Best sound insulation for a one-cylinder Yanmar?

[LakeMurraySailor]

I've got a Yanmar SB12 in my Catalina 30 and running the engine is a headache if you want to go below. The sound will drive you crazy. I even have to put the companion boards in place while in the cockpit. What the best insulation to use? The engine cover was modified to accomodate the taller engine(I believe she came with an Atomic 4 gasoline engine)! It will have to be thin on top! Any and all suggestions would be appreciated.

 

[ggrizzard]

Don't have a product name, but go to a local car audio shop and ask them. They have choices and quality. Also ask about fire resistance rating.

 

[SailormanDan]

I can't find a receipt, but I got some 1ft sq. self-stick stuff that is for marine use years ago that I stuck on the underside of my pull out stairs and it really helped make my Yanmar 1GM much quieter. I think it was about an inch thick. It is heavy, but that is part of the effectiveness of it. Not perfect, but makes the whole thing more tolerable. The other thing that helped was having the cutless bearing replaced, the prop and shaft balanced, new motor mounts, and then everything aligned.
I have a can of rubber spray-on stuff that I haven't used yet for a spot where the self-stick wouldn't hold.

 

[Mark Maulden]

Sailorsolutions.com...worked great. Kinda expensive. Our grandson works at a car stereo shop and i remarked that i dont hear all the stupid bass thumping from cars lately..he said they must be doing their job. I would also check out car stereo places..Flammability might be an issue...

 

[Ted]

Check out Soundown insulation. They have purpose designed insulation specifically for marine applications in varying thicknesses. http://www.soundown.com/Section 1 PDFs/Products.pdf

 

[Dalliance]

I replaced the crumbling 32 year old foam insulation in my engine compartment with this product from West Marine. It's available in 1/2 and 1 inch thicknesses. I used the 1 inch and it's definitely an improvement over the original 1 inch foam. Did the walls, ceiling, and backside of the access panel.
http://www.westmarine.com/buy/west-...arrier-material--P006_180_006_004?recordNum=1

 

[LakeMurraySailor]

Thanks everyone!

 

[woodster]

how far are you from augusta ga....go to morris supply co on broad street....about the twelve hundred block..... iirc..... and get some armaflex foam and adhesive .......that's what i have and i don't know mine is running about half the time if i am not at the stern of the boat

 

[Ken13559]

Cheaper to use ear plugs

 

[kito]

Anyone try that fire resistant foam spray? I seen it at Lowes.

 

[odaydokay]

I did this many years ago. Worked well. I went to a foam fabricator. They buy big rolls and cut it for customer jobs. They were kind enough to sell me what I needed. Key question they asked was what was the exposure? I said mainly gas/diesel fumes at worst (hopefully neither). The asked because one foam type is alcohol resistant (and fails when exposed to petroleum fumes or liquid) and the other is petroleum resistant and they gave me the latter.I guess it is 1-1/2 to 2" thick and has a peaks and valleys texture. I did every area I could get to around the engine.

 

[Justin_NSA]

Anyone try that fire resistant foam spray? I seen it at Lowes.

Interesting idea. If you could build a sort of shadowbox frame, you could spray it in. The frame would contain the foam and then you could shave it flush. Like they do between wall studs.

 

[kito]

I was thinking of just spraying it on the inside of all the engine box panels. I wonder how well it would stick? You would have to experiment with it a while to know how much to spray and see how much it expands. I have a can but haven't used it yet. I bought it for other purposes but thought it may work as sound insulation too.

 

[LakeMurraySailor]

Thanks Woodster(and everyone), you are always right on target! I'm about 65 miles from Augusta!

 

[Scott T-Bird]

It's a sailboat ... trim your sails and turn your engine off. Problem solved. Silence is golden. Aside from that, it would make me nervous if I couldn't hear any unusual sounds the engine may make underway. I took the remaining insulation out, once I saw that it was crumbling. That said, it is a bit noisy.

 

[LakeMurraySailor]

Hi Scott! Great point! I have a short trek to get out of the marina and out into the big water and then free at last(if I could just get that ringing out of my ears)! And besides that sometimes there's no wind and you just have to fire it up! It would also be nice to hear yourself think and of course let the crew hear the Captain's orders!

 

[kito]

How about those windless days and you are just out cruising?. The Admiral is in the cabin cooking vittles and you can't hear her complaining how loud it is? ....never mind

 

[Scott T-Bird]

vittles?

 

[Don S/V ILLusion]

Cheaper to use ear plugs

My initial thought (how to minimize the noise) was judicious use of the ignition key

 

[kito]

vittles?

A Jethro Bodine term, aka.....the double naught spy