stretch33
New member
Anyone got any opinions on the self adhesive stuff that Halyard do, or better still recommendations of the best stuff to use for engine comp. Cheers
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Sound insulation
- Thread starter stretch33
- Start date
dignity
New member
I used a lead barrier proofing to sound-proof my engine room on my steel motor barge with great success, it's called quiet-life from asap-supplies, the only trouble is it's very heavy so it has to be fastened rather than stuck.
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NigeCh
New member
More info rqd.
What's the problem? and what do you wish to achieve?
Sound insulation is a complex subject that is unfathomable by the layperson. It's a subject that has been ignored by PBO and her sister magazines. It would take at least 3 issues of PBO to give a meaningful and practical set of articles that would show you how to soundproof your engine compartment properly.
And the articles would also show how and why self adhesive glues fail.
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What's the problem? and what do you wish to achieve?
Sound insulation is a complex subject that is unfathomable by the layperson. It's a subject that has been ignored by PBO and her sister magazines. It would take at least 3 issues of PBO to give a meaningful and practical set of articles that would show you how to soundproof your engine compartment properly.
And the articles would also show how and why self adhesive glues fail.
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vyv_cox
Well-known member
I applied the Halyard product about 4-5 years ago with great success. Sound level reduced considerably and none of it has fallen off. The appearance is good too, the white glass finish giving better light levels. I used the type with internal lead sheet. All internal corners filled with silicone sealant, more for appearance than sound deadening, although it may help. It seems to be important to completely enclose the engine space for best effect. I confess that I did not but still pleased with the results.
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NigeCh
New member
Enclosure
For enclosure read total enclosure ... and then there are engine mounts. limbers, flanking transmissions and air intake to the engine to consider too. (Exhaust noise becomes trivial relative to the above)
Just for fun, a Yanmar 1GM10 produces 93 dB at I metre .... So how are you going to silence that ???
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For enclosure read total enclosure ... and then there are engine mounts. limbers, flanking transmissions and air intake to the engine to consider too. (Exhaust noise becomes trivial relative to the above)
Just for fun, a Yanmar 1GM10 produces 93 dB at I metre .... So how are you going to silence that ???
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Paul_H
New member
Ive got the Halyard stick on insulation and it works fine. It was already fitted so dont know what its like to diy. Vyv's got it right. Fully encasing the engine is essential and dont leave any gaps eg round plumbing and hatch edges. I had some relatively small gaps around a hatch cover and once sealed made a big difference to the noise in the cockpit. The insulation should be secondary helping to deaden the vibration of panels around the engine. Dont forget to provide an air feed to the engine when you box it in.
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tcm
...
Hi. As some of the posts suggest, sound PROOFing is a masive subject.
But using the Halyardstuff I had good results. To the side of the engine, adhesive is fine, but clean it as the adhesive is very strong. Above, i reinforced with wooden battens to make surte the stuiff wouldn't fall down. A good seal around the engine access is important.
There are several types, all fairly expensive - with a white glas cover it is brighter, but with that or the silver glass matt finish (is is foam with a plastic layer) be careful of the fibres whic hare an irritant and dangerous - using protective clothing and or barrier cream is good. But even with cheaper foild backing, it is still pretyy good stuff, all flame proof and so on.
the non-adhesive (which i tried on another boat ) is much harder to use, not rec'd. Also, the effect of soundproofing barrier improves and improves to at least 6 inches thick (!) so you can double up - but single thickness is fine. They do a nice tape (grey material) which is heat resistant, and finishes edges nicely.
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But using the Halyardstuff I had good results. To the side of the engine, adhesive is fine, but clean it as the adhesive is very strong. Above, i reinforced with wooden battens to make surte the stuiff wouldn't fall down. A good seal around the engine access is important.
There are several types, all fairly expensive - with a white glas cover it is brighter, but with that or the silver glass matt finish (is is foam with a plastic layer) be careful of the fibres whic hare an irritant and dangerous - using protective clothing and or barrier cream is good. But even with cheaper foild backing, it is still pretyy good stuff, all flame proof and so on.
the non-adhesive (which i tried on another boat ) is much harder to use, not rec'd. Also, the effect of soundproofing barrier improves and improves to at least 6 inches thick (!) so you can double up - but single thickness is fine. They do a nice tape (grey material) which is heat resistant, and finishes edges nicely.
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Paulka
New member
I insulated my engine compartment with Halyard materials nearly 4 years ago, and am fully satisfied.
On suggestion of Halyard I choosed the self adhesive sort, and I am surprised how well it does. Maybe it's a result of the great care I took to sand the old glue away, right down to the timber, and to apply a primer on all surfaces prior to install the isolating material.
