Engine Soundproofing

[boatone]

I know about the lead barrier soundproofing materials one can line the engine compartment with, but has anyone tried the various thoinner soundproofing mat /underlay materials that can be laid on the cockpit floor. They are actually made for floor soundproofing in flats etc and are about 12mm thick.
I tried a little experiment the other day and laid the foam cushions from the dinette over the engine hatch on my P32 - sound reduction was quite remarkable even tho I already have underhatch soundproofing of the barrier type.
I think some sort of underlay and a cockpit carpet might actually prove very effective.

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[BarryH]

What do you mean, the knocks bangs and clangs are music to my ears!, I need em'. That way I know the red dread is running!!

OK, to hell with it. Unbolt it and we'll use it as an anchor!

 

[Andrew_Fanner]

Could be interesting.

I note that MBM are doijng an article on soundproofing in the next mag. I emailed with a "pretty please" for a sneak preview as I've got to fit the stuff this w/e, but no response or joy (yet?)

What's the trade name for the stuff in case I run out of lead/foam?

Two beers please, my friend is paying.

 

[ultrarep]

Just did my noisy engine bay last weekend with self adhesive backed 38mm thick foil faced sheets. 4 sheets 4x2 £75 all in and has to be the best wad I have ever spent! The idle noise is down by about 20% but cruising noise is down by at least 60%. All i can here at 3000 rpm is the exhaust and the watery swish from the out drive. Fabulous. And only took 30 mins to fit. Engine is an aq145 petrol in a Fairline Holiday.
I wonder if it will work on the whining noise I get from the car when taking the wife shopping?!!**??

 

[boatone]

Well, has to be worth a try and not too expensive.
I've just ordered three sheets of a sound barrier mat 1800mm x 1200mm at £14.20 a sheet plus carriage and vat.
You can read about the stuff at their website<A target="_blank" HREF=http://www.customaudiodesigns.co.uk/soundproofing/barriermat.htm> here </A>
The guy tells me that one or two layers under a carpet should be very effective against airborne noise - its 2-3 mm thick but quite heavy at 5Kg per sq. metre

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[boatone]

Re: Knocks, bangs and clanks.......

...........are not the sort of noise I'm worried about (tho if I had them I guess I'd be rather concerned). I'm simply trying to dampen down the steady drone of my two 106HP diesels coming from the hatch in the rear of the cockpit. Not so bad when the canopy is down cos it can escape but its amazing how much noisier it is at the helm when the canopy is up.

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[boatone]

Single petrol........

.........and you reckon it was noisy? Wow, these Holidays cant be built as well as Sandra keeps telling me they are !!!
And now you're trying to get a load of you together all in one place .......let us know where and when so's we can be someplace else !


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[BarryH]

Re: Knocks, bangs and clanks.......

On a more serious note, I've just been going through my insurance doc's as its coming up for renewal. There's a clause in them that mentions alterations to the "Vessel" and materials used in said alterations. In short any "lagging" or "Sound deadening" materials should be "Type approved" and fit for service.

Thats the insurance companies words not mine. So the million dollar question is, If you use said felt/foam panels designed for the floors in domestic dwellings, are you covered by your insurance. Why can't things be black and white!!

OK, to hell with it. Unbolt it and we'll use it as an anchor!

 

[boatone]

Re: Knocks, bangs and clanks.......

Given that fire risk must key issue this stuff certainly looks good for purpose:

Flammability Zero burn rate (FMVSS 302)
Service Temp. <90°C for extended periods <120°C for short periods






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[BarryH]

Re: Knocks, bangs and clanks.......

Sounds good, I'm looking for something for the engine space in the Tremlett. It has no proofing at the moment so anything over 3000 revs and its no speaking or hearing (could be a good thing). I contacted my insurance co regarding "type approved" materials but as yet no reply. Flamability has got to be high on the agenda as its a petrol boat.

OK, to hell with it. Unbolt it and we'll use it as an anchor!

 

[Pendana]

Re: Sandra ...?

Phew ... stepping close to the edge aren't ye ! Hell hath no fury like a Sandra's wrath

Anyway, keep us posted with the sound proofing scheme it might be just the stuff I could use deaden the noise from a pair of AD31's

Eddie S

 

[boatone]

Naaaah.....

....Sandra's a pussy cat really. He and I understand each other y'see !

Should have the stuff here by the weekend so will report back soonest. Also got to find a nice dark grey hardwearing waterproof carpet to finish the job off.


<A target="_blank" HREF=http://www.arweb.co.uk/argallery/mobochat> My P32 and Boaters Picture Gallery</A>

 

[muchy_]

Also did my engine bay with the 38mm sticky back foil fronted stuff. Best 135 quid I ever spent (almost). What did sound like an old diesel truck now sounds like a little diesel escort. Massive difference. I'm also going to lay carpet and underlay so with a bit of luck this should make it even quieter.

 

[boatone]

Well, the stuff duly arrived and I fitted it this weekend. Apart from the fact that its quite heavy and makes it more difficult to lift the engine hatch (which on the Princess 32 is already heavy!) it's very unobtrusive being only around 2-3 mm thick. I also got some nice new carpet at the same time - struck lucky at the local carpet shop and completely recarpetted the cockpit for £25.
Anyway, I have to say the improvement in noise reduction is remarkable. The engines positively purr now and when ticking over they're quite difficult to hear at all inside the cockpit. A visitor (another boat owner) said if he hadnt known they were diesels he'd have thought they were petrol and promptly said he'd buy a left over roll from me!
For those interested in refurbishment projects I've put before and after pics of my helm area on the website - see below.


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[lanason]

Re: Single petrol........

Jealousy will get you everywhere )

Actually I think I will put some in my Engine bay - its massive I can easily get inside on BOTH sides. Very useful with a Volvo !!!!! But acts like a bass speaker .........

Ultrarep - where did you gets your stuff from ????

Adrian

......the answer is not 42 - so what is it ?? ........

 

[Andrew_Fanner]

Fitted my stuff this w/e too, well apart from one panel where I can't tell how much of a cutout is needed for a bit of framing, until the frame is back in, over the engine. Looks promising but makes the panels pretty heavy.

Now lets see when the engine actually goes back in.

Two beers please, my friend is paying.

 

[tcm]

Not tried the specific products you mention, but extra soundproofing continues to have an effect for thicknesses up to at least 6 inches thick, I'm told. So, borrow the cockpit cushions off the guy next door and have a nice splooshy comfy cockpit comprising nice deep foam and everyone lolls about, rather than all this sitting upright. Wearing togas might be appropriate.