Outboard Acoustic Insulation

[Whoops]

Hi - I have recently bought a Jeanneau Rigiflex 4m with a Mercury (badged) Tohatsu 30hp two stroke (2001) ...Seems to be a very good combination. Only problem is the amount of noise from the engine at slow speeds...Does anyone have any experience adding acoustic insulation inside the cover of their outboard...Any feedback on results...Good idea / bad idea...Ideal sheet thickness / fitting tips etc. would be much appreciated

[Nos4r2]

Probably a silly question but is there actually enough room inside the cowl to fit extra sound deadening material without it interfering with operation?

[AndrewH]

Good point Nos

Also worth mentioning that the performance of many acoustic foams drops of once the pores start getting filled. Given the amount of grease present inside most outboards, I'd suggest this is going to get smeared all over the foam and therefore pick up all sorts of muck and grime.

Absorbing foams work reasonable well in the engine compartments of larger boats as there is plenty of space to keep grease away from the foam, but as Nos says, space is not a luxury you have under the cowl of an outboard.

If you do decide to try it .. let us know how you get on. Oh, and welcome to the forum by the way

[codprawn]

You may be better off trying it on the outside of the cowl. Someone on here had a very nice neoprene cover made for their outboard - just make sure air can get in!!!

The best sound deadening stuff is lead - you can get some sheets that are self adehsive - they wouldn't take up too much space inside a cowling.

http://www.noisekiller.co.uk/sound_p...ehicles_01.php

[quappo]

the mats i know are often coated with bitumen on one side. There should be no problem with heat and grease. The mats are under 5mm thick and should easiliy fit into the cowl. Personally, I wouldn't disfigure my outboard with some sort of condom :-)

[Whoops]

Thanks everyone - nice to get a response and appreciate your comments...Your thoughts match with some of my own...The insulation sheets I've seen are thin and foil coated - and would seem to be able to fit and deal with the heat / oil / grease etc...But my main concern that I don't want to start sticking stuff inside the cover for it to either not work, bugger up the engine, or if it needs to come out, leaves a gluey mess...Not sure about the external cover...Although we do have an old douvet and some lead sheet left over from some building work - If throw these together, lob them over the engine, and drive about Chichester Harbour like a Laura Ashley advert, do you think it would damage my on-water cred?

Any more views much appreciated. Thanks