Right now my bus just has plain plywood walls. My buddy really wants me to install carpet on the walls and ceiling to deaden the sound inside the bus. He wants me to get some used carpet and just throw it in. I'm not going with used carpet. That is just nasty. I've told him I don't want to do carpet since we go out to the Black Rock desert (Near Burning Man site) every year and the bus fills with dust. My friend just thinks I can clean or replace the carpet every year and I am not doing that.
I've had a lot of different ideas about interior finishes over the years and I don't think any of them would help deaden sound. My thought has been to install FRP paneling in the rear around and then something else up front. I wanted to do tongue and groove wood, but that is time consuming and expensive.
Any suggestions on any interior finishes that will help with sound? I'm thinking that upholstering with vinyl isn't going to help with sound, but maybe it would.
Anything with a hard finish (eg FRP panelling) is not likely to help much. Wood would help slightly, especially a soft wood such as cork tiles - but a soft upholstery surface is going to be best; vinyl with a foam backing would be easy to keep clean and would absorb sound reasonably well.
But of course the final interior surface finish is only going to make a small contribution to the overall quietness of the bus; if the problem is sound bouncing around inside the interior then it will help quite a lot - but if the problem is the more usual one of sound coming from outside and underneath (eg engine and tyres) then the bulk of the sound reduction needs to be built into the walls and floor.
Jeremy
http://www.soundown.com/index_Marine.htm (http://www.soundown.com/index_Marine.htm)
try these folks
We use upholstery for wall covering in our conversions and underneath it quilt batting. Does a fine job. We do not expose it to much dust etc. Actually vacuum it on occasion. kills sound and adds insulation. Bob
My bus has 2" of spray foam under most of the floor so that probably helps a bit with road noise. I'm not convinced that sound deadening materials with really help with noise. There really isn't that much noise inside except for air leaks up front that I'll probably never solve 100%.
sound board from HD with material or vinyl over it trhen screwed to the walls and or ceiling.
Dave5Cs
Question/ statement.... Upholstery and carpet on the wall does work great as I've seen it on a few coaches we looked at....however I have severe allergies and dust mites live in carpet.....rephrase that....carpet is thier equivalent to a vacation spot......
Like everything we do it is individual. I do understand the carpet especially . Good luck
Wall covering won't help much the noise come from the floors that is why most high bus conversions like Prevost have lead sheets from front to rear fwiw I used lead sheets on the floors in our Eagle conversion but the stuff was cheap then it's still the best for a noise barrier IMO
I think using lead sandwiched in the sub floor is standard on all Prevost, seated models as well because mine has it!
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i did lead over the wheel wells and engine area it helped ALOT. That area in the back bedroom is also the only place with carpet.
Brian,
You have a real problem with the dust issue.
To able to absorb the sound requires anything but a smooth surface.
There are some Ozite type materials you could glue on, but you requirements severely limit your options.
Cliff
As Dave stated in a previous post...
You can go down to home depot and get some sound board and wrap it in some good vinyl. Sound board is engineered just for this. With the vinyl, you won't have the problems with your allergies. You can get many different choices of vinyl to fit your taste. Then just build your panels to fit your walls then wrap them and install them with nice little buttons to match.
After that I think you will need to do something with your windows. Single pane windows are the worst. You will get most of your noise through your windows.
Good luck
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Quote from: DMoedave on May 06, 2012, 10:30:46 AMi did lead over the wheel wells and engine area it helped ALOT. That area in the back bedroom is also the only place with carpet.
Dave, how thick was the lead you used in these locations? Thanks.
The only real reason for sound deadening finishes is to keep my friend happy. I figure if I put stuff like FRP on the walls I might make the sound problem worse than it is now with just plywood. I need to do some sort of interior finish anyhow. Wouldn't Ozite be just as likely to get dirty as carpet? We actually got a lot more holes plugged in the bus this past trip to the desert and the dust wasn't as bad on the way in and out. It still builds up on any flat surface though. I'm thinking carpet or Ozite might not be too bad on the ceiling.
It appears that Home Depots locally don't stock sound board. I found it on the Home Depot website and it is just Homasote. This is the same stuff used for model railroads. I don't think I want to use a paper based product in a bus.
I'm still thinking about upholstering with vinyl. For those that use screws do you then cap the screws? I'm wondering if the 3M Duallock fasteners would hold well enough? They hold 2 lbs per inch.
Quote from: belfert on May 06, 2012, 12:55:49 PM(snip) Wouldn't Ozite be just as likely to get dirty as carpet? (snip)
Brian, I'm not really deep into soundproofing yet but I had had a little experience with Ozite. It's kind of a matter of degrees (in my experience) - Ozite is a lot better than carpet for avoiding showing surface dirt, catching dust, standing up to wear, etc. than carpet but it's much closer to carpet than say, a vinyl-upholstered surface.
Brian:
Sound is composed of many frequencies, both high and low. Most of the materials being talked about will attenuate high frequencies while doing little to the low frequencies. So identifying what type of noise you wish to control will help with choosing the best approach.
Insulation will attenuate high frequencies, the more the better for sound transfer and heat loss. Sometimes just adding furniture, items or "bodies" will knock down noise. Low frequencies are more about vibration and stopping the transfer there of.
I built a recording studio with floated walls and every trick I could find in the sound designers hand book, but underplayed the importance of the ventilation system supply and return ducts being a giant "hole in the walls" connecting everything, so little things can defeat all the greater work and money spent.
Good Luck Gerry H
In a previous home renovation, I used Green Glue to PVC water pipe noise (which happens to be a noise I hate), as well as to attempt to reduce general bathroom sounds. It did an exceptional job with the water pipe noise, and very well with voices. It didn't do as well with certain other bathroom sounds I hoped to reduce. It was probably worth doing, though.
Bruce, not sure of the exact thickness maybe 1/16th. It was shower pan material and i got it from an old plumbing supply that had some rolls with damaged edges at a decent price( most guys use the vinyl pans now). I have heard you can get it at roofing supplys as well.
If you know anyone who installs medical imaging equipment they sometimes can get scrap lead sheet from demolition of old imaging rooms, or scrap from new installs. The guy I know in that business lives 500 miles away so it really doesn't help me.
When installing lead sheet should you put screws or fasteners through it? I always thought fasteners transmit sounds, but I don't know how else you secure whatever covers the lead.
Would some sort of acoustic paint or coating work for the time being? It would be easy to clean and disrupt the reflection of sound. You can also add removable wall hangings that, although do not cover the walls entirely will break up sound wave reflection. Further, you can tell your friend to stop shouting.
I found some sort of paintable wallpaper that absorbs sound, but I have no idea where to buy it. It is a commercial product and only sold wholesale from what I can find so far. It is about 1/8" thick.
I'm thinking about several options. I need to find a place that sells Ozite locally so I can take a look at it.
Quote from: belfert on May 08, 2012, 06:18:18 PM
If you know anyone who installs medical imaging equipment they sometimes can get scrap lead sheet from demolition of old imaging rooms, or scrap from new installs. The guy I know in that business lives 500 miles away so it really doesn't help me.
When installing lead sheet should you put screws or fasteners through it? I always thought fasteners transmit sounds, but I don't know how else you secure whatever covers the lead.
Lead sheet is easily available from builders merchants and the like, but I don't think you would just buy raw lead sheet and attach it to your bus floor; there are all sorts of ready made sound-proofing materials which incorporate layers of lead (or lead substitute) material sandwiched between other materials. Depending on the application you would buy sheets of plywood with lead incorporated into it, or lead sandwiched between layers of foam.
The purpose of using lead is simply that it is a heavy, dense material which takes a lot of energy to make it vibrate - hence it tends to absorb low frequency sounds. If it is sandwiched between layers of foam, any vibrating it does do is isolated and not passed on into the room. The foam is also effective at absorbing the higher-frequency sounds, which get reflected around inside the foam structure.
I have some acoustic material which was spare after fitting out the engine room of a boat, and it is a 5-layer sandwich consisting of two layers of 'lead' and three layers of foam - except the lead isn't actually lead but some very dense vinyl-type material. Here's a couple of photos taken off the web of proprietary wood/foam/lead sandwich products:-
(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fimg.nauticexpo.com%2Fimages_ne%2Fphoto-g%2Fsandwich-panel-wood-foam-thermal-insulation-254063.jpg&hash=b23fb01f9332bc7510ae41326a7a6356c6db574c)
(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fwww.keepitquiet.co.uk%2Fimages%2FPRODUCTS_gallery%2FFOAM%2520LAMINATES%2F2.jpg&hash=30760be2997def63560650903014e351437dcb18)
Incidentally, I don't think using mechanical fasteners can cause any kind of problem; they might transmit some sound, but very little given their tiny area.
Jeremy
Fasteners can definitely defeat the money spent on exotic materials. Anything that aids in the transfer of vibrations should be minimized or avoided. Try an adhesive of some type.
Those sandwhich type isolators are sometimes used on large machining centers and bolted to concrete floors with rubber encased lag bolts. The rubber isolates or impedes the vibration so the bolt doesn't "carry" it through to the floor.
That's true, and I've got my generator mounted on exactly that kind of isoelastic mount - but I don't think you'd try to use them to try to isolate the entire wall or floor panels in a bus.
Certainly use adhesive rather than mechanical fastenings - but I'm not sure that adhesive can be said to have any kind of 'anti vibration' properties, unless perhaps you're gluing the panels down with thick beads of silicone for instance, which might go some which replicates the rubber in an isoelastic mount
Jeremy
Used to do home theaters, so I've used these before, but I'm not associated with them at all...
