Budget friendly engine sound insulation.

[rwidman]

Originally Posted by BillKny

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One issue with most boats is that sound can "escape" from a well insulated engine room through even the tiniest holes. Doing a partial job is almost not worth the trouble......

This is an important point.

[George_SD]

But there is more to it than just the pure engine noise transmitted by air waves through the openings. Changing the tone of the noise can often be a positive change since certain frequences are more annoying. Adding insulation with suspended mass or high density (like butyl) can help reduce rattles caused by transmission of vibration to doors, latches or other adjoining parts.

Cheapest methods are often the least beneficial. For example the carton crate foam that is installed in many boats is only about 1" thick (at the narrow point) and does produces some, but very limited benefit.

Adding heavier, thicker or specialty made products in addition with sealing the compartment should produce very significant results. I'm personally very interested in reducing some of the vibrations on panels around the engine and reducing noise at least partially. The quality of life difference between 80db->70db->60db is significant, even though neither can be described as "Quiet".

I was thinking to try butyl based barrier on the engine enclosure surfaces to give some weight and density and then add some foam based layers on top for muffling the actual diesel sound.

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[GILow]

Originally Posted by George_SD

...

I was thinking to try butyl based barrier on the engine enclosure surfaces to give some weight and density and then add some foam based layers on top for muffling the actual diesel sound.

Interesting idea.

[Artey]

For right or for wrong - after reading many a topic here on CF I opted to go with VCT tiles then covered by HVAC fiberglass board and sealed with HVAC metal tape. it has done an okay job for sound deadening and heat insulation. Probably not the best outcome but it was better than the crumbling black suit from the old stuff and was cheap enough I would do it again.

The VCT tiles are heavy and mimic the same concept as lead sheeting, the fiberglass board provides necessary insulation as my ice box butts up against a bulkhead of my engine compartment. Poor design by the mfr.

[GILow]

Originally Posted by Artey

For right or for wrong - after reading many a topic here on CF I opted to go with VCT tiles then covered by HVAC fiberglass board and sealed with HVAC metal tape. it has done an okay job for sound deadening and heat insulation. Probably not the best outcome but it was better than the crumbling black suit from the old stuff and was cheap enough I would do it again.

The VCT tiles are heavy and mimic the same concept as lead sheeting, the fiberglass board provides necessary insulation as my ice box butts up against a bulkhead of my engine compartment. Poor design by the mfr.

Another interesting and lateral-thinking idea.