Sound Proofing

[paulthepilot_5]

Hi All,

I've just been reading some of the old threads which cover sound proofing of Landys. I was looking at making my own sound proofing material by sandwiching some thin lead sheet approx 1mm, in between some thin sheets of foam rubber. would be alot cheaper than most of the sound proofing products on the market. What are peoples opinions on such a method?

Cheers
Paul

[DEFENDERZOOK]

i would rather use rubber sheets......as they wont absorb moisture like foam does.......

otherwise.....it sounds like it might work.......even on a fender......

[paulthepilot_5]

i would rather use rubber sheets......as they wont absorb moisture like foam does.......

otherwise.....it sounds like it might work.......even on a fender......

Yeah I was sort of thinking using rubber instead of foam. but i think a closed cell foam would be ok


Ha ha Fenders are whisper quiet compaired to my SIII :eek:

[JDNSW]

Hi All,

I've just been reading some of the old threads which cover sound proofing of Landys. I was looking at making my own sound proofing material by sandwiching some thin lead sheet approx 1mm, in between some thin sheets of foam rubber. would be alot cheaper than most of the sound proofing products on the market. What are peoples opinions on such a method?

Cheers
Paul

Strange as it may seem, I am trying this out at the moment. I have made a bell housing muff for the 110 to try and cut out some of the clatter at idle. It comprises a sort of envelope of heavy plastic sheet (started life as an advertising sign) containing an inner layer cut from a hiking mattress about 10mm thick dense foam, and an outer layer of a sheet of lead from some old flashing. It is secured by ropes tied round it every 5cm and passing through eyelets in the middle join and end.

Results are positive so far, but we will have to see how durable it is. Also, there is a considerable gap at the bottom I want to block off, so I will probably rehash it when I get back from Perth.

The big problem with anything using sheet lead will be keeping it in place, due to its weight and structural weakness, but in this sort of position it may well be suitable. I can envision all sorts of problems with it, for example, as an under bonnet insulation.

This sort of insulation acts by blocking the transmission of sound through the foam/lead interface, where it will be almost totally reflected due to the big difference in acoustic impedance.

John

[eddiec]

interesting timing, as I'm thinking similarly - although for cost/weight/convenience i was considering painting a closed-cell foam layer with bitumen paint, then possibly sandwiching another layer... assumes the bitumen paint remains flexible enough.

I was originally considering the bitumen/felt products available, but after leaving the fender out in the gippsland rains on the weekend, the temporary felt in the footwells was saturated enough to make me think twice about anything that holds water...

[Bigbjorn]

Nylex used to make a variety of noise absorption and noise barrier products. Closed cell foam with a reflective foil layer, closed cell foam and lead sandwich, etc. All are used in their appropriate application. I had a fair bit to do with this stuff when the mining coys and unions got fussy about noise levels of mobile plant. Find a source on the internet or yellow pages and ask for recommendations. The foam/lead/foam sandwich was the most effective and most expensive but needed to be in the right places.

[Lotz-A-Landies]

...Find a source on the internet or yellow pages and ask for recommendations. The foam/lead/foam sandwich was the most effective and most expensive but needed to be in the right places.
I don't know how many people watch Foxtel programmes like "Overhauling" but they always use a self adhesive black/silver foil backed mat product called "Dynamat" I think. Am assuming it is some sort of closed cell/bitumen/lead product.

Does anyone know of an Australian distributor?

Diana

[Bigbjorn]

The foil facing reflects sound, the foam absorbs sound, and the lead is a barrier. We found we had to use all three in appropriate places according to the build and nature of the machine concerned.

[shorty943]

Try a marine product called "Sound-sorba".

Used in fancy motor-yachts, to insulate engine boxes etc, it is heat, oil, water-resistant. Comes in a variety of thicknesses, can take to curves, and is glued or screwed into position.

[Lotz-A-Landies]

Try a marine product called "Sound-sorba".

Used in fancy motor-yachts, to insulate engine boxes etc, it is heat, oil, water-resistant.
Shorty

That is exactly the sort of product I'm looking for - in the S2B you sit directly over the engine and wheels with only a 2 mm thick flat sheet of aluminium between. That is why a friend has ear muffs for the passenger.

https://www.aulro.com/afvb/images/imported/2008/05/276.jpg

Unfortunately it's illegal for the driver.

Diana

[Dunnie]

Bias Marine sell the sheet foam stuff. They are marine discount stores who do catalogue mail order if you are not near their outlets. Lots of potential Landy parts in there as well.

www.biasboating.com.au/

[shorty943]

Shorty

That is exactly the sort of product I'm looking for - in the S2B you sit directly over the engine and wheels with only a 2 mm thick flat sheet of aluminium between. That is why a friend has ear muffs for the passenger.

https://www.aulro.com/afvb/images/imported/2008/05/276.jpg

Unfortunately it's illegal for the driver.

Diana


And so it should be. I damn near got run over in Adelaide years ago. Idiot driving a Moke, wearing stereo headphones plugged into his radio.

That is a neat S3 dash in that S2, or am I mistaken again.

[Quiggers]

Noise also comes from drumming, panels which are bare...and vibrate like a drum skin.

If you want to go for the sound recording studio deadening, most studios use Sonex, amazing stuff, flexible, and looks pretty cool, too!

This'll give you a hint: http://www.sonex-online.com/


GQ

[DEFENDERZOOK]

they would be great to stick to the turret of a fender......only problem is.....they absorb moisture....they are a type of sponge.....

[shorty943]

Noise also comes from drumming, panels which are bare...and vibrate like a drum skin.

If you want to go for the sound recording studio deadening, most studios use Sonex, amazing stuff, flexible, and looks pretty cool, too!

This'll give you a hint: http://www.sonex-online.com/


GQ

My, how things change.

I can still remember a school trip to channel nine in Adelaide, way back in the sixties. They were using egg cartons for studio soundproofing in those days.

Probably not water-proof enough for a Landy.:D

[DEFENDERZOOK]

egg cartons will work as well.......


its the actual shape of them that absorbs the sound......
basically......theres no flat surfaces for the sound to reflect/bounce off........
so it bounces around in the valleys and gets broken down till theres nothing left......


sooooo..........the more times you roll your rig and dent the roof and panels........the quieter it should be......

[Offender90]

Here are some notes on sound insulation that you may find useful.

Before I go into details, there are two modes of sound transmission, and one of sound "amplification" The first mode of transmission is airborne and the second structure borne. Ultimately, you must ensure that both are dealt with to get noticable noise reduction in the cabin. In addition the "sound amplification" I'm talking about is the sound reverberation buildup in the cabin, if the cabin is bare / has a lot of exposed metal / glass.

Transmission

Airborne noise is cheaper to deal with of the two, but it is more difficult, given Land Rover's superb door sealing qualities and the multitude of firewall openings behind the trim. However, it should be tackled first.

You'll find this will also help with airconditioning, for those "lucky" enough to have it.

So, before you lay out any insulation on the floor etc, make sure the cabin is well sealed from the the underside (exhaust) and from the engine compartment. This means ensuring all door seals (especially the back door) sit firmly against the door when closed, and that there are no gaps in the seal, especially at the bottom corners, where two different sections of seal meet. As a rule of thumb, if you can see the pavement , it is definately not well sealed!

Secondly, seal all wiring access holes in the firewall. When I say seal, use something like flexible mastic, which will allow movement of the wires without the seal cracking. Make sure the mastic is a skinning type, otherwise you'll end up with a mess. If you're finding that skinning mastic isn't strong enough to hold in place, you could try silicon.

Once you are certain that the cabin is well sealed, you can proceed to insulating the floor to deal with structure borne noise transmission.

Outside noise induces vibration in the floor panels, which then radiate noise into the cabin. The panels will be more efficient at radiating at certain frequencies than at others, depending on the shape, density and rigidity of the panel material. Noise transmission into the cabin will be the worst when the exciting frequency matches the resonant frequency of the panel.

For low frequency engine and exhaust noise, lead sheeting is by far the best. It has a very high density and low rigidity. The critical frequency will be well into the ultrasonic range. If you can line the underside of the car (from either inside or outside) with 1 mm or 2mm lead sheeting, you'll be doing quite well. I'd use a thin foam lining on the underside of the lead so that you don't get metal on metal rattle.

As pointed out earlier, it may be difficult to secure in place - This may have been the reason for lead sheeting with foam on either side mentioned in one of the other threads. I have not gone through the process myself yet, so unfortunately I can't give you too many practical tips. I am an acoustic engineer, however, and have come accross many similar problems in building applications.

