Soundproofing.

[Guest]

Anyone know where I can buy soundproofing sheets for my engine compartment?

Will it make much difference if I stick it to the hatch itself?

Any advice or ideas greatly appreciated.

Thanks

Andy Coggin

 

[roger]

I'm getting some from Halyard. The other I know is Technix which is priced to look cheaper but excludes VAT and packaging. Halyard gives good advice. - Ask them your questions.
Dont forget you've a lot of noise sources
engine itself - airborne
engine - structure borne
exhaust
Which is cusing the problem?

 

[PeterGibbs]

Halyard do a good range of panels. There are others. They are not cheap (£20-25 per 1 sq metre panel) but then the eggboox type proofing used by some boat builders in the past is almost useless. New panels have to be fire retardent to meet current safety specs (think of insurance etc)

The secret of these panels is that they have a dense sound-absobing layer about half way sandwiched beteen foam bearers. The layer absorbs the airborne energy that is sound. Some panels have double layers embedded for greater sound proofing but they are thick, not easy to install in smaller yachts and costly. The standard 1 1/4 inch thick panel will give a good measure of sound insultation.

Sound seeps out of the compartment like smoke: so all appertures have to be closely panelled or baffled - ie air intakes cannot be closed, of course, so set up baffles that allow air movement but inhibit sound transference.

Do not bother with the space under the engine etc - this cannot be proofed.

Use a good contact adhesive and then screws (with washers to prevent ripping out)
to prevent panels falling into moving machinery should they become loose. And sometimes the heat they face means they do.

Inspection panels should be proofed as tight around the opening as possible. Panels should be held in place by pressure bolts to inhibit as much sound from escaping as possible.

If your engine is noisy this is a good investment. Don't forget to put a water baffle in the exhaust pipe (Vetus is a good source) to compliment the engine compartment sound proofing!

PWG

 

[Guest]

Thanks for the reply. do you have a number for Halyard?

The main problem I have is that without the carpet down the engine hatch seems to act as a large speaker for what going on inside. I have soundproofing on the bulkhead wall, but none anywhere else. I was thinking of putting some on the underside of the hatch in the hope it might soak up some of the sound.

Regards

Andy Coggin.

 

[Robin2]

Re: Soundproofing - another question

As the hulls in my catamaran are narrow the sides of the engines face the sides of the hull.

Is there any value in putting acoustic material on the sides of the hull (i.e alongside the engine) - the noise through the sides will surely be delivered to the outside?

 

[superboots]

If you don't want to pay over the odds for a branded product and can wait until end of April and can get to the Beaulieu Boat Jumble - there is a guy there who sells sheets of closed cell foam as used in the aerospace industry. You could add a lead foil to this to up the spec further. If you have enough space above the engine you can insulate the underside of the hatch. Mine was glued and then overlaid by chicken wire... Bless you Mr Moody! But make sure the stuff is flame and fume proof - experiment with a sample and don't cut off the air supply to the engine

 

[gunnarsilins]

There is a value...

...soundproofing the hull sides. Apart from the fact that less of the sound will be distributed to the outside, you will decrease the amount of internal sound reflections inside the engine room and thus reduce the sound reaching the accomodation.

I my engine room, which is under the deckhouse sole and goes over the entire beam of the boat I made an experiment and put some spare sails in their bags along the hull sides.
There was a slight, but noticeable reduction of sound inside the boat! Obviously the sails absorbed parts of the sound which otherwise would be reflected and find its way in to the accomodation.
So I plan to make some permanent sound absorbers and fit them along the hull sides. Keeping spare sails in the engine room does not appeal to me...

 

[jfkal]

http://www.halyard.co.uk/

Great stuff. I put it on the hatch as well. Makes a great difference.

 

[oldsaltoz]

G’day coggin.
Air intakes are a major cause of noise and the fitting of a simple DIY baffle can make a huge difference. Just make sure it won’t burn; my engine draws it’s air from an intake on the engine cover box. I made a simple baffle from sound proofing foam stuck on some fibreglass off cuts. The ‘box’ was then mounted on the inside of the engine cover and a flexible hose connected it to the air cleaner filter intake. Tip, make the box 3 times larger than the air intake; the baffles can then take up two thirds of the available width in the box giving you a good overlap. (Boy I wish we could draw in this forum), anyway, you finish up with baffles mounted on two of the 4 walls. I can only hope you understand this without a drawing. I can e-mail a drawing if this is a bit confusing.

Avagoodweekend Old Salt Oz……

 

[dickh]

ASAP supplies stocks soundproofing - Tel 01502 711680 - In Beccles, Suffolk - will send by mail order - good people to do business with.