Cruisers Forum
 


Reply
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 03-08-2020, 07:39   #1
Registered User

Join Date: May 2020
Location: Kemah, TX
Boat: Islander P40 40
Posts: 5
Send a message via Skype™ to islanderp40
Engine room insulation and positive feed air

Howdy mariners all,

Currently, installing new insulation in the engine room using Sounddown 1'' thick heavy material.

Because of the weight I'm using the 3M 90 that I have tested and is very good strong adhesive.

As may be expected the 3M 90 is something not to be breathed in.

I have on order a 3M painters respirator.

In addition I want to install a 12v blower on the engine room air intake and have it running while I appy the adhesive which must be applied to both surfaces in place.

Close proximity is unavoidable.

I figured I could leave the blower in place when motoring and the positive airflow would be a benefit to the engine especially in hot weather.

Comments, suggestions welcomed.
islanderp40 is offline   Reply With Quote
Old 03-08-2020, 08:15   #2
Registered User

Join Date: Jul 2009
Location: 2020 - Caribbean, currently Grenada
Boat: Amazon 49 cutter, custom steel boat built in Surrey, Canada
Posts: 731
Images: 1
Re: Engine room insulation and positive feed air

Good thoughts on using a source of outside air while spraying the adhesive.

As far as using the blower to supply cool air to the engine, I know there have been posts on this topic before, but I can't remember when. From memory, the consensus was that there are enough air leakage paths to supply the engine with fresh air for combustion. If you want to cool the engine room, you are better off using the blower to remove heated air from the engine room. Of course, this may not be true for your boat, depending on how attentive to detail you are when you install the sound insulation and if any gaps remain.

With that being said, if you have a high output alternator you may want to use the blower to direct outside air to it to help keep the alternator cooler.

Just some thoughts...

By the way, we pulled out of Seabrook marina in 2015. I still wear my Blackburn T-shirts often, and am wearing one now. Cheers!

Steve
steve77 is offline   Reply With Quote
Old 03-08-2020, 17:54   #3
Registered User
 
wingless's Avatar

Join Date: Aug 2013
Boat: 2000 Searay 380 Sundancer
Posts: 948
Re: Engine room insulation and positive feed air

When I moved my New England boat to the tropics, it transitioned from never having heat soak vapor lock, to always having vapor lock after stopping for an hour.

My solution was to install a pair of high volume, thermostatically controlled heat exhaust blowers, sucking from up high, above each engine.

This solution has been 100% effective at the elimination of the heat soak vapor lock problem.
__________________
2000 SeaRay 380 Sundancer Mercruiser
454 MAG MPI Horizon 380hp / Westerbeke 7.0KW BCGB
many cool mods
wingless is offline   Reply With Quote
Old 03-08-2020, 18:10   #4
Registered User
 
Warby12's Avatar

Join Date: Apr 2013
Location: Pacific Ocean
Boat: 43' Ketch
Posts: 409
Re: Engine room insulation and positive feed air

I have often thought of adding positive venting into the engine compartment. Like steve77 says, if you have it, handy to direct it at the alternator, (not if any chance of salt spray though haha). The thing that has stopped me is that if the engine compartment is at higher pressure than the cabin, would we get engine smells into the cabin? Don't know but it always stops me.
__________________
SailToDo, my humble attempt at some YouTube stuff: https://www.youtube.com/channel/UC13...BHNu0kQQc3YTfw
Warby12 is offline   Reply With Quote
Old 03-08-2020, 18:37   #5
Registered User

Join Date: Mar 2009
Location: Southern Chesapeake Bay
Boat: Norseman 430, Jabberwock
Posts: 1,012
Re: Engine room insulation and positive feed air

