more than to reduce sound. It was $ 100 for 36 square feet. The fuel hatch is just under 12 sq/ft. Which works out to $33. I'm doing the engine compartment as well just haven't got around to it. Im also purchasing some 2" sound absorbing foam which I'm going to line the engine compartment with. I'm hoping lining the engine compartment with the foam will reduce some of the engine noise.

Back to to fuel hatch. Before I did it, when you knocked on it, the sound was ting,ting, ting. Now when you knock on it the sound is more of a thud thud thud. I'm not expecting miracles, but hoping the combination of these two products will help a little.

 

[Chillypilot]

You have to be careful with stuff from hardware stores. A lot of those products are tar based and give off fumes. Make sure it's butyl rubber.

 

[waterboy]

Last year, I just did the fuel hatch only and it was a pretty easy job. It made a big difference. Yes it is still loud, but I can hear conversation in the cockpit easier at speed. I can hear the stereo easier without cranking it up all the way. Oh, and no I didn;t get before and after data... sorry

Sure I could use it quieter, and probably will work on the engine hatch later. It is a much lower priority though after removing some of the noise.

 

[motorboater]

depending on the thickness of the material you are using on the fuel tank cover it may cause the forward part to be too thick to close correctly. If you notice, on the 240s, the cover sits over an area that is not very deep. I had to trim my insulation back or I couldnt close it. Personally i thought it was a waste of time but this is all subjective anyway so some others might disagree.

 

[steined]

depending on the thickness of the material you are using on the fuel tank cover it may cause the forward part to be too thick to close correctly. If you notice, on the 240s, the cover sits over an area that is not very deep. I had to trim my insulation back or I couldnt close it. Personally i thought it was a waste of time but this is all subjective anyway so some others might disagree.

What material did you use to attempt sound reduction? Just curious.

The Acoustiblok raised the floor very slightly. You can adjust the height of the "catches" on the cam locks but you really don't want much of a height difference as you stated!

 

[motorboater]

It'll be uneven with the floor. I used Second Skin Spectrum and Overkill Pro which is 3/8" thick.

 

[Ronnie]

I am only planning on covering the part of the floor hatch that has lots of space under it as well as the sides of the fuel tank compartment so I shouldn't have to deal with the issue of having an uneven floor. I agree with Steined on putting a little extra in the engine compartment where Yamaha did so I may double up there instead of doing the fuel tank compartment hatch or walls at all. It depends on how much material I have left when I get to the fuel tank.

Overall I think anything is better than nothing which is almost what yamaha "included". For instance, no seal on the engine hatch, mine had a thin strip if rubber about 8" long near the bottom but I think that was to keep the hatch from rubbing against the boat in that location not as sound deadening.

 

[steined]

OK I got out on the water and have some first impressions. When we initially started the boat, it seemed much quieter, the initial rattle of the impellers was more subdued, and it just seemed quieter. Got up to cruising speed and my wife said, "wow that really helped". My impression was more like, yeah it is better, but maybe not worth all the work. Basically the resonances were very nicely controlled and the edge was taken off the noises.

Then as it heated up we put up the Bimini. Wow. That made things much louder. Very noticeably louder.

I think someone else mentioned this too, but if you boat with the Bimini up the noise from the water increases a lot, and I think the exhaust noise does as well.

So I'm pleased with the reduction without the Bimini up, but not so happy when the Bimini is up.

All I've done is the fuel hatch and engine hatch at this point. I was hoping, and initially thought after riding with Bimini down, it was good enough, however I think I'm going to work on it a little more after riding with the Bimini up.

I still plan on that curtain idea and am also considering the clean out hatch lid. Maybe the top rear of the engine compartment as well. I'm just trying to block sound that is directed towards the cockpit at this point.

So while it was a noticeable improvement, it wasn't a miracle and with the Bimini up, it was still louder than I'd like.

Fell free to say I told you so

 

[Julian]

The fact that you think there is a noticable reduction (and your wife agrees) sounds like it was worth it to me! When I do something to the boat and the wife likes it I know it was worth it. So by that measure...

 

[Addicted]

I have installed 2-3 layers of foil faced butyl material on the engine hatch and fuel hatch, as well as foil faced acoustical foam on the engine hatch. I also added rubber weather stripping to the entire hatch perimeter. My opinion is it is a slight improvement, but not worth the money/effort. Once the first impression wears off, it seems just as loud as always. I would not do it again.

 

[Ronnie]

I am still working on mine but did use the original foam as a template and plan to install 1" foam throughout the engine compartment as well as on the fuel tank hatch. I've done this before and had the same impression (i.e., noticed the difference as did my wife and crew but was unsure if it was worth the effort and expense). I didn't realize that Bimini up or down would matter but if I have to choose I can live with the sound more than I can the best so the Bimini is not going anywhere.

In the short term it may not seem like its worth the effort or expense but if you are avoiding damage to your hearing and that of the crew in the long run i think it is worth every penny, second, drop of sweat and aching muscle.

 

[woodard1983]

Ronnie, here is a inexpensive alternative,

http://www.frostking.com/foil-and-fiberglass-duct-wrap/

be careful using this one...I haven't used that exact brand/model, but a lot of the duct/roofing barriers use a tar type substance...aka will start to smell like asphalt in a heated boat, especially if the cover is on....found this out in high school w/car audio installs, it is not fun taking this stuff off :/

 

[Evil Sports]

I used it in this and have not had any issues so far

 

[Ronnie]

I took some baseline decibel readings this past weekend after I removed all of the stock sound deadening foam and the hatch seal I installed last year. I may just reseal the hatch and put new material where the original material was before I take another set of readings than install sound deadening foam in the rest of the engine compartment before taking a final set of readings. I may make take readings after I install the material in the fuel tank compartment as well.