PDA

View Full Version : Sound deadening floor



VR457
20-11-2011, 10:58 PM
Things to note in deadening interior -

Vacuum and wipe down surfaces first, tape up loose wires.
Apply different types of deadening materials because one type of material will only insulate against certain types of frequencies. With a range of materials you have a better chance of insulating against road noise, exhaust noise and bass induced vibrations.

Ensure the layers are put on big panels where the most vibrations / sound intrusions are likely to occur. Layer up and tap panel until its nice and dull.

When putting foam on, dont make it too thick and remember that the main carpet has to fit back on so leave plenty of play in the corners and sides.

Tape the foam and carpet layers down so they stay where you want them to after refitting.



These are the stripped pics of the interior - note the sparse sound deadening from the factory -

49701 49711 49709 49703

The first layer - Silent Coat bulk pack.

49700 49707 49712

The second layer - Foam! Got it from Dunelm Mill.

49705 49710 49708

Final layer - Heavy duty carpet.

49702 49706 49704

Results and thoughts: Made a lot of difference. Feel cocooned in the car now, the world seems somewhere out there. Bass is cleaner, sound quality is better as less waves diffusing, refracting, bouncing around and cancelling other sound waves. Tyre noise is still present, though at a much reduced rate. Would recommend putting more Silent Coat on the arches, front bulkhead. Floor seems fine though.

Should i have stripped out the old stuff first? I just left it in on the premise that more = better. Some recommend you take it out before putting new material. Do it if you think it will help.

foxdie
20-11-2011, 11:06 PM
Great writeup and pictures, what was the total cost of doing this? Might do it myself :)

VR457
20-11-2011, 11:12 PM
Not a lot. Silent Coat - £40? Foam - £15-20?. Heavy carpet (could use rubber mat / golf carpet) - £20, tape - £5.

Use more first layer than i have though.

Davezj
21-11-2011, 12:47 AM
i am no expert on audio stuff but i have watch a lot of programs on audio installs,
personally from what i have read/watched about sound deadening i would have put somethimg like Dynamat over all exposed metalwork as you don't know what part actually causes the issues. on some cars they have been acusticly tested and know exactly where to put the sections of dynamat or equivilent to ancel out any vibrations and the like. but If you don't know where to put it you have got to put iteverywhere, over evry exposed bit of metalwork. in my old MKII escort it used rattle to buggery so i used bitcha mine roofing felt backing sheet that were great, and looked just like the dynomat installation you see today. but the bitchamin used to make the car smell like a new ly creasoted shed for a while, which was not a bad thing.
but as you have done, the more sound insulation the better. your carpet might be a bit lumpy, LOL. i have never seen foam being used on floor panels like that before, i can see where you are coming from though maybe you are onto something with the amount of faom you have put down.

nice write up though.

VR457
21-11-2011, 12:51 AM
Thanks Dave. Looking at the pictures after a few months is reminding me that i had not put anywhere near the amount of Silent Coat that i should have. I went with the leftovers from doing the doors, which was done properly. When i get time i just might redo it again. It's not that the noise is bad, somehow i want it whisper quiet at 120 mph - no chance with the wind deflectors on!

JamesGC
21-11-2011, 12:07 PM
nice work. ive started the long boring process of sound proofing my pfl legnum too. im only up to the trunk and roof area, but on mine the factory deadening has separated from itself in places leaving pockets of air inside :sad3:, so ill have to remove it all first /wall. i tried using dry ice and freeze spray but it didnt work very well. ended up using a heat gun + chisel + 200L of elbow grease, and citrus solvent to clean up the residue. ive also come across a different type of factory deadening in the rear quarter panels and a third type beneath the automotive insulation (nightmare to remove) on the roof.

Nick Mann
25-02-2012, 11:59 AM
I want to do some of this soon. I have been perusing the bay of fleas for the adhesive matting - does anyone have any specific recommendations? It seems like Dynamat is overpriced to a non educated delinquent like myself.

I was looking at this: http://www.ebay.co.uk/itm/5m-Car-Audio-Sound-Deadening-Proofing-Sheet-NEW-/160637783640?pt=UK_In_Car_Technology&hash=item2566c20e58#ht_919wt_1037

VR457
25-02-2012, 12:28 PM
You hooligan, sorry, i mean delinquent, the material you linked to could be no more than flashing tape. The general idea is a) thickness is king and b) variety is blah blah. So, try a brand like Silent Coat, a decent pack will cost about £80 and then buy things like underlay and foam with high densities.

From what i heard, you should take off the old insulation first, so a heat gun might come in handy.

Davezj
25-02-2012, 12:33 PM
The only thing I can think of is the adhesive is bitchamin based so I would imagine when it is used in area that will get hot, it will smell.
Particularly the trans mission tunnel where the exhaust runs, not so much when you are moving but in stationary traffic it could cause an issue. The only real way to test this would be to buy so and heat it with a heat gun and see if it smells.

The Vee
25-02-2012, 12:40 PM
When I did mine, I got those self adhesive bitumen type tiles from a bodyshop/motor factor supplier outlet. Still not cheap, but less than dynomat. Then other bits I got from a place called Woolies in Market Deeping who supply loads of things for mainly restoring old cars. I'll see if I can find a link.
Here it is
http://www.woolies-trim.co.uk/

Nick Mann
25-02-2012, 05:10 PM
You hooligan, sorry, i mean delinquent,

Oi, I resemble that remark!!

Silent coat is between 2 and 4 times the price of that stuff I listed, depending on the thickness. They both appear to be multi layered and the "cheaper"(!!!!) adhesive matting in the Silent Coat range is only 2mm thick. The expensive Silent Coat stuff is also bitumen based. I'm not trying to argue, just trying to understand why the stuff with brand names is twice the price or more.

Nick Mann
25-02-2012, 05:16 PM
When I did mine, I got those self adhesive bitumen type tiles from a bodyshop/motor factor supplier outlet. Still not cheap, but less than dynomat. Then other bits I got from a place called Woolies in Market Deeping who supply loads of things for mainly restoring old cars. I'll see if I can find a link.
Here it is
http://www.woolies-trim.co.uk/

Thanks Andy. That seