View Full Version : Foam on the Firewall Deteriorating

01-08-2012, 01:34 PM
The foam on the firewall in my engine compartment is deteriorating. I guess it would be easy enough to replace but I am wondering if I even need it. Doesn't seem like it could do much to hold down the engine noise. What is it for?

01-08-2012, 02:19 PM
I think it's as you say, for sound deadening. When they built the custom motorbox for my Nova, they lined it with a padding that actually has a metallic layer, that is supposed to filter additionally because it mechanically won't pass certain frequencies well. So it was said, anyway. Curious what others have in their Donzis.

01-08-2012, 05:35 PM
I understand the firewall of the AMH comes out easily, held in by only a few screws.
More important than sound deadening, the firewall supports the deck and keeps the structure in the seat back from cracking. The "bouncing", "trampolining" forces were directed to the hull bottom through it.
I vote for a nice paint job....after you clean off all the old foam.

My TR, being an early OMC boat (maybe), it hasn't a firewall, only the glass seatback. Many of these earlier boats atructure cracked, including the floor.

Dr. Dan
01-08-2012, 06:10 PM
:spongebob: Tim...mine didn't have it...but the hatch had the Egg Crate Honeycomb....foam in charcoal grey... I had bought some ...not sure what condition its in...anymore...I never put it in...after the full repower in 2004 ..the least of my concerns was "Sound Deadening"?

I would leave it off....maybe cut some Brite Diamond Plate and replace it as a cover over whats there..now...you can get the super thin stuff.

I just have painted bulkhead like a starboard...trimmed from the factory in a stainless lip on the top edge.

Danny :wavey:

01-08-2012, 06:13 PM
I have 3/4" sound deadening mat, silver backing on both sides, I recommend it

Carl C
01-08-2012, 08:24 PM
"something else" - fiberglass diamond plate

01-17-2012, 10:48 AM
My '01 also has the fiberglass diamond plate.

The silver faced foam Ghost and Buiz mentioned does work though. It's available in a couple different thicknesses through places like West Marine. It's sticky-backed so you just stick it in place. Comes with a roll of silver tape to do the seams on more complicated installs, and they make mechanical fasteners for overhead attachment. The foam is surprisingly heavy/dense.

On my Carver I was unhappy with the engine noise at cruising speed so shortly after I got it I pulled the deck out of the cockpit and added the insulation to the complete underside as well as the hatches. It made a noticeable difference.

01-17-2012, 12:43 PM
'99, fiberglass diamond plate.