Generator sound blanket

In the next couple of weeks I will be installing a small DC generator (Ample Power) in my engine room. I know it will be noisy, even turning 1800 rpms, so I'm thinking about ideas for a sound enclosure. Anyone have experience making / using a lead-lined blanket to enclose the genie? It's small -- 30" x 16" x 16".



-- Edited by nwboater on Thursday 16th of February 2012 08:49:45 PM


-- Edited by nwboater on Thursday 16th of February 2012 08:50:41 PM

Be mindful of cooling. While the engine is, I assume, water-cooled the generator itself*is (usually) not. A tightly fitting blanket-type shield might cause problems in this respect. You might be better off building a simple rigid enclosure designed to give you access to the things you need to check or service that also provides for some air space or circulation inside the enclosure.


-- Edited by Marin on Thursday 16th of February 2012 08:55:10 PM

I had a fine sound enclosure for my generator, but when I needed maintenance like changing the raw water pump, it just got in the way.* I removed the enclosusre blankets and I really don't think the enclosure made that much of a difference.* Now, since it is a Westerbeke it is loud as Hell anyway so nothing will mask the noise and removing it in my case was a good idea.

A friend has one of the DC units, Not Ample Power, but the same idea. One lung Kubota driving a~150A alternator. It's actually not bad. It can be heard outside as a putt, putt and inside but it is not obtrusive.

May be worthwhile to take a wait and see attitude about the internal noise particularily if some attention is paid to isolate the unit from the hull.

I agree about a blanket causing a problem with the alternator.

No experience with building a box like that but I have used the 1" decoupled foam to can some of the engine noise. It does work and work well.

Just consider how you will gain access to the unit for mtce and repairs. McMaster Carr offers some interesting latches, toggle type and others which may be of use to you for quick access panels. Even the use of 1/4 turn fasteners, can't remember the name but often used in race cars for secure but quick access to the mtce areas.

Keep in mind that any holes through the enclosure will allow a lot of noise to escape, even a small hole, so barriers and baffles need to be considered.

Look up Soundown Corp. for information about the foams and hints.

C lectric wrote:
. Even the use of 1/4 turn fasteners, can't remember the name but often used in race cars for secure but quick access to the mtce areas.

Click to expand...

*They're called dzus fasteners.

Or Camloc

you might be able to use this materias
http://info.acoustiblok.com/acoustiblok-products/l

btw amplepower has some interesting options for battery charging and also high output alternators and regulators.
http://www.amplepower.com/products/index.html

nwboater wrote:
using a lead-lined blanket to enclose the genie? It's small -- 30" x 16" x 16".

Click to expand...

*Is your gen already enclosed in a box I have seen many that are.

Lead is the most effective sound proofing you can get.5/32" of lead is equivalent to a cinder block wall 6 blocks thick.

Build a plywood box around it and line it with a 32nd of sheet lead you can get it at roofing ( used for chimney flashing) supply or sometimes plumbing supply outfits.

It will quiet things down I guarantee.* I used it on the hatch covers to my engine room.*I then encased it all in a layer of fiberglass so I know mine is safe. Made ahugh difference.

I've looked around on line regarding lead poisoning as long as you don't eat it. It isn't an issue. If you are worried about it check out Soundowner they carry a lead sheathing for just such a purpose.

The idea is if you box it in there isn't any worry about a blanket getting in the way.

SD

*

*


-- Edited by skipperdude on Friday 17th of February 2012 02:35:48 PM

Everyone, thanks for the feedback. Maybe a combination of your ideas...a simple frame mounted to the generator base with lead lined panels fastened to the frame with easy-off fasteners. Guru, I will look at lead flashing...a similar product was*used in*the engine box in my first (wood) boat. Also, good suggestion about isolating/decoupling the*mounting hardware from the hull. I will update you all when this project gets underway*-- rs*

My genset has a tubular frame around it. the blanket has a top and sides that are velcroed to each other with access panels held on with velcroe to check oil, change filters, etc. The frame allows air movement around it. You might check with a Kohler dealer; what you want may be sitting on a shelf somewhere
John
390 Mainship

Simple lead sheeting is not as effective as the decoupled foams. I have lead sheet under the plywood sole in my boat and the foam made the noise tolerable. Yes the lead helped but the foam did more. The older foams actually used ground lead as the decoupling and dampening layer but the foam absorbed the sound.
Use both for the best effect of course.

