GoneFarrell
Guru
Mako, that's huge! Congrats, and thanks for sharing this project!
Which adhesive for mass loaded vinyl
- Thread starter Mako
- Start date
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If you have answers, please help by responding to the unanswered posts.
If you have answers, please help by responding to the unanswered posts.
Keysdisease
Guru
- Joined
- Apr 15, 2008
- Messages
- 13,738
- Location
- California Delta
- Vessel Name
- FlyWright
- Vessel Make
- 1977 Marshall Californian 34 LRC
Only as a carpet underlayment. Click the link in my post above and the thread describes it and includes photos and measurements.
Keysdisease
Guru
The carpet underlayment has a mass loaded vinyl layer bonded to a medium density carpet pad. The MLV layer goes UP. The pad acts as a decoupler and provides a very plush feel underfoot.
For privacy 1lb MLV alone is typically adequate for walls that abut other cabins or passageways, for walls that abut the engine room 2lb would be recommended.
Of course, if you have a bunch of 2lb on hand, more is better
For privacy 1lb MLV alone is typically adequate for walls that abut other cabins or passageways, for walls that abut the engine room 2lb would be recommended.
Of course, if you have a bunch of 2lb on hand, more is better
Attachments
To followup, I had some remaining material which I applied to the plastic intake box which sits on the carburetors. I assumed that a lot of noise comes through the carbs, which face directly forward to the steering station. Cover the entire box.
Today measured 78db, versus the previous 80db, so it was not much of an improvement. Still rather loud for me, but the only way to get an old 2-stroke quieter is to turn it off!
Ha
Today measured 78db, versus the previous 80db, so it was not much of an improvement. Still rather loud for me, but the only way to get an old 2-stroke quieter is to turn it off!
Ha
- Joined
- Apr 15, 2008
- Messages
- 13,738
- Location
- California Delta
- Vessel Name
- FlyWright
- Vessel Make
- 1977 Marshall Californian 34 LRC
IIRC, a 10 dB reduction is a 50% reduction in signal or noise. If that's accurate, you might have more improvement that it appears. 2dB/10dB = 20%...20% of 50% = 10% less noise. That is significant, IMO.
I may be misremembering the details...please correct me if I'm wrong.
I may be misremembering the details...please correct me if I'm wrong.
@Frosty, yes I did finish the small remaining side areas as well.
@Fly, I think your math is probably correct. I know that sound levels are logarithmic, and logarithmic scales always confused me in school.
I think the conclusion of all this is that even for a small dinghy outboard, it is worthwhile to treat the cowling (even 1lb MLV is better than nothing). This is especially true for a 2-stroke but personally I would for a 4 also.
Don’t get me started on my old Gray Marine Jimmies !
@Fly, I think your math is probably correct. I know that sound levels are logarithmic, and logarithmic scales always confused me in school.
I think the conclusion of all this is that even for a small dinghy outboard, it is worthwhile to treat the cowling (even 1lb MLV is better than nothing). This is especially true for a 2-stroke but personally I would for a 4 also.
Don’t get me started on my old Gray Marine Jimmies !
