cabin engine noise in 16 & 19 c-dory's

oldgrowth

There have been many threads on the noise generated in the cabin on the C-Doryâ€™s without a cabin bulkhead. I have been trying different things to lessen the engine noise inside the cabin. The foam rubber you see on the engine has made a big difference.

I now have to figure out a way of building something that will not interfere with either engine when they are turned or raised. It has to be mounted to the engine and easy to remove. I would like something that can be layered and shaped around the engine but not against it, like lead flashing but much lighter.

Building something really is not the problem, it is, I would like something besides thick foam for the insulation and would prefer something that could be layered in the enclosure.

Anybody know of a good sound insulation material that is light and thin?
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Dave

Doryman · Posted: Sun Oct 07, 2007 6:50 pm Post subject:

How about this stuff, which is used to reduce sound in diesel trucks?

Warren

CAVU · Posted: Sun Oct 07, 2007 7:55 pm Post subject:

Dave there was a post recently about using a plastic called Kydex which is thermo-moldable. Maybe you con fabricate a close fitting cover using Kydex and the insulation mentioned by Warren?

Sea Wolf · Posted: Sun Oct 07, 2007 9:37 pm Post subject:

Dave-

Why not cut your boat in half (again) and add four feet and an inboard engine and a heavily insulated cowl?

Joe.

rogerbum · Posted: Sun Oct 07, 2007 10:03 pm Post subject:

Joe - if he keeps adding feet, eventually the engine will get far enough away that he can't hear it from the helm. Problem solved if ya' ask me.

Sea Wolf · Posted: Sun Oct 07, 2007 10:18 pm Post subject:

TyBoo · Posted: Sun Oct 07, 2007 10:23 pm Post subject:

The stuff you want is called Aerogel.

Jimbo · Posted: Sun Oct 07, 2007 10:48 pm Post subject:

Ever thought about building a bulkhead Shocked

Jimbo

oldgrowth · Posted: Sun Oct 07, 2007 11:00 pm Post subject:

Ken - I remember Kydex being discussed a few weeks ago but until I went on their site, I never realized all the things that can be made with it. It certainly appears it should work and Warrenâ€™s idea for the insulation looks like it would work.

Using the single sided insulation inside the engine cover could also help. I would like to know how thick the stuff is.

Anybody have any ideas on how thick of a sheet of Kydex I would need? I was thinking of a Â¼ inch.
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Dave

tsturm · Posted: Sun Oct 07, 2007 11:02 pm Post subject:

oldgrowth · Posted: Sun Oct 07, 2007 11:09 pm Post subject:

Mike â€“ Aerogel looks like it would work, but is un-available in anything except small granular pieces. I wonder if it would work if several layers of grains were glued to the inside of the engine cover or to a cover of Kydex over the engine.

It seems to me if Aerogel was used it would have to have a protective coating over it to keep it from chipping off. Would it then still have the sound insulating qualities?

Jimbo â€“ adding a bulkhead to the 16 Cruiser is all but impossible and it would make the cabin way too cramped.
________
Dave

dotnmarty · Posted: Mon Oct 08, 2007 10:32 am Post subject:

Here's an alternative
http://www.bose.com/controller?event=VIEW_PRODUCT_PAGE_EVENT&product=headphones_anc_subcategory&ck=0

oldgrowth · Posted: Sat Oct 13, 2007 1:45 pm Post subject:

hardee · Posted: Sat Oct 13, 2007 3:27 pm Post subject: sound canceling headphones

Dave,
I occasionally fly with my boss, and we use headphones with intercom mic's in the plane. Maybe, the VHF's could be set up like the plane set. On the question about Kydex thickness. I'm pretty sure it comes in 1/8, 3/16, and 1/4. It is realativly easy to heat mold and can be worked (cut, drilled, sanded) cold. I don't know about welding, I think not. but it is quite durable. As with a lot of plastics, it may have issues with vibration. Wish you the best with this new project.
Harvey
SleepyC Moon

DaveS · Posted: Sat Oct 13, 2007 7:08 pm Post subject: