What's the best sound proofing material?

[koukouvagia]

I'm sure I've seen a discussion about this before, but I can't find it.  There seems to be a wealth of advice online, but I can't decide which is the best material to use.

The 1.8 BMC which drives the hydraulic motor is inside a frame and will  have a ply casing. 

 

 

Edited April 7, 2017 by koukouvagia

[WotEver]

You need mass to stop the low frequencies and a labyrinth to stop the high. Mass is generally provided by a lead-like sheet and the labyrinth is provided by foam. 

Products such as this offer both types of sound-deadening. https://www.asap-supplies.com/soundproofing/soundproofing-sheets/quietlife-slimslab-sound-proofing-801834-1

It's not cheap

[NB Lola]

We used a hospital silencer plus the sound proofing sheets wotever linked.  But our engine is a modern canaline 42 which has some sound management value. We can run the engine and few know it's actually on, including walkers passing by.

[Robbo]

You may find this test article useful..

https://www.nkgroup.co.uk/wp-content/uploads/2014/06/Marine-Soundproofing-YM-article.pdf

[Neil2]

You are going to vent that cocoon I presume?

I agree first you need mass then you deal with resonance, the old lead lined foam sheets were best but I don't think you can get them anymore, TW Marine sell a reasonable substitute.

I still reckon for most folk the best bang for buck when it comes to quietening a engine is the biggest silencer the engine will cope with.  Hospital grade silencers are amazing though I think some engines may struggle with the back pressure?  I have a hospital silencer purely on the strength of coming down the Kennet with a couple some years ago who had one fitted to their Thorneycroft 1.8.  That's all they had done plus some foam under the deck boards and it was virtually silent.  

You can also kill a lot of the noise (from vibration) with a proper flexible drive to the prop.

If I was starting from scratch I would go in order of priority hospital silencer, Aquadrive (or Python Drive), then soundproofing.     

[NB Lola]

16 minutes ago, Neil2 said:

You are going to vent that cocoon I presume?

I agree first you need mass then you deal with resonance, the old lead lined foam sheets were best but I don't think you can get them anymore, TW Marine sell a reasonable substitute.

I still reckon for most folk the best bang for buck when it comes to quietening a engine is the biggest silencer the engine will cope with.  Hospital grade silencers are amazing though I think some engines may struggle with the back pressure?  I have a hospital silencer purely on the strength of coming down the Kennet with a couple some years ago who had one fitted to their Thorneycroft 1.8.  That's all they had done plus some foam under the deck boards and it was virtually silent.  

You can also kill a lot of the noise (from vibration) with a proper flexible drive to the prop.

If I was starting from scratch I would go in order of priority hospital silencer, Aquadrive (or Python Drive), then soundproofing.     

Agree with the above but I would suggest  proper prop shaft orientation first.  When we had our engine fitted about 6 years ago we were careful to ensure good alignment and this had an excellent effect in terms of vibration removal.  This is still the case and the engine mounts are still in good alignment.  Combined with the silencer and insulation, effect as mentioned before.

[koukouvagia]

9 minutes ago, NB Lola said:

Agree with the above but I would suggest  proper prop shaft orientation first.  

29 minutes ago, Neil2 said:

You can also kill a lot of the noise (from vibration) with a proper flexible drive to the prop. 

This engine has an hydraulic drive, so this is not relevant in our case.

22 minutes ago, Neil2 said:

You are going to vent that cocoon I presume?

Yes. there'll be adequate ventilation.

[alan_fincher]

8 minutes ago, NB Lola said:

Agree with the above but I would suggest  proper prop shaft orientation first.  When we had our engine fitted about 6 years ago we were careful to ensure good alignment and this had an excellent effect in terms of vibration removal.  This is still the case and the engine mounts are still in good alignment.  Combined with the silencer and insulation, effect as mentioned before.

KK's BMC 1800 drives a pump, which drives an hydraulic drive in the butty rudder, so there is no shaft drive involved.

[alan_fincher]

12 hours ago, koukouvagia said:

I'm sure I've seen a discussion about this before, but I can't find it.  There seems to be a wealth of advice online, but I can't decide which is the best material to use.

The 1.8 BMC which drives the hydraulic motor is inside a frame and will  have a ply casing. 

 

 

 

The dense foam sheeting with the heavy lead like layer in undoubtedly the best stuff, but the different variants available are far from equal.

It's some years since I fitted stuff to Chalice, so the situation could have changed, but back then the stuff supplies by TW Marine was vastly superior to the Aquafax supplied stoff the chandleries were selling.  The foam was far better quality, and the embedded lead like layer very, very much more sunstantial.

Not particularly cheap, but probably trivial compared to what all the other work on Hampton must be costing.

Am I correct in remembering it is raw water cooled with a wet exhaust?  If so, I guess a hospital silencer is not an option?

 

[Bee]

That's a really interesting installation, is the prop going to be mounted on the rudder? As far as soundproofing goes you have not got a lot of room around the front of the engine and the 1.8 is a clattery old thing ( perhaps that's just because all the ones I've known were knackered) . You might find that double skinned wooden or aluminium panels filled with foam or rockwool work ok. Not very scientific but when I drove a terrible old Albion lorry years ago a big heap of blankets chucked over the engine cover worked quite well. (I wonder why the British lorry industry fizzled out)

[Neil2]

24 minutes ago, alan_fincher said:

 

The dense foam sheeting with the heavy lead like layer in undoubtedly the best stuff, but the different variants available are far from equal.

