Replacing sound-insulation tiles

I'm sure many of you have been faced with the same issue:* the original sound-insulation tiles in our older trawlers are falling off.* I'd love to hear who has had any luck installing some of the new sound-insulation products on the market.* Did you try adhesive-backed tiles?* Did you use mechanical attachment?* Was it hard to do?* I don't mind the sound that much, but I do plan to spend a fair amount of time at the lower steering station and can see where sound insulation will make that a more pleasant activity for me and for my guests.

No answers to date??? Too late now likely but I've used the Soundown decoupled foam with the silver mylar face, 1" thick, to very good effect.

My boat originally had just a thin layer of lead laid over the joists under the plywood sole, then carpet underlay and carpet on top of all.

The engine is right under us so it was noisy.

The first area I did was the engine hatches for a snug fit of the foam around the hatch opening framework. HUGE DIFFERENCE. I continued over several years as time and $$ permitted to do about 80-% of the rest of the engine compartment ceiling. I initially used the aluminum pins that can be purchased but eventually went to a #6FH ss screw with a souple of washers to hold very large aluminum washers or ss fender washers. Amazing how much radiated noise came through the slits and tiny gaps around the hatches.

I know that eventually I will need to start a replacement program for some of the older foam. However the first foam is now approaching 20 yrs old and is still in good condition so I don't consider some of the warnings I've heard about its imminent breakdown to be a serious problem. My eng. compartment may be cooler than many and I'm sure that helps.

Soundown also makes thicker foams and other products that will reduce noise. I'm at the point that the remaining noise is, I think, more structure transfered so will need new engine mounts and newer , quiter engine (not likely soon).

We used Soundown as well on our project. The deck was in poor condition and we wanted a teak and holly sole so we took up the floor to the framing. Before installing the plywood we glued silomar strips (also by Soundown) to the joists. This helps isolate the floor, reducing structure transmitted noise.

The foam of choice was 2" with a vinyl core. I was told there was no difference in performance weather the core was lead or vinyl. I attached the foam with ss screws and fender washers. It has been 11 years and the foam shows no signs of failure.

We don't seem to get any sound through the hatches. I think the silomar helps a lot here. Most of the noise now comes from the chase where the shifter cables, wire harness and hydraulic steering go into the engine room. I have enough left over to insulate the chase but that project has not made it to the top of the list yet.

Soundown is not cheap nut has made a world of difference.

Rob

37' Sedan

-- Edited by Datenight on Sunday 31st of October 2010 06:17:45 PM

-- Edited by Datenight on Sunday 31st of October 2010 06:19:35 PM

Reviving an old topic.
The 32mm soundown (or similar) decoupled foam with a heavy lead/vinyl? layer has delaminated and fallen off the engine hatch. The first layer of foam was still glued securely to the hatch. I found it draped across the engine and the vinyl layer had turned brown and crumbly. I had vaguely thought the engine was booming a bit!

Further inspection showed that all the insulation in the entire engine space had broken down so I've just finished replacing it with the same - only because I couldn't find anything with similar performance at a reasonable (still expensive) price. This is the stuff with silver Mylar on one side.

The insulation was 10 years old so I suppose it's not unreasonable but I wonder if it's the heat or the vibration (shockwaves) that cause the breakdown. Anyone else had a similar experience. Anyway, $500 or so later including adhesive and tape, it's much quieter underway.

What about this sound insulation spray foam?

Silent Running SR1000 Spray Kit

Is it any good? Does it work? Is it a mess? Could this be a viable alternative to installing foam tiles/panels?

I was warned off glueing when I first started buying and intalling the foam.
i think the reason was exactly what you are finding.

The screws and LARGE washers, whether the purchased pins or my adaptation, work better. I have not had any of it fall off like you describe. The slow crumbling yes but not wholesale delamination. I think I went about every 8 " or what ever was close for a neat pattern, adapting as required..

As mentioned twice, tight fitting hatches and sealed wire and plumbing penetrations can account for a lot of noise, and are the least expensive areas to address.

The foams used for noise insulation are open celled, to absorb noise, but also absorb the nasty atmosphere in an engine room. These contaminants are what cause the foam to break down prematurely. The silver facing is a vapor barrier, and it is recommended to tape all edges and seams to seal the foam when installing.

Some suppliers use premium components, cost more and last longer. On the Pacific rim it's buyer beware.

Mass stops noise, if what you are installing isn't heavy, it's just not going to work very well.

The sound "tiles" many Asian manufacturers used will absorb some noise, and thereby reduce a little noise in the engine space and also throughout the vessel. But to stop noise you need mass, like 20 years ago it was lead, today its mass loaded vinyl. These mass layers work best when "floating" between a de-coupler layer against the bulkhead/overhead and an absorber layer towards the engine.

For those with carpeting an acoustic carpet underlayment is easy to install and very effective.

And as Datenight said, an isolation product (an engineered foam) between the framing and the floor will decouple the floor and make a boat much quieter. Combined with good engine room insulation and a floor treatment like a carpet underlayment this is the best noise control available for boats like trawlers.

The spray/trowel liquid damping products work to various degrees for their intended purpose, which is damping structure-borne noise. Most also call for several coats, up to 4 or 5, to be effective. Most of the issues on trawlers is airborne noise, and a structure borne solution just doesn't work well for an airborne problem.

$ 0.02

Keysdisease -

That sums up a guide to noise control perfectly.

The spray is in addition to Soundown, it can catch noise on surfaces you could not cover with sheet material.

I've discovered some 32mm Soundown left over from the original insulation 10 years ago still in the yard, stored indoors. It had broken down to brown crumbs just as the stuff on the boat had.
I thoroughly taped all the edges originally so I don't think combustion products, heat or vibration are the cause. I now believe it's simply age.