Soundshield Rehab

[Capt Chad]

The Onan 15kw on the boat only has about 1700hrs on it and runs great. BUT, it's loud as hell in the salon.

Definitely gonna keep it for a while so... Probably time to do some work on the factory soundshield.

The front 1/2 cover over the filters and oil fill doesn't even have insulation attached. it just lays in there against it. My thought is to pull one panel off at a time and attach 1" Sounddown panels or something similar.

Has anyone done this? How heavy is the product? Is it pliable or stiff? Adhere it to the soundshield or use fasteners?

Has anyone used a similar product they liked better?

Thanks

 

[bobk]

Many eons ago I had a one lung Volvo diesel powered generator. I built a hush box from fire retardant acoustic ceiling and it made a huge difference. Just be sure you do not interfere with the air flow.

Bobk

 

[Colwyn D]

I'd also be interested in this. My NL enclosure is forever dumping it's insulation on the engine, especially the overhead panel. What adhesive to use, I've been considering 5200 or similar.

 

[rwappleton]

I will be watching.....our 9MDKAL is shedding the foam on the inside of the box. Seems to be both foam deterioration and adhesive release.

 

[seasalt]

I just replaced the insulation on my NL. I got the material from West. The hardest part was getting all the old stuff's adhesive off. Quite as a mouse now.

 

[dsharp]

Sound down makes a pin that is attached to a square perforated tab. They then have a cap that presses over the pin to hold the sound deadening material on . If you clean your panels well I would think 5200 or thickened epoxy would hold the tabs on. Donovan's marine in New Orleans had a good selection of sound deadening material.

 

[Capt Chad]

I just ordered 1 panel of 1" Sound Down material and the pin kit that was mentioned to see if it's how I want to go.

I will keep you guys updated on how it works.

 

[gbharrington]

I replaced the useless fiberglass insulation on my OEM Onan sound shield with 1" Soundown last year and it made a big difference, although there is NO doubt that the gen is running, regardless of where you are in the boat. I plan to install vibration dampeners this winter to reduce the low frequency noise.

 

[sandspur1966]

You can have a sound shiel blanket sewn to the exact dimension of the box for very little money and zero effort.

Any time you need to access you just lift off the blanket... easy peasey and double the attenuation.

 

[jim rosenthal]

Any suggestions on a supplier for one of those? The generator in Blue Note is LOUD. Most of it is low-frequency sound, but perhaps a sound enclosure might help.

 

[johnjen50]

Agreed. I would like to know as well. I assume the blanket allows for adequate ventilation for the electric side too?

 

[Capt Chad]

I never considered a blanket either. Maybe even Velcro in a door in the front for the access panel to check the oil.

 

[sandspur1966]

There tend to be shops that make them up in any area and shipping adds some cost so you may wish to look in your own backyard first.

The costs vary greatly depending on many parameters including the type of material and whether seams are sewn or stapled and how complex the job is. etc etc. they can meet any vent requirements you need.

The last time i had it done was for the exhaust blankets and i used a shop out of biloxi who used a nice black product that hides dirt etc and i went the cheaper route and hat the seams stapled. Both mains cost me less than 1k if i remember correctly i will find the receipt on the boat tonight and post them.

Hope that helps.

 

[gbharrington]

I would suggest to anyone considering a blanket over a Soundown type product that they do their homework. Blankets typically do not have a mass loaded vinyl (MLV)barrier or any other high density material that is the core of any sound attenuation. Soundown with the commonly used 1/8" MLV weighs 1 lb/sq.ft., while the 2"blanket is about half of that. Additionally, based on what I've seen online, the blanket material is around 50% more expensive.
Now back when I was active in the business, they used lead filled blankets on the walls in commercial aircraft cabins. That is probably the most effective approach, but I can promise you they are not cheap.

So from my perspective, if you don't already have an enclosure, a blanket may be the way to go. One of the blanket manufacturers suggested combining the blanket with an MLV barrier. Don't know how that works, but it's probably doable, although the price will go up accordingly. But if you do have an enclosure, than replacing the fiberglass batting material with a MLV based product (such as Soundown) is the way to go.

It's all about density!

 

[Capt Chad]

I am using the Sounddown supplied install pins that you adhere to the shield. Has anyone used these pins? What did you use to stick them to the shield? West Systems, flexible adhesive like 5200?

 

[Capt Chad]

I've got 2 panels ready to go. Can't get the back panel off without cutting carpet in the salon. The old fiberglass insulation looks to be in pretty good shape though. Gonna attach the top and the side panels tonight.

The 1" Soundown material is pretty impressive. Heavy stuff. I may have to hire a small person to help me get the top panel back to the genny. Can't wait to hear the difference.

Thickened West Systems worked well for the pins. I might actually use stainless hardware and thru bolt the stuff to the top of the shield though.

 

[johnjen50]

Any Pics Capt Chad?

 

[Geoff58yf]

We pulled out all the old foam material and lined the inside with Dynamat
http://www.dynamat.com/automotive-and-transportation/automotive-restoration/dynamat-xtreme/
Dynamat has some terrific sound deadening products (and some with amazing self adhesive). We evne made sound shields for the head pumps. All sizes are easy to use and didnt break the bank.

 

[Capt Chad]

 

[Capt Chad]

Got all the panels finished up and ready to go back in. I probably have $250 in materials. 2 rolls of 1" Soundown, got the job done ( minus the back panel which I can't get out without removing the salon floor). I feel pretty confident that this will greatly reduce the noise in the cabin. I will let you guys know how it works out this weekend.