Diesel engine bay insulation

[raptorheli2]

Hi all,

I've had to pull the engine out my boat recently (volvo penta d3 190) for maintenance and whilst out I want to upgrade the sound deadening.

I've had a good search around but I can't find anything really similar to my needs easily.

Can anyone suggest what is a decent option for replacing 25mm egg box foam whilst the engine is out? I assume anything will help dampen it compared to this stuff but looking for anyone with some experience before spending.

 

[Greg2]

I replaced the egg box foam on the underside of the saloon floor panels above the engine bay during the winter. Having explored various options I went or Aquafon , which was recommended by ASAP supplies. I used the 27mm on the basis that the 30mm added weight for only a small increase in sound reduction.

The fixings that are supplied with it are pretty poor but I used insulation fixing discs and screws, which worked well. Overall it seems to do a good job.

 

[raptorheli2]

did it make much difference to noise? I could try and put this over the current egg box foam stuff I guess without much penalty.

 

[Alicatt]

I got sound insulating panels in a heavy weight foam with a self adhesive backing to stick to the panels between the engine and the lazarette, for me weight was not an issue as I had to replace all the ballast in the boat and when balancing up the boat the extra weight of the panels would be off set with a very small reduction in ballast.
I got the panels through our local DIY store. they came in 1m x 0.5m size and 30mm thick

did it make much difference to noise? I could try and put this over the current egg box foam stuff I guess without much penalty.

A bit, the noise is noticeably less in the cockpit directly over the engine, I had the eggshell foam before

 

[Sandy]

Have you heard of ASAP?

Marine Soundproofing and Noise Insulation

 

[Mister E]

Dodo mats are used in vehicles but they are heavy.
Vehicle insulation is worth looking at.

 

[Refueler]

My mobo with a 6cyl 170HP lump in has soft sponge like foam bonded to the panels / bulkheads ...

Sound needs that soft style to absorb the sound waves .. stiff egg-box style will not deaden it .. on;y partially ...



Still from the repair video showing the soft insulation ..

 

[vyv_cox]

Have you heard of ASAP?

Marine Soundproofing and Noise Insulation

Their guideline text looks very useful.

 

[Greg2]

did it make much difference to noise? I could try and put this over the current egg box foam stuff I guess without much penalty.

Difficult to assess accurately as there was six months or more between using the boat with the old and then with the new sound insulation but I would say that the new stuff is better.

Not sure if installing over the egg box stuff would add value but if there is room I guess there is nothing lost in trying and in that case the provided fixings might work on vertical surfaces but you would need to get them behind the foam, probably by cutting a + and sliding one in (they are a square plate with a metal rod attached - the plate sticks to the bulkhead and the rod pierces the insulation and a fixing goes on the rod to hold it in place. NB the rods are too long and would need trimming).

I initially got a different type from ASAP and being local to them I opted to pick it up. It turned out to be very heavy and no good for what we wanted (underside of horizontal surfaces) but chatting with their technical advisor he was very keen on the Aquafon and said it was what they are recommending as the best option.
.