Diesel engine noise insulation

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adamstjohn

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Hello all, advise needed re title. Small 14 hp Nanni diesel , anybody used any very cost effective noise insulation panels/materials ? Heat proof? fire resistant? its a noisy little devil.............Ta adam
 
There are all sorts of noise insulation materials materials available, the thicker the better and the more expensive.

But more important is to maintain a good a good air flow and this can mean holes in the insulation rendering it all but useless.

We have cat with twin VP sail drives and wanted them to super quiet. Not a major problem when each engine was fitted with a solid bulkhead for and aft.

The major contributor to lack of noise was fitting dorade vents on deck and running an 8 inch hose to the bottom of each hull and making the only entry / exit point a large hatch on deck.

Result, no trace of any fumes or fuel smell in any of the cabins and the stereo is not drowned out to the point it has be turned up.

Good luck and fair winds. :)
 
Best place to buy soundproofing panels at low cost is probably boat jumbles.
There's always a stand at the ones I've been to with a stack of soundproofing - I think they were about £18 each at the Newark one a couple of weeks ago. Panels were about 4ft x 2ft ish, maybe slightly bigger or metric (1200x1000?)

Have a search for the next / nearest boat jumble to where you are. 'Tis the season at the moment, there are a few on.

Edit: was going to add, you need soft compliant foam either side of a good dense layer (usually bitumen or similar, altho lead is best you prob won't see it available). Usually coated with a silver / heat resistant finish. Best if this is also tear resistant.

Eliminate as many gaps as you can for best effect when fitting. It's the gaps where the noise escapes!
 
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I'd suggest a composite material with more layers of different density, one stiffer/heavier.

By far better than plain foam - the one I got last had a 40 db dampening and were compliant to '94/25 EG. ISO 3795' for use in boats.

vb-tsm-lg.jpg


Try Google or eBay for 'Sound Proofing Deadening'
 
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Chatting on the Beta stand at the London Boat Show, they will supply soundproofing cut to size for small engines as they get a lot of wastage from some large instaliations. Worth a phone call.
 
I've used Vetus white foam and 1.5mm pure lead sheet on my boat.The result is very good indeed if a little heavy but since I upgraded to a Beta 20 from a Bukh that weighed 100kgs more, I've still saved on weight.
 
Champagne Murphy said:
I bought mine from this guy, http://www.bridgerubber.co.uk/index.php?route=product/category&path=62_77
Found him at a jumble and used him a couple of times, much cheaper than chandleries, I found
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I'd found the same supplier via eBay, though I was planning to deal with him direct since he's just down the river from the boat :). Soundproofing the engine bay is on my list for this winter, though I haven't really done much about it yet.

Is this guy's stuff good? I guess it must be ok if you've used it twice.

Do his panels have finished edges, or do I need to allow enough silver tape to apply around the bottom for a neat ending?

General questions for you or anyone else -

- What's best for mounting this sort of foam?
- I have a number of access panels, flaps, and doors; is there a good way of sealing the joints?
- I have a lot of pipes and hoses to secure along one side of the engine bay. Thoughts on mounting these - just screw straight through the foam and squash it under the fitting? Install stand-offs through it? Something else?

Cheers,

Pete
 
Have you thought about an acoustic blanket?
They sit on top of the engine itself wrapping down over the head which is where most of the tappet rattle comes from.
No problems with engine aspiration.
 
Lots of interesting food for thought there, thanks people.
Think I may go to the Ipswich boat jumble and see what I can get, we have spent all of our boat maintenance money so have to do this on the very cheap, sure I will find something, its a tiny area after all. Cheers
 
prv said:
I'd found the same supplier via eBay, though I was planning to deal with him direct since he's just down the river from the boat :). Soundproofing the engine bay is on my list for this winter, though I haven't really done much about it yet.

Is this guy's stuff good? I guess it must be ok if you've used it twice.

Do his panels have finished edges, or do I need to allow enough silver tape to apply around the bottom for a neat ending?