Reverberation

Many of the older Defenders / countys and series vehicles have a lot of bare metal within the cabin (in addition to all the glass), so the cabin is highly reverberant (sound bouncing around for a long time, because there is little to absorb it). This results in significant increase in noise levels inside the cabin. I recently bought a Defender 90 panelvan with a stright-through exhaust, and next to no floor coverings - I should know!

This is what I've done so far, and what I plan to do.
I've used high density short pile marine carpet with a rubber backing to line the back area, with noticeably improved results. I also plan to line the rear panels with 50mm polyester batting behind a perforated metal sheet, to help with sound absorption wintin the cabin even more. (admittedly this may be a bit of overkill, but I also think it will improve the looks / practicability of the cargo area.

When I get time, I'll look at sealing the doors and firewall, and then I plan to line the cargo area with 1mm lead sheeting with a very thin underlay. I still have to think about what the impacts of lead in direct contact with aluminium have on corrosion.

Anyone with a son or daughter doing Yr 12 chemistry?? :)


Also, to dispel a common myth, the foil has no effect on noise transmission. It is acoustically transparent, as it has no weight. Silver foil is a great heat reflector, and it is often found on insulating materials because they serve a dual purpose for insulation of both noise and heat.

Cheers

[Offender90]

Forgot to mention windows - these also have to be "sealed" with rubber or silicone strips. Raven makes a great range of both rubber and silicone seals.

www.raven.com.au

Cheers

[DEFENDERZOOK]

are you making fun of us..........mentioning defenders AND door seals in the same sentence......?

[Offender90]

are you making fun of us..........mentioning defenders AND door seals in the same sentence......?

I am engineer, I not make fun, I only say how problems are and challenge :angel:

[DEFENDERZOOK]

the only way to seal up a defender is from the outside........with sikaflex......











and a six inch spatula.......

but then you will have to forget about ever opening and shutting anything such as doors etc ever again........

[shorty943]

Nope, that doesn't stay put for long.

One good swim and there she goes. Sikaflex gone, leaks back.:(

Although enough of it on the inside of panels might stop some of the drumming.

[DEFENDERZOOK]

sikaflex never lets go........the paint or metal or whatever its stuck to will have to come off with it.......

[shorty943]

sikaflex never lets go........the paint or metal or whatever its stuck to will have to come off with it.......


:D:D You've obviously never been down into the Southern Ocean in a timber sailing vessel.:twisted::twisted:

Trust me sikaflex can let go. Had to set up a tarp over my bunk.:(
I was the only one with a dry bunk for 3 weeks.:cool:

[DEFENDERZOOK]

i refuse to take lurch for a three week dunk......

[paulthepilot_5]

Thanks for the responses guys, they have been very usefull :) I will do a bit of looking around at clark rubber and the like, to see what i can find. I think i should put some gaters on the Hi/Low range selector and handbrake lever, at the moment there arn't any (good in winter if u crack the windows open a bit, lots of warm air from the engine and gearbox :p) alot of sound is probably from the holes :eek: I'll think i'll line the firewall with that foil covered 25mm engine room insulation from the boating suppy store. I was also going to put some 5mm thick heavy rubber lining on the underside of the front and rear wheel wells, mainly to to stop mud and sand from building up on everything, I think this would help stop alot of road noise.

[shorty943]

And the footwells and seatbox. With Sound-sorba.

Door linings help as well.

And the idea of rubber valances in the guards is interesting.
I might have a go at that myself, I happen to have come across some industrial nylon sheet, like a kitchen cutting board, but black and solid, might have a play, considering the old girl is undressed at the moment.

[EchiDna]

closed cell foam under the lead will help as it will decouple the surfaces which will further aid in sound absorbance by breaking up the transmission of the sound waves through the layers.

A cheap and fast experiment would be to grab some used ceiling tiles from the office and roughly cut to shape on the floor throughout the vehicle to see what the difference could be like.

That said, ceiling tiles or your typical foam sound insulation soaks up water and water held against the firewall will kill it quicksmart... I know that after removing some insulation installed by a previous owner and finding fist sized holes through my firewall :(

Edit:
how about a thick coating of rhinoliner/hippoliner first, then the closed cell foam, then lead sheet, then rubber matting? any thoughts on this?

[Don 130]

I fitted 10mm self-adhesive closed - cell foam with a aluminium outer skin to the underside of my whole floor and also to the inside of my roof. I got the stuff from an airconditioning manufacturer. Had a good result. Hope this helps.