It's some years since I fitted stuff to Chalice, so the situation could have changed, but back then the stuff supplies by TW Marine was vastly superior to the Aquafax supplied stoff the chandleries were selling.  The foam was far better quality, and the embedded lead like layer very, very much more sunstantial.

Not particularly cheap, but probably trivial compared to what all the other work on Hampton must be costing.

Am I correct in remembering it is raw water cooled with a wet exhaust?  If so, I guess a hospital silencer is not an option?

 

I bought some soundproofing from TW Marine last year and Nick mentioned that they no longer sell the "real" lead lined stuff I think he said it's been "outlawed" by some regulation.  The stuff they now sell uses some other compound which is still quite heavy and I agree better than the fare you find in the average chandlers. 

 

[koukouvagia]

 

1 hour ago, alan_fincher said:

It's some years since I fitted stuff to Chalice, so the situation could have changed, but back then the stuff supplies by TW Marine was vastly superior to the Aquafax supplied stoff the chandleries were selling.  The foam was far better quality, and the embedded lead like layer very, very much more sunstantial.

Not particularly cheap, but probably trivial compared to what all the other work on Hampton must be costing.

Am I correct in remembering it is raw water cooled with a wet exhaust?  If so, I guess a hospital silencer is not an option?

 

Thanks for that.  I'll contact TW Marine and see what they have to say.

Yes.  It's a wet exhaust, so I can't fit a hospital silencer. 

It is indeed costing quite a bit. However, as usual, the work of WFBCo (Stockton Dry Dock) is most impressive.  Hampton is now about to have the back cabin fitted out.  Then it'll be painted in the pre 1920s livery. Hey Ho.  Carpe diem and all that.

We were hoping that it would be ready for Braunston, but I think its first public showing will have to wait till Alvecote.

1 hour ago, Bee said:

That's a really interesting installation, is the prop going to be mounted on the rudder?

A bit off topic but here's a picture of the hydraulic drive motor in the rudder  We've had this installation working very successfully for many years.  It was the rest of the back end and the wooden cabin that were quietly rotting away.  Hence the major reconstruction job.

[IanD]

The Quietlife 2 Quiet 45mm from ASAP has two layers of the dense barrier material and should give more isolation than anything else, if you can afford it and fit it in.

[Bod]

Can't help with sound proofing.

Looking at the engine installation photo, how easy/difficult is it to change the fan belt?

Or to get to the front pulley for servicing?

 

Bod

[koukouvagia]

3 hours ago, Bod said:

Can't help with sound proofing.

Looking at the engine installation photo, how easy/difficult is it to change the fan belt?

Or to get to the front pulley for servicing?

 

Bod

Each of the steps can be removed by undoing two bolts.

The alternator belts then can be reached by taking off the cover (next to the third step down) - another two bolts

The whole end of the frame can then be removed if access is needed for the water pump / fuel pump etc.

The engine cover and frame are designed to be completely dismantled if major work is needed on the engine.

 I'm very pleased with the ingenious design by Graeme at Stockton Dry Dock to access the engine.

[koukouvagia]

I just thought I'd report back on the sound insulation I fitted yesterday.

I went for this https://goo.gl/2ANVVn   Not cheap, but remarkably effective.  I used a decibel meter app (probably not brilliantly accurate) and found that the reading before insulation was 80db.  This went down to an impressive 52db.

I like noisy vintage engines, but a 1.8 BMC is rather unpleasant - hence the sound insulation.

 

Edited November 26, 2017 by koukouvagia
picture added

[alan_fincher]

Don't know about anybody else but the JPG image won't open for me.

But looking at what you have used, I very much doubt you would have found anything better, (or at least not at an astronomic price).

How did you attach it?  When I did something similar I used humongous amounts of Evostick.  I'm not sure I have ever been as "high" at any other time!

[koukouvagia]

3 hours ago, alan_fincher said:

Don't know about anybody else but the JPG image won't open for me.

But looking at what you have used, I very much doubt you would have found anything better, (or at least not at an astronomic price).

How did you attach it?  When I did something similar I used humongous amounts of Evostick.  I'm not sure I have ever been as "high" at any other time!

Don't know why the image won't open for you.  I've done nothing different this time.

ASAP supply aerosol tins of industrial strength contact adhesive.  The spray pattern can be adjusted so that you get a 2" wide  line of the glue - all very clever.  I just had to make sure I positioned the sheets correctly first time because the glue was fierce.

Where the sheets were attached to the lid, I screwed on large plastic washers. Seams were closed using a sticky-back metal foil tape.

[alan_fincher]

3 minutes ago, koukouvagia said:

Don't know why the image won't open for you.  I've done nothing different this time.

I just get a tiny icon in the middle of an otherwise all black screen.

[ditchcrawler]

2 minutes ago, alan_fincher said:

I just get a tiny icon in the middle of an otherwise all black screen.

Same

 

[WotEver]

8 minutes ago, ditchcrawler said:

Same

And me

[koukouvagia]

17 minutes ago, WotEver said:

And me

Not sure why.

Here it is again.

 

[tomsk]

Not working for me either.

I would avoid boatyard/chandlery suppliers at all costs.

They will only be sourcing from your local Builders Merchants and applying Profit and Overhead.

 

[Robbo]

Oh shiney.

[WotEver]

20 minutes ago, koukouvagia said:

Not sure why.

Here it is again.

 

Ahah! That works