bertram31.com

I have three quick questions regarding the installation of Soundown when I do my repower:

1. Which Soundown product and which thickness?

2. What is the best way to mount it/adhere in the engine compartment?

3. Can I mount things like fuel filters to the forward bulkhead through the Soundown or will that cause damage to or render the Soundown ineffective?

Thanks in advance!

John
I used the 1-1/2" thick Sound Down. I was told by the Sound Down folks that for the diesel engines.....1-1/2" was the minimum they would recommend.

I epoxied wood strips to the hull then used wood battens and wood screws to further secure the S/D around the edges
I cannot remember the part number but you can spray the wall and the S/D with 3M adhesive to make the initial placement.

As far as the mounting equipment on the bulkheads.....once again I epoxied 1-1/2" thick wood blocks to the bulkheads where I wanted to mount the fuel filter. Then cut the S/D to go around the blocks....then sealed over the top of the blocks with S/D tape.

I would not bolt "Stuff" thru the S/D thereby compressing the material.....your equipment will not stay tight and I think you loose Sound deadening when you compress the S/D

One more very important thing......the foil on the face of the S/D is electrically conductive. Be sure to keep electrical equipment very well insulated from the S/D

hb

Thanks Harry!

Just received my sound down in the mail today. Ordered it from Steve at sound down. Went with his recommendation 1 1/2 inch thick in 1lb. I will be screwing it to my forward bulkhead with #10 screws And fender washers (my foward bulk head is now 1 1/2 thick) and using sound downs fastener kit on the hull sides. I will be using epoxy or 5200 to fasten the fasteners to the hull sides.
I will be thur bolting all of my misc. items through the sound down, it does compress but is not an issue. Did the same on my last boat with no issues for 7 years, most installations I have seen bolt through the sound down.
The price was 186 per sheet. 4 1/2 x 8 feet. It was truck shipped to California! WOW WAS THAT A KICK IN THE !!! Not cheap!!
Joe

Joe,

How many sheets total for a complete B31 install? I'm in Northern CA, so I'm in the same boat on the shipping...

Thanks,

John

When I did soundown on my engine boxes, I used the vinyl/foam stuff, rather than the lead/foam stuff. It was easy to use and worked great. I epoxied the sounddown fasteners to the box (the things that look like a nail on a square base), measured and cut the sounddown sheets, pressed them over the nail things, put in the little keeper things, and taped the seams. Its pretty easy. My boxes were heavy enough with the foam/vinyl. I never got to my bulkhead or hull sides. I also found that alot of sound escapes from any open area around the boxes--like if there's a gap by the companion way between the boxes. Once I took care of the gaps, she was really quiet.

My wife has tinnitis so quiet is a good way to preserve family peace. Screaming 300 h.p. Cummins can destroy that peace in a skinny minute. I used two-inch lead-based where possible and the difference was amazing. Made minimal holes is Soundown to accommodate fuel filters etc. Just big enough to get my hands in to change filters. Used their pins and thickened epoxy to fasten. Don't forget the point covers, ouch!
Seal all holes to the exterior as the turbo whine is one annoyance that comes through the cracks.
Measure the square feet of material needed, add 10% for dumbs*#t and have at it. Remember to tape all the edges and seams as you don't want stuff (diesel fumes, dripping antifreeze) getting into it.
Call them with questions, they're good folks.

Thanks for the help guys. One of my biggest concerns is how to keep the noise from the Cummins 6BTA's down to something similar to the noise coming out of a completely uninsulated Mercruiser big block. I know the note and tone are different. However, I'm trying to mitigate as much of that uncomfortable "you mean the exhaust smells AND it's louder?" moment.

Does anyone know if there is enough clearance with the 270hp Cummins remans to get 1.5" Soundown onto the top of the motorbox?

Thanks again!

I used soundown 1.5 in . On top of boxes sides , hull side and bulkhead. Much quieter than the big blocks at idle and cruise. The only bothersome and not really noise is gear rattle at low idle. She...... Read Flag Officer, Never complains

She...... Read Flag Officer, Never complains

LMAO!!!

So how may sheets did you guys use? Getting ready to rip my old 1" stuff out and redue them.

Cannot remember for sure but 8 sheets comes to mind.......you'll have a good bit of waste....

hb

I am using 4 sheets 4 1/2x 8 feet each

From what I remember, the Soundown guy recommended different stuff for the boxes and bulkhead v. the outer hullsides. I wound up only doing the boxes. I remember measuring it and drawing it out on graph paper to minimize waste. Even so, Harry is right, there was a bit of waste. I don't remember how much I used. This is the only picture I could find.