Don

[Davo]

I've used a few metres of this stuff, called Form Shield http://www.lincolnsentry.com.au/Product.aspx?id=1065 from Clark Rubber. I love Clark Rubber! What a great shop! I actually make it a priority to visit one when we make the rare trip down to Perth.

It's foil-backed, closed-cell grey foam. It comes in two thicknesses. I've got it on the cab side of the bulkhead, about two layers on the tranny tunnel, on the floors, all around the seatbox, and because so much heat and noise comes from the transmission, I even managed to put it on the underside of the seatbox, over, in front of, and on the LH and RH sides of the gearbox. Those bits are against the seatbox surfaces, so that there is still airflow for the gearbox.

It's worked well, to the point where the wife and I can actually have a nice chat with the windows closed. (Unfortunately, the heat up here means we always have to have the windows open! Aircon is on the list.) The floor and seatbase are much cooler, too, so we no longer have the dreaded Toasted-Feet Syndrome.

The next thing is to try making the aforementioned "lead sandwich", which I think will remove the last of the annoying whiny noises.






Though I could always leave the wife at home!

[eddiec]

Thanks Davo for that link. I nicked up to our local Clark Rubber store this weekend and purchased a few metres of that stuff - Was a bit skeptical, as it looked pretty simple, but even though i've only half-done the job, the difference is quite remarkable...

Basically spent the weekend painting the front floor and tranny tunnel (and as much of the firewall as I could reach) with bitumen paint, then covering the tunnel/firewall with flashtac, and then a good solid layer of Form Shield over the tunnel and loose mats on both floors, followed by some marine carpet on both footwells and the original rubber mats back over the tunnel area...

Fired it up yesterday and was amazed. Noticeably quieter (which I hoped for, but didn't really expect), but more importantly all the higher pitched rattly stuff is gone, so what noise is left is a deeper rumble, which is much more acceptable... Makes the car sound more like one piece, rather than several thousand loosly bolted together!

Next step is to do basically every floor/seat surface in the same way. Seatbox, rear floor, under the rear seats, etc., and then another kind of insulation in between the roof lining and the roof when I replace the lining soon...

[TonyC]

As I posted in a another thread.
Another supplier and materal.

The Purple Pig supplies Acoustop sound deadening products as well as almost any industrial rubber product you could want. They have branches in Vic Tas and NSW.
Welcome to Purple Pig (Australia) Pty. Limited. - Industrial Rubber Products Hose and Accessories (http://www.purplepig.com.au/)
Acoustop - Noise Solution Materials (http://www.acoustop.com/products.htm)

Tony

[DefendeRR]

What about that stuff they try to sell you when you buy a new car?

You know, thay come at you with a whole package of Rust Proofing, Window Tinting, bha, blah, AND......Under-Body Sound-Deadening. I beleive its a spray on thick rubbery compound.

Any comments on effectiveness, costs, down sides, and where / cost?

[Ruslan]

Acoustop - Noise Solution Materials (http://www.acoustop.com/products.htm)

https://www.aulro.com/afvb/images/imported/2007/12/408.jpg (http://www.acoustop.com/automotive.htm)

:BigThumb:

[Fusion]

My father-in-law used old carpet on the doors and roof on his 2a and it took out alot of noise . i think he used quik-grip to make it stick .

[LRHybrid100]

A link to my insulation project : http://www.aulro.com/afvb/technical-chatter/50429-d110-insulation-install.html

LRH

[amtravic1]

I have a mate who is a boat builder. Moved to Sydney around 20 years ago so I dont see him much these days.
Anyway, when he was in Melbourne he bought a new combi van, a 2 litre one and he installed some sound proofing he was using in the engine bay of the boat around the engine hump at the rear of the combi van.
It was a vinyl type material with a very thin layer of lead sandwiched inbetween. I can honestly say his combi van was as quiet or quieter than a normal car after he did that. It would be worth chasing the product as it is very effective.

Ian

[Sprint]

I don't know how many people watch Foxtel programmes like "Overhauling" but they always use a self adhesive black/silver foil backed mat product called "Dynamat" I think. Am assuming it is some sort of closed cell/bitumen/lead product.

Does anyone know of an Australian distributor?

Diana

dynamat is available deom most half decent car audio shops, great stuff IMO

a cheaper alternative is flashtac, a self adhesive flashing tape you can buy from mitre 10, but i wouldnt use it for anything except the horizontal surfaces on the floor.....

for the price tho, i'd still use dynamat