Lead lining for my genset cover?

[grantgoold]

Anybody on the board used lead sheets to line their genset box? I have seen reports that have lead lined drywall and other lead impregnated materials. I have access to several square feet of lead sheets and was pondering using lead to help with sound.

Thoughts, opinions.....pros....cons...

Thanks

Grant

[H3Jim]

Lead is very effedtive at deading sound waves.  However you should p;robably look at your total design and see if you think the wieght penalty is worth it.  weight is not that much of an issue in a bus, but you don't want to add it if its not going to provide any benefit.

What are the other materials you are using in your sound box?
How thick is the sound box already?
How large are you openings for air circulation?
Is the generator rubber mounted
are there vibration conducdtin wires, conduits between teh generator and elec box?

I made my sound box according the Dick Wright's specs.  When I first installed the generator, I ran it with no vents, no fans, just the generator inside my bay.  Withthe fiberglass door closed tight against the rubbe seals, it was actually a little quieter than my completed product.  Even though I did the folded air ducts, the low frequency sound still comes out of the vents.  Pretty quiet, but you can still hear it.

Point being that unless the rest of your design can benefit from the extr lead, why add it?  Can you do a before and after, say start the generator and run it without the lead in it and again after you put some on?

[TomC]

I used 3/4" plywood for the cabinet and used 1" lead foam from Camping World (probably could have gotton it cheaper elsewhere).  It has the shiney foil, then foam, layer of lead, foam.  Very effective.  While you can still hear the generator, it is as quiet as I could get it.  The main culprit is the intake noise.  Since my gen compartment is tight, I had to mount the air cleaner outside.  I have a intake baffle at the generator, then outside I have a muffler from Dick Wright on the intake before the air cleaner, but I still have that open carburator sound coming from the intake.  Mine is a 4 cylinder-I think this is why most have gone to a 3 cylinder.  Strange as it sounds, the 3 is smoother and quieter than the 4.
At the Caverns a couple of years ago, on the last day I parked in front and across from me was a sticks and staples with a 8kw Onan "quiet" Diesel running.  Needless to say you had to be within 10 ft of my bus before you heard my generator over the "quiet" Onan that was running.
Suggestions for a quiet generator- build the cabinet with 3/4" dead plywood-a dense plywood that Dick Wright has that in itself provides better sound deadening than regular plywood; mount the cabinet on air bags-while mine is quiet, I get vibration through the bus from the generator-and the motor mounts are fine and nothing is touching; use lead/foam insulation on the inside; use a remote radiator with a belt driven squirrel cage blower-you can get the belt driven blower quieter since it runs slower than a similar direct drive blower-and two speeds is suggested-I have two speeds, high for driving, low for quiet night time use; baffle the intake into the gen-should have 3-90 degree turns in the baffles for max quiet; use double exhaust muffler-and mufflers that are made for Diesels.  Gas mufflers can clog up since the baffles are smaller and the soot from the Diesel can clog them up; use a 3 cylinder engine-4 cylinder has built in harmonics that makes them harder to quiet-I know I have a 4 cylinder in mine. 
Remember-there's no such thing as a too quiet generator.  Good Luck, TomC

[tekebird]

there is alot better material in the marine industry than lead foam or lead.
and none of it weighs anything

most of it comes in 4x8 sheets

[H3Jim]

So what would that be? Does it have a name? how can a busnut get it?

[Jeremy]

There is a type of sound-deadening foam sandwich that uses a lead-substitute material - it's like a thick grey plastic sheet - which is cheaper and lighter than the proper stuff. I used lots of it in an old Land Rover once, and it was very effective, though I obviously cannot say how much more effective real lead would have been. As it happens I rescued some pieces of real lead foam (made up of 5 layers, with two layers of lead) from a skip (dumpster) behind a boat builder just a couple of weeks ago. Looked very expensive and should do the job of soundproofing my gen set nicely. (The boat builder builds Oysters incidentally, which are top-end and very pricey custom yachts).

Jeremy

[tekebird]

One was is tyo search the internet.

one I am familiar with is Ultra dB by Glacier Bay

www.glacierbay.com

[tekebird]

they have a sound byte file with demonstration of the difference in a few products and no insulation.

I have first hand experience and do not think the example does the product justice

[luvrbus]

Grant, i used the lead sheets in my bedroom to lower the noise from the 8v92

[prevost82]

I lined my gen bay with Roxul Insulation, it's rock wool, fireproof (won't burn at all) and is a wool so the fibers are not aligned, so so very sound proof. Used chichen wire to holded it in place, and it's veryyyyy quiet. Also used it in the bedroom, lined the firewall on the inside with it.
Ron

[SKIP]

Another source.      http://www.soundown.com

SKIP

[tekebird]

Sounddown is one of the competetors sound bites.  Not sure what the cost differtence is.

[Kristinsgrandpa]

http://www.soundproofing.org/infopages/generator.htm

Ed

[Kristinsgrandpa]

One more.

http://www.defender.com/product.jsp?path=-1|311|302333&id=95982



Ed