None went loose up to now despite the very high temperature reigning in the engine room after several hours motoring under the mediterranean sun.
Good luck.
Paul
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On suggestion of Halyard I choosed the self adhesive sort, and I am surprised how well it does. Maybe it's a result of the great care I took to sand the old glue away, right down to the timber, and to apply a primer on all surfaces prior to install the isolating material.
None went loose up to now despite the very high temperature reigning in the engine room after several hours motoring under the mediterranean sun.
Good luck.
Paul
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gtmoore
New member
I used the Quiet Life product from ASAP too and have been very pleased with it. I went for the slightly cheaper polymetric barrier which is supposed to be nearly as good as the lead version. This was also very heavy. It was the non-adhesive version and I used a contact adhesive together with large plastic saucer washers also from ASAP.
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stretch33
New member
Thank you all for your replies, in response to Nigech l don't expect to have a totally silent engine but some reduction in noise has got to be beneficial. The old BMC shakes and rattles like mad. Currently the engine box has just a thin sheet of egg box type foam on the front and lid. This l have to say is as much use as a concrete parachute. Like Vyv it won't be completely sealed in as need access to back of engine from cockpit locker.
Thx all Phil
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Thx all Phil
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vyv_cox
Well-known member
Re: Enclosure
I agree that for the best possible results the engine should be totally enclosed but this is impossible in most small boat engine compartments. I replaced the original 'egg-box' type foam with the Halyard stuff and a considerable improvement in sound levels was made.
Every year at the Amsterdam show there is a demonstration of sound deadening material. It's a compressor running inside a totally lined box. With the lid on it is not possible to hear any sound, despite pressing ears to the box. With the lid open it's virtually as noisy as a diesel engine.
Transmitted noise is something else, and most of my engine noise comes this way, despite fitting an Aquadrive which in my experience has been very disappointing.
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I agree that for the best possible results the engine should be totally enclosed but this is impossible in most small boat engine compartments. I replaced the original 'egg-box' type foam with the Halyard stuff and a considerable improvement in sound levels was made.
Every year at the Amsterdam show there is a demonstration of sound deadening material. It's a compressor running inside a totally lined box. With the lid on it is not possible to hear any sound, despite pressing ears to the box. With the lid open it's virtually as noisy as a diesel engine.
Transmitted noise is something else, and most of my engine noise comes this way, despite fitting an Aquadrive which in my experience has been very disappointing.
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NigeCh
New member
Some numbers
Let's assume that your BMC engine is 4 cylinders. Let's also assume that it produces 93 x 4 dB at 1m = ~100 dB. Assume that the engine compartment is surrounded by 1/2" plywood with holes for wires and fairly tight access covers. Now fill the holes that the wires go through with a none setting mastic and your immediate sound reduction is in the order of -20dB giving you a net of 80 dB percieved noise. If you leave the holes for the wires open you can add another 6 dB so that you will be hearing, say, about 86dB.
The eggbox type foam is an absorber on. It provides no sound insulation whatsoever. It's absortion is a max of -3bB .... So the noise level that you are probably getting is in the order of say 83dB.
What you are trying to achieve is a background noise level with the engine running so that you can converse normally anywhere within say 1m of the engine compartment. If you now have the space in the engine compartment to line all the surfaces between the engine compartment and the rest of the boat that are in a direct line between the engine and the ear then if you use Halyard 45mm you should be able to reduce the perceived noise level by at least -20 dB giving you a net level of about 63 dB. So what does 63dB mean in practice? It means that you should be able to listen to the VHF with full articulation with the volume control set just above the level that it would be set if the engine was not running, and that with the engine running you would be conversing at say 1.5m from the engine with a slightly raised voice.
The original question related to Halyard self adhesive sheets. The problem here is that the glue is often stronger than the background. If that's the case, it will fail over some period. What you have to do with the background is to prepare it to make it stronger than the glue. What you have to do is strip off all the egg crate foam and get back to the original surface. If it's GPR then that's OK because it's already stronger than the glue. If it's wood then you have to find some penetrating finish that will penetrate to at least 1.5mm and harden to a varnish like finish. (The reason is as follows: if the background is softer than the glue then the background will delaminate and the insulation sheets will fall off.)
The key to sound insulation is: a) seal all holes if possible, but still allow free air intake either directly or indirectly for the engine; b) prepare the background engine compartment material so that it becomes stronger than the glue; c) apply the maximum thickness of Halyard sound insulation sheets that you can fit; d) tape all butt joints; and e) ensure that all openings (ie hatches) to the engine compartment are sealed (ie draught strip or whatever)
There are other sources of noise: a) engine mount induced vibration; b) propshaft induced vibration; c) exhaust noise; and d) flanking transmissions ie (very simplisticly) where sound goes round corners and/or is transmitted to the boat structure.
