Engine soundproofing

[massnspace]

We are considering buying a pilothouse sailboat.

If we do so, I would go to great lengths to soundproof the engine room as best as humanly possible.

My idea: Strip out and organize area, clean thoroughly, paint surfaces with that weird stuff that supposedly turns sound into heat, then finally glue on thick lead-lined insulation pads. (I though it was lead or something…)

Any ideas? Other options?

David
Seattle

[skipperpete]

I’m not aware of any paint that turns sound into heat but , living in a warm climate I probably wouldn’t use anything that makes the inside of the boat hotter. There are some really excellent soundproofing materials on the market and the rule is that thicker is better and a layer of dense material should be sandwiched between layers of non inflammable sound absorbing foam with a thin foil or mylar skin on the engine side to keep the whole lot dry and oil free. This insulation is heavy and glue alone can’t be relied up to keep it where you want it, ideally it needs to be mechanically attached or held to the machinery space walls and bulkheads as well as glued. Stripping out the engine room to install the insulation is obviously the best approach but it can be a daunting task.

[coopec43]

David I looked at this some time ago.

Don't forget you need to ventilate the engine room as motors require lots of air.

I chose not to use lead because of the cost and weight,

I worry about lead shielding in a confined environment: is it toxic?
https://blink.ucsd.edu/safety/occupa...shielding.html

[GordMay]

What skipperpete said!

I’ve never used it, but, “soundproof paint” sounds too good to be true.

As the thickness and/or weight, of a sound barrier are increased, the accoustic performance of the material also increases.
How much sound attenuation should we expect, from a lower mass application, that is only 30-40 thousands of an inch thick?

Mass Loaded Vinyl & Foam Composite [MLV]* insulation combines acoustic absorption and barrier properties, to create a comprehensive treatment for engine rooms and machinery enclosures. Most conventional MLV sound deadening products are ½" to 4" [2" often recommended for engine compartments] thick.

* eg: “Soundown” ➥ https://8ked2d.p3cdn1.secureserver.n...m-2010.1.A.pdf


A custom search, of the Forum, will return numerous previous threads, where the issue of "Engine Soundproofing" has been discussed, in detail.

[coopec43]

Originally Posted by GordMay

What skipperpete said!


A custom search, of the Forum, will return numerous previous threads, where the issue of "Engine Soundproofing" has been discussed, in detail.

Gord
I agree with you 100%



1++++!

[skipperpete]

Originally Posted by massnspace

We are considering buying a pilothouse sailboat.

If we do so, I would go to great lengths to soundproof the engine room as best as humanly possible.

My idea: Strip out and organize area, clean thoroughly, paint surfaces with that weird stuff that supposedly turns sound into heat, then finally glue on thick lead-lined insulation pads. (I though it was lead or something…)

Any ideas? Other options?

David
Seattle

Well, I’m just about finished insulating ( soundproofing) both engine spaces.... hard to call them engine rooms when they’re under the galley on one side an a workbench on the other. I’ve learned a few things while doing this that might be useful.
I partially did what you suggested and removed fuel filters, sea strainers, vent ducting and coolant expansion tanks but built around the domestic water pumps and stuff like that..... this took a lot of time but was worth it once I got the glueing and edge taping technique sorted. I used 2 different adhesives, Bear contact cement and artificial grass adhesive if I needed time to locate the various panels of Soundown, the green adhesive is slower to grab and hold while the contact adhesive is sudden death touch and grip. I got around this by applying the contact adhesive to the foam and then covering it with clingwrap... like the stuff used to cocoon luggage at airports. Once covered , the panel can be bullied into place and the clingwrap progressively removed as the contact is made.
On the subject of adhesives , I was surprised by how many 1 litre tins it took to coat 2 full rolls of soundown and the surface it had to be stuck to, in total 7litres and probably one more before I’m finished. The other surprise was how much edge and seam tape I needed, and that stuff was expensive. All of the overhead panels were glued and then attached with self tapping screws and plastic washers, the original panels had long ago fallen off leaving a very thin layer of foam and the adhesive and I didn’t want to risk that happening again. The domestic water pumps are now very difficult to hear and I kinda miss that hum and the silence that follows, I always knew instantly when a tank was empty..... now not so much!
I tried stanley knives, box cutters and scissors to cut the soundproofing but finally settled on using a wavy edged bread knife and I reckon an electric carving knife might be even better but never tested this theory. The best part of the new insulation was how much brighter the reflective surface makes that previously gloomy unlit space, even a little flashlight gives the place an ET look.
Final tip..... ventilation!!..... while you’re using the contact cement...the fumes are a bit trippy.

[coopec43]

Have you looked at relvannt threads on this forum?

https://www.cruisersforum.com/forums...rchid=37346009

[Montanan]

Recommendation:

https://acoustiblok.com/