Go modern,,

www.videoworks.it

FF,

What in the world does that site have to do with sound blankets?

They offer sound suppression equipment for engine rooms for large charter tubs.

And the concept is reduced NOISE!

REnt a 60 meter boat , and who wants to hear engine sounds?

Advantage , no creations of leaded sheets to disassemble to see the noisemaker , and quieter underway with the main engine(s).

Update re: sound blanket for genset. The little 6hp genny (12VDC unit) has been operating in my Willard engine room since last summer. No need for a sound blanket! It operates at between 1800-2000 rpms and is reasonably quiet. The little Kubota diesel is belted to a large frame alternator and puts out between 80 to 110 amps under load and does a good job charging the house bank.

Good to know. I'm in the process of installing my little DC generator and hope to get it running next week. I got mine from AquaMarine. It's been quite the ordeal getting it installed. Everytime I start on another aspect of the installation (mounting, exhaust, fuel, electrical), I find I need something I didn't think about. What are you using for a regulator?

Ron

Ron, Like you, I thought installing my genny would be a simple weekend project. Not! For an external regulator, I choose the Balmar ARS-5 (http://www.balmar.net/PDF/regulator info s/ARS-5.pdf). The important feature is that it allows the generator to "soft ramp" gradually instead of taking on a full load immediately after starting, and of course, it provides the full range of charging cycles. However, I recently read where someone argued in favor of a simple single stage regulator; since our little gensets will never be used to recharge the battery bank to 100% capacity (80% is more realistic). So why bother with a multi-stage regulator. Instead, regulate the charge to stay at "flood" until the bank reaches 80% then shut it down. Interesting perspective.

So why bother with a multi-stage regulator. Instead, regulate the charge to stay at "flood" until the bank reaches 80% then shut it down.

This was done "way back" with a big wire wound resistor replacing the VR and the operator would regulate the charge rate.

Worked quite well with the 60A (maybe 45A hot) car alth used at the time , 1960's.

"T Mac" might google the schematic.

Dumb or lazy folks could boil the batt set , so the next evolution was the "Auto Mac".

nwboater said:

Ron, Like you, I thought installing my genny would be a simple weekend project. Not! For an external regulator, I choose the Balmar ARS-5 (http://www.balmar.net/PDF/regulator info s/ARS-5.pdf). The important feature is that it allows the generator to "soft ramp" gradually instead of taking on a full load immediately after starting, and of course, it provides the full range of charging cycles. However, I recently read where someone argued in favor of a simple single stage regulator; since our little gensets will never be used to recharge the battery bank to 100% capacity (80% is more realistic). So why bother with a multi-stage regulator. Instead, regulate the charge to stay at "flood" until the bank reaches 80% then shut it down. Interesting perspective.

Click to expand...

Thanks, the Balmar ARS-5 is the regulator I bought but I haven't started installed it yet. I need more electrical parts. I will explore using a single stage regulator as what you say makes sense. I'm taking the long trek over to Fisheries Supply tomorrow to get what I hope, are all I need to complete the installation.

Thanks again for the tip.

Ron

I have plans on constructing an insulated plywood box (with suitable inlet/outlet vents etc) around my 6.5 Kw Phasor genset. I have seen these latches (pic) holding the panels together on Onan sound shields. Anyone know what they are called and/or who sells 'em?

Toggle latches. There are numerous styles. They can be found in the McMaster Carr catalogue and possibly Grainer. Both have website catalogues.

Also punch up Amico toggle latches and several styles will come up on Amazon

Toggle latches?

Thanks guys, just what I needed - prices are a pleasant surprise too!