Glue: http://www.quietrock.com/soundproof-products/damping-glue.html (http://www.quietrock.com/soundproof-products/damping-glue.html)
The guys at "Serious Energy" make a bunch of products you might want to take a look at - sheetrock with damping material embedded, plywood with damping material embedded, acoustic sealants and glues (as linked above). They even have non-gypsum shetrock (no mold/rot).
Think of the planar surfaces as a diaphram, or the surface of a drum. You want to absorb vibration (lower frequencies), and difuse rather than reflect sound that isn't transmitted (higher frequencies). If you have space mineral fiber or "rockwool" in the wall will break up any high frequncies hat get past your first surface. A flat smoth face is likely to reflect higher frequency sound back in to the bus, so something with a textured surface (even like a beaded wood face) will help.
-T
I have used Ozite in several bus conversions with good results. As others have said before, heavy dense materials are the base to stop sound from being transmitted into the bus but Ozite is a great product for the wall and ceiling to attenuate the higer frequencys that bounce around. We typically cover the walls and ceiling with that thin bubble insulation with the aluminum foil on each side called reflectex or something like that. It has been a while but I think we got the last from Home Depot. It adds a small amount of insulation but mainly evens out the seams in the plywood joints so they don't show through the Ozite. Ozite is now owned by the Foss Company, they are great to deal with and will send you samples for colors and various textures. http://www.ozite.com/cprod.cfm?item=cp7 (http://www.ozite.com/cprod.cfm?item=cp7)
I havent bought any in a few years, but the largest roll they sell is about 6' wide and takes two men to carry it but is enough to do the entire ceiling and walls in a 40' bus. Thin contact cement down and spray the glue on with a cheap quart paint gun then throw the gun away. Very quick and easy.
Quote from: Tim Strommen on May 09, 2012, 09:01:41 PM
Glue: http://www.quietrock.com/soundproof-products/damping-glue.html (http://www.quietrock.com/soundproof-products/damping-glue.html)
Interesting...I didn't know there was such a thing as 'acoustic glue' but it turns out that it works just as I guessed - applied with a gun as a thick (3/8") bead of rubbery material between the panels. Interestingly the instructions insist multiple times that the glue is not a 'structural adhesive', and that mechanical fastenings are also needed.
Jeremy
Cheapest most efficient under the floor is mass loaded vinyl I think. I buy it in 48-96 wide roll. 1/8" thick. Roll out between floors. On the walls upholstrey foam with cloth, or vinyl works great. Just my 2 cents!!
Quote from: Ericbsc on May 10, 2012, 03:05:37 PM
Cheapest most efficient under the floor is mass loaded vinyl I think. I buy it in 48-96 wide roll. 1/8" thick. Roll out between floors. On the walls upholstrey foam with cloth, or vinyl works great. Just my 2 cents!!
Florr is already finished so that isn't changing. Does the vinyl really absorb sound? My thoughts right now are oak wainscot on the bottom and some Ozite carpet on the walls above that.
Quote from: belfert on May 10, 2012, 05:23:17 PM
Does the vinyl really absorb sound?
You'll notice that Eric specifically said '
mass loaded vinyl'; this is something else I'd not heard of before (I've learnt a lot from this thread!), but, courtesy of Mr Google, there's now no question in my mind that mass loaded vinyl is the 'lead substitute' material in my layered foam soundproofing that I mentioned earlier.
Jeremy
Quote from: Jeremy on May 11, 2012, 06:34:26 AM
Quote from: belfert on May 10, 2012, 05:23:17 PM
Does the vinyl really absorb sound?
You'll notice that Eric specifically said 'mass loaded vinyl'; this is something else I'd not heard of before (I've learnt a lot from this thread!), but, courtesy of Mr Google, there's now no question in my mind that mass loaded vinyl is the 'lead substitute' material in my layered foam soundproofing that I mentioned earlier.
He said to use mass loaded vinyl for the floor. For the walls he said to use upholstery foam with cloth or vinyl over it. I'm fairly certain he meant upholstery vinyl for the walls.
My question is would upholstery vinyl really help absorb sound?
You're right, he did - my bad.
Regarding the foam-backed upholstery vinyl - I would think that most of the (fairly limited) sound-proofing benefit of this would come from the foam component rather than the thin layer of vinyl on top of it. Foam is effective against higher-frequency sounds as has been explained, although the foam you get behind upholstery vinyl is only 3 or 4mm thick, so is obviously not going to do a whole lot even with those sounds.
You mentioned right at the start that your bus interior has plain plywood walls - is there anything behind that plywood? If not, you'll obviously get a far greater benefit in doing something with the space there than you will get from the final decorative interior finish.
Jeremy
The plywood is screwed directly to the metal framing. There is either spray foam or pink foam insulation in the cavities between the metal framing members.