Quote:
Originally Posted by Warby12 View Post
I have often thought of adding positive venting into the engine compartment. Like steve77 says, if you have it, handy to direct it at the alternator, (not if any chance of salt spray though haha). The thing that has stopped me is that if the engine compartment is at higher pressure than the cabin, would we get engine smells into the cabin? Don't know but it always stops me.
Yes, that is the problem.
ggray is offline   Reply With Quote
Old 03-08-2020, 20:20   #6
Marine Service Provider
 
boatpoker's Avatar

Join Date: Nov 2008
Location: Whitby, Ontario or Bahamas
Boat: Benford 38 Fantail Cruiser
Posts: 4,276
Re: Engine room insulation and positive feed air

Quote:
Originally Posted by Warby12 View Post
I have often thought of adding positive venting into the engine compartment. Like steve77 says, if you have it, handy to direct it at the alternator, (not if any chance of salt spray though haha). The thing that has stopped me is that if the engine compartment is at higher pressure than the cabin, would we get engine smells into the cabin? Don't know but it always stops me.
Two blowers ... intake from one side, output to the other.
Pretty much like venting a gasoline engine compartment.

Safe Ventilation of Gasoline Engine Compartments
__________________
That hysterical laughter you hear as you sail a way in your "new" boat ..... is the seller.
boatpoker is offline   Reply With Quote
Old 04-08-2020, 12:34   #7
Registered User

Join Date: May 2014
Location: So Cal
Boat: Beneteau 38 Nordlund 72, Marquess 55, Jenneau 49
Posts: 494
Re: Engine room insulation and positive feed air

Quote:
Originally Posted by ggray View Post
Yes, that is the problem.
My Engine room like most has an exhaust powered fan and an intake 4 inch hose from the outside. That way your engine room is at a lower pressure then the cabin since you are sucking the hot air out.
Valmika is offline   Reply With Quote
Old 04-08-2020, 12:34   #8
Registered User

Join Date: Apr 2005
Location: ME, TCI, On da boat
Boat: Pearson 323, Tayana V42CC
Posts: 323
Images: 1
Re: Engine room insulation and positive feed air

I have a 4" high CFM tubaxial exhaust fan ducted from the top of the alternator to a dorade and a make up air from a separate dorade to the opposite side of alternator side of the engine lower down. The amount of heat that comes out on the exhaust fan is impressive and it makes a huge difference on how much electricity I use for the fridge.
Scubaseas is offline   Reply With Quote
Old 04-08-2020, 13:32   #9
Registered User
 
CarinaPDX's Avatar

Join Date: Jan 2010
Location: Portland, Oregon, USA
Boat: 31' Cape George Cutter
Posts: 2,603
Re: Engine room insulation and positive feed air

Run the fan for exhaust, not intake. You do not want positive pressure. Also, be certain that it is ignition-protected; you don't want sparks flying from the brushes with the solvent vapor in the air (from the adhesive). My Volvo's installation manual calls for an exhaust fan, and provides guidance for the flow rate - it is a good idea for all engines. Most "marine" exhaust fans are made for clearing the engine compartment for 5 minutes before starting a gasoline engine, and will not last long in continuous use. A good, continuous duty fan can be bought from Delta-T.

Greg
CarinaPDX is offline   Reply With Quote
Old 04-08-2020, 13:43   #10
Registered User

Join Date: Apr 2005
Location: ME, TCI, On da boat
Boat: Pearson 323, Tayana V42CC
Posts: 323
Images: 1
Re: Engine room insulation and positive feed air

I put in a 4" Shurflo "yellowtail" (what it's now called) and it runs anytime the motor is on. It's still good after 12 years/800 hours.
Scubaseas is offline   Reply With Quote
Old 04-08-2020, 15:14   #11
Registered User

Join Date: Sep 2007
Location: Queensland, Australia
Boat: None at present--between vessels. Ex Piver Loadstar 12.5 metres
Posts: 1,286
Re: Engine room insulation and positive feed air

I used to have a motor vehicle brush-less radiator fan that could be switched on when the engine is running. It shifted a LOT of air and quickly. I used it to push air into the engine room, and it exited via 2 stainless steel deck-stepped ventilation shafts that doubled as supports for the cabin roof.