If you reduce the engine noise you will probably find that the above 4 types of generated noise will start to annoy you as they will become dominant .... and then we are into another ball game.
Acoustics is a nightmare ... but it's all solvable on a step by step process.
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Let's assume that your BMC engine is 4 cylinders. Let's also assume that it produces 93 x 4 dB at 1m = ~100 dB. Assume that the engine compartment is surrounded by 1/2" plywood with holes for wires and fairly tight access covers. Now fill the holes that the wires go through with a none setting mastic and your immediate sound reduction is in the order of -20dB giving you a net of 80 dB percieved noise. If you leave the holes for the wires open you can add another 6 dB so that you will be hearing, say, about 86dB.
The eggbox type foam is an absorber on. It provides no sound insulation whatsoever. It's absortion is a max of -3bB .... So the noise level that you are probably getting is in the order of say 83dB.
What you are trying to achieve is a background noise level with the engine running so that you can converse normally anywhere within say 1m of the engine compartment. If you now have the space in the engine compartment to line all the surfaces between the engine compartment and the rest of the boat that are in a direct line between the engine and the ear then if you use Halyard 45mm you should be able to reduce the perceived noise level by at least -20 dB giving you a net level of about 63 dB. So what does 63dB mean in practice? It means that you should be able to listen to the VHF with full articulation with the volume control set just above the level that it would be set if the engine was not running, and that with the engine running you would be conversing at say 1.5m from the engine with a slightly raised voice.
The original question related to Halyard self adhesive sheets. The problem here is that the glue is often stronger than the background. If that's the case, it will fail over some period. What you have to do with the background is to prepare it to make it stronger than the glue. What you have to do is strip off all the egg crate foam and get back to the original surface. If it's GPR then that's OK because it's already stronger than the glue. If it's wood then you have to find some penetrating finish that will penetrate to at least 1.5mm and harden to a varnish like finish. (The reason is as follows: if the background is softer than the glue then the background will delaminate and the insulation sheets will fall off.)
The key to sound insulation is: a) seal all holes if possible, but still allow free air intake either directly or indirectly for the engine; b) prepare the background engine compartment material so that it becomes stronger than the glue; c) apply the maximum thickness of Halyard sound insulation sheets that you can fit; d) tape all butt joints; and e) ensure that all openings (ie hatches) to the engine compartment are sealed (ie draught strip or whatever)
There are other sources of noise: a) engine mount induced vibration; b) propshaft induced vibration; c) exhaust noise; and d) flanking transmissions ie (very simplisticly) where sound goes round corners and/or is transmitted to the boat structure.
If you reduce the engine noise you will probably find that the above 4 types of generated noise will start to annoy you as they will become dominant .... and then we are into another ball game.
Acoustics is a nightmare ... but it's all solvable on a step by step process.
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stretch33
New member
Re: Some numbers
Thx once again for your comments, l appreciate its a very complicated area and your right it would be great to hear the vhf set at normal volume. Cheers
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Thx once again for your comments, l appreciate its a very complicated area and your right it would be great to hear the vhf set at normal volume. Cheers
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Birdseye
Well-known member
Re: Some numbers
interesting comments. i have a prout cat (with a single central engine and a catamaran drive leg) and will be insulating the bay with foam over the winter. however, i already know that a significant amount of noise is structure born, most (i suspect) from the drive leg which is bolted to the transom (ie the prop beat).
anybody know of an insulating material which i can sandwich between the aluminium mounting plate of the drive leg and the transom but which will still allow the transmission of 35hp of thrust from the prop, through the mounting plate of the leg and into the boat. in other words, i need physically strong sound insulating material. it also needs to be sealable against water.
i thought of sheet lead, or hard rubber, but suspect the former would need to be thick and the latter would transmit vibration.
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interesting comments. i have a prout cat (with a single central engine and a catamaran drive leg) and will be insulating the bay with foam over the winter. however, i already know that a significant amount of noise is structure born, most (i suspect) from the drive leg which is bolted to the transom (ie the prop beat).
anybody know of an insulating material which i can sandwich between the aluminium mounting plate of the drive leg and the transom but which will still allow the transmission of 35hp of thrust from the prop, through the mounting plate of the leg and into the boat. in other words, i need physically strong sound insulating material. it also needs to be sealable against water.
i thought of sheet lead, or hard rubber, but suspect the former would need to be thick and the latter would transmit vibration.
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