General questions for you or anyone else -

- What's best for mounting this sort of foam?
- I have a number of access panels, flaps, and doors; is there a good way of sealing the joints?
- I have a lot of pipes and hoses to secure along one side of the engine bay. Thoughts on mounting these - just screw straight through the foam and squash it under the fitting? Install stand-offs through it? Something else?

Cheers,

Pete
Click to expand...
I used large plastic washers supplied by ASAP Supplies, who also supplied the insulation material. Cut to size and then just screwed to
the sides and top of the engine compartment. Much better than the stick-on stuff, which in my experience falls off eventually.
 
prv said:
I'd found the same supplier via eBay, though I was planning to deal with him direct since he's just down the river from the boat :). Soundproofing the engine bay is on my list for this winter, though I haven't really done much about it yet.

Is this guy's stuff good? I guess it must be ok if you've used it twice.

Do his panels have finished edges, or do I need to allow enough silver tape to apply around the bottom for a neat ending?

General questions for you or anyone else -

- What's best for mounting this sort of foam?
- I have a number of access panels, flaps, and doors; is there a good way of sealing the joints?
- I have a lot of pipes and hoses to secure along one side of the engine bay. Thoughts on mounting these - just screw straight through the foam and squash it under the fitting? Install stand-offs through it? Something else?

Cheers,

Pete
Click to expand...

PM sent
Karl
 
I've used this with excellent results. I've fixed it to the underside of the cockpit floor, lining the engine box and also used an offcut as a noise barrier blanket which lies on top of the engine to cut down on the din from the valve gear and injectors. The adhesive is very strong but I also used screws and stainless mudguard washers as well.

http://www.nkgroup.co.uk/product/noisekiller-lead-sandwich-material/

Its not cheap and is heavy but you'd be unlikely to find anything better.
 
ianj99 said:
you'd be unlikely to find anything better.
Click to expand...

I did actually find a rogue PDF of the YM article mentioned above. The Noisekiller sandwich is one of the less effective products in their test - though it's not a fair test as most of the other products are twice as thick or more. So if you have limited space for thick foam then the Noisekiller sandwich is a good choice, and I'm going with it for exactly that reason. But if you have room for 30, 40, 50mm of foam and polymer instead of 15mm of foam and lead, you can (according to the unscientific YM test) halve the noise level again.

Noisekiller are sending me some small offcuts as samples while I measure up for the main order. I'm going to mount it with penny washers the same as you. Interesting idea with the blanket directly on the engine, I'll see if I have a suitable bit left over. I'm actually thinking of using up the extra by doubling up the thickness in places where there's room, I assume that'll make it even more effective.

Pete
 
prv said:
I did actually find a rogue PDF of the YM article mentioned above. The Noisekiller sandwich is one of the less effective products in their test - though it's not a fair test as most of the other products are twice as thick or more. So if you have limited space for thick foam then the Noisekiller sandwich is a good choice, and I'm going with it for exactly that reason. But if you have room for 30, 40, 50mm of foam and polymer instead of 15mm of foam and lead, you can (according to the unscientific YM test) halve the noise level again.

Noisekiller are sending me some small offcuts as samples while I measure up for the main order. I'm going to mount it with penny washers the same as you. Interesting idea with the blanket directly on the engine, I'll see if I have a suitable bit left over. I'm actually thinking of using up the extra by doubling up the thickness in places where there's room, I assume that'll make it even more effective.

Pete
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The engine blanket does make a difference so the main soundproofing has a bit less to block and absorb.
RSWWW used to stock a polymeric barrier and polyester fibre sheet which also works well - that + the lead sandwich would be excellent.
 
adamstjohn said:
Lots of interesting food for thought there, thanks people.
Think I may go to the Ipswich boat jumble and see what I can get, we have spent all of our boat maintenance money so have to do this on the very cheap, sure I will find something, its a tiny area after all. Cheers
Click to expand...

Don't waste your money or effort doing it on the cheap. Save up to buy the best material you can from Halyard or Vetus. Most of the work is stripping the engine bay to fit it properly. Like arrived you will get the pleasure long after you have forgotten the cost, which in the scheme of things is not that much more than using cheap stuff.
 
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