Engine room Insulation

[tgreynolds3]

Noise and Heat insulation in the "engine room" needs replacement... Does anyone have suggestions of what to get/where to get for replacement
thanks

[dpenz]

McMaster-Carr carries a variety of insulating materials, and you can order over the Internet, www.mcmaster.com.
For engine room noise, you need a combination of mass to block noise transmission (measured by the material's STC or Sound Transmission Coefficient) and noise absorption (measured by the NRC or Noise Reduction Coefficient).  Basically, more mass = higher STC, thicker = higher NRC.

A lead/foam sandwich is very effective, but is awkward to work with and somewhat expensive.

More practical for our boats would be the vinyl/foam sandwich.  I'd go with the aluminized film or reinforced film, dual layer sandwich with 1" foam and 1 lb/sf vinyl, McMaster Cat No. 54495T59 or 54495T67.  About $7.50 per sq ft.

Check to make sure this isn't too thick to fit in the engine compartment spaces.

The engine compartment is open to the bilge.  I've often wondered what portion of the audible noise is transmitted through that path.  An acoustical quilt might do a lot of good, or a "pillow" or batten made out of acoustical quilting.  I do know that a lot of noise can go through a small opening, so in order to do much good you would have to close off the compartment completely.  Then you would have to treat the ventilation/air intake openings with some sort of baffling.

Maybe that nice rumbling Diesel noise isn't so bad after all :^)

David

[jrupinsk]

I did my engine room last year with 1" foil/foam.  I used clear silicone caulking and stainless screws with fender washer to secure it.  It cut down on heat and engine noise.  This year I did the engine cover on my motorhome.  I have two sheets left over if you're interested $35 each plus shipping [this stuffs pretty bulky]  I think they measure about 32" x 72".  I can mail a sample to you if you want, just let me know.  You can call me at my store at 609-886-2701 for more info.

[Stu Jackson]

Tom

A Message Board Search will take to you July 24 & 26, 2001, Engine Insulation is the topic.  Search under "noise."  More info for you there.