Engine noise reduction blanket

Your link doesn't seem to work properly, but I'm assuming you mean the Engine Box Blanket sold by NK Group. This is intended to go on the outside of the sort of engine cover often found in fishing boats, and would be totally unsuitable for a boat like yours.
 
Vertor said:
I am in the process of replacing my engine noise reduction and came across a marine engine blanket. I like the idea but am worried about heat retention issues.

I would incorporate ventilation and a good extraction fan. Does anyone have any experience of using an engine blanket such as this one?

https://www.nkgroup.co.uk/product/ma...ngine-blanket/

Thank you in advance for your advice.
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I had them on my old boat. They go directly on the engine and make quite a difference. Heat is taken from the engine via the water cooling so it causes no heat issues.
They can do Velcro together ones that do back and sides too.
They are heavy to take on and off for servicing but they do access flaps for dipsticks etc.
 
I researched them a few years ago and was assured that they would work well. The people I spoke to made more-or-less custom versions and could incorporate flaps anywhere they were needed for alternator, dipstick etc. I cannot see heat retention being a problem as air cooling of the block has an almost negligible effect, it's the coolant that does all the work.

In the end I improved the engine box instead so did not go ahead.
 
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Last time I read a similar thread there were concerns that bits like the alternator could get over hot if enclosed.
My engine bay would be cow to lnsulate (I have done the engine cover and this made a good difference) but the sides would be much more difficult.
Depending on further responses I will !measure up and get a price.
 
pcatterall said:
Last time I read a similar thread there were concerns that bits like the alternator could get over hot if enclosed.
My engine bay would be cow to lnsulate (I have done the engine cover and this made a good difference) but the sides would be much more difficult.
Depending on further responses I will !measure up and get a price.
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You are right I should have said that. The alternator is air cooled and you need to keep it out in the open. You have to keep the blanket from the belts anyway. The rest of the engine is fine.
 
pcatterall said:
Last time I read a similar thread there were concerns that bits like the alternator could get over hot if enclosed.
My engine bay would be cow to lnsulate (I have done the engine cover and this made a good difference) but the sides would be much more difficult.
Depending on further responses I will !measure up and get a price.
Click to expand...

You are right I should have said that. The alternator is air cooled and you need to keep it out in the open. You have to keep the blanket from the belts anyway. The rest of the engine is fine.
 
Not on a bet.

They can become soaked with oil, and then if in contact with exhaust ports, begin to smolder. Ive seen these catch fire with my own eyes. We caught it before it spread far, but there was smoke.

Not a small, perhaps tiny risk, but far greater than the benefit. Fire on a boat is terrible, and that is an understatement.

Also, not in the above image that there were hoses and wires under the blanket. No thanks. Just not seeing it. The ONLY reason I would do this is for winter opperability in below freezing temperatures, but I doubt may of you do that.
 
Did a measure up possibly in order to get a quote. To keep it simple and easy to remove there would still be some areas not blanketed especially over the alternator and around the back of the gear box.
I had understood that good sound proofing requires no 'holes' ? Is this really critical or is 75% cover going to achieve decent noise loss?
Covering the hatches did make a significant reduction (say 25%)
 
thinwater said:
Not on a bet.

They can become soaked with oil, and then if in contact with exhaust ports, begin to smolder. Ive seen these catch fire with my own eyes. We caught it before it spread far, but there was smoke.

Not a small, perhaps tiny risk, but far greater than the benefit. Fire on a boat is terrible, and that is an understatement.

Also, not in the above image that there were hoses and wires under the blanket. No thanks. Just not seeing it. The ONLY reason I would do this is for winter opperability in below freezing temperatures, but I doubt may of you do that.
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They are in an oil proof jacket. Splashed oil won’t get into the foam. If you soak it in a puddle of oil you’re right. But why would you do that?
 
Elessar said:
They are in an oil proof jacket. Splashed oil won’t get into the foam. If you soak it in a puddle of oil you’re right. But why would you do that?
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I reported what I saw. Obviously there was a leak. Your mileage may vary, but I'm not interested in anything that restricts access or increases fire risk, at all. Just not interested.

And just how much of that are you going to jacket without covering something you need access to or which must get air? On a sailboat engine, probably 30% on a good day.

engine-600x762.jpg
 
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thinwater said:
And just how much of that are you going to jacket without covering something you need access to or which must get air? On a sailboat engine, probably 30% on a good day.
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Alternators are air-cooled and obviously air needs to get to the intake. Otherwise, what on an engine needs air?

Given the choice I’d insulate the engine compartment rather than use this (and that’s exactly what I did) but it doesn’t seem like a terrible idea to me if the compartment can’t be insulated for some reason. Doing something to replace the few scraps of basic lightweight foam I inherited made a big difference to the habitability of the boat under power - previously you couldn’t even speak to someone in the cabin.

Pete
 
If you wanted to try a DIY cheap job then buy some 25 Th rockwool sound deadening quilt 11 M2 for about 20-00.Then tack glue to the wood/GRP compartment panels.

Cover the exposed surface with aluminium foil (you could treat the surface with emulsion paint to keep the fibres in place & reduce oil absorption) & then chicken wire. Then hold that in place with narrow strips of thin ply screwed through the lot to the wood/GRP at the back. That will cover the sharp edges of the chicken wire at panel edges & any middle bits to reduce bulging
 
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Sandy said:
A duvet for a heat producing engine, what could possibly go wrong?
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My launch has it & there is no problem. Very effective, as when the lid over the engine is opened one can notice a significant difference . One does not have to sound proof the entire areas. For instance the area that divides the cabin & the engine or, say, berth & engine.
In my yacht there is a large open area under the cockpit past the sail drive etc where heat can be dissipated
 
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Daydream believer said:
If you wanted to try a DIY cheap job then buy some 25 Th rockwool sound deadening quilt 11 M2 for about 20-00.Then tack glue to the wood/GRP compartment panels.

Cover the exposed surface with aluminium foil (you could treat the surface with emulsion paint to keep the fibres in place & reduce oil absorption) & then chicken wire. Then hold that in place with narrow strips of thin ply screwed through the lot to the wood/GRP at the back. That will cover the sharp edges of the chicken wire at panel edges & any middle bits to reduce bulging
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Would only reduce the high frequency noise. Diesel engines have a lot of low frequency noise.
The blankets have 5kg per sq m of lead in them sandwiched between the foam. It’s mass that reduces low frequencies.
 
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thinwater said:
I reported what I saw. Obviously there was a leak. Your mileage may vary, but I'm not interested in anything that restricts access or increases fire risk, at all. Just not interested.

And just how much of that are you going to jacket without covering something you need access to or which must get air? On a sailboat engine, probably 30% on a good day.

View attachment 81197
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It’s fine that you’re not interested but don’t dismiss it for others with erroneous assumptions.
It Velcros off in senconds. You can cover almost the whole engine. I agree that doing the engine bay properly is preferred but for many boats where the engine compartment goes to an open void under the cockpit or transom this is impractical. This is another solution that can work well for some.
 
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