Smaller fans would probably have worked, it is just that this fan was better and cheaply obtained from a wrecker of motor vehicles.
Mike Banks is offline   Reply With Quote
Old 04-08-2020, 15:35   #12
Registered User
 
Cheechako's Avatar

Join Date: Aug 2006
Location: Skagit City, WA
Posts: 22,874
Re: Engine room insulation and positive feed air

Your boat doesn't already have an engine room blower?
I often ran the blower continuously to keep heat out of the boat in the Caribe, or summer.
__________________
"I spent most of my money on Booze, Broads and Boats. The rest I wasted" - Elmore Leonard











Cheechako is offline   Reply With Quote
Old 04-08-2020, 15:54   #13
Registered User

Join Date: May 2014
Location: So Cal
Boat: Beneteau 38 Nordlund 72, Marquess 55, Jenneau 49
Posts: 494
Re: Engine room insulation and positive feed air

[QUOTE=islanderp40;3200533]Howdy mariners all,

Currently, installing new insulation in the engine room using Sounddown 1'' thick heavy material.





Let us know how the insulation worked out over the stock stuff. I was thinking of changing mine out too.
Valmika is offline   Reply With Quote
Old 04-08-2020, 16:13   #14
Registered User

Join Date: Nov 2018
Posts: 430
Re: Engine room insulation and positive feed air

If you’re installing the foam with an adhesive, I would also use some screws. I did exactly this project using adhesive. About 10 years later, the foam itself started to give way. Whole sections would decide to fall off the bulkhead. That would have been bad enough. Worse was that the adhesive and a thin layer of dead foam stayed firmly and solidly on all of the surfaces. Getting THAT off to replace the foam was by far the worst part of the job.
Bycrick is offline   Reply With Quote
Old 04-08-2020, 22:19   #15
Registered User

Join Date: Aug 2007
Location: Adelaide, South Australia, sailing in the Med.
Boat: Beneteau, Oceanis 50
Posts: 786
Re: Engine room insulation and positive feed air

Quote:
Originally Posted by islanderp40 View Post
Howdy mariners all,

Currently, installing new insulation in the engine room using Sounddown 1'' thick heavy material.

Because of the weight I'm using the 3M 90 that I have tested and is very good strong adhesive.

As may be expected the 3M 90 is something not to be breathed in.

I have on order a 3M painters respirator.

In addition I want to install a 12v blower on the engine room air intake and have it running while I appy the adhesive which must be applied to both surfaces in place.

Close proximity is unavoidable.

I figured I could leave the blower in place when motoring and the positive airflow would be a benefit to the engine especially in hot weather.

Comments, suggestions welcomed.
You have negative pressure in the engine bay - otherwise you end up with engine fumes in the cabin.

If you did nothing, the pressure would be negative just from the engine breathing, but that is not good practice. You need at least an air inlet duct (or two) to supply the engine air and aid ventilation.
Then ideally, a blower taking air out of there (one duct out, two ducts in gives reasonable balance allowing for the engine as well. That is typically the way many modern boats are set up.
This gives significant airflow through the engine bay for engine aspiration, cooling and ventilation, while still maintaining a slight negative pressure to ensure the fumes go overboard, and not into the cabin.
David B is offline   Reply With Quote
Reply

Tags
engine, insulation

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Removing Old Engine Room Sound Insulation Adhesive... Suijin Construction, Maintenance & Refit 36 25-03-2018 18:13
Refit Engine Room Insulation. Pelagic Construction, Maintenance & Refit 4 27-02-2013 18:50
Engine Room Sound Insulation Beersmith Construction, Maintenance & Refit 8 25-09-2011 11:34
Engine Room Insulation (Long Question) Zach Engines and Propulsion Systems 21 06-08-2010 18:03
Engine room insulation? Strygaldwir Engines and Propulsion Systems 22 26-11-2006 10:34

Advertise Here


All times are GMT -7. The time now is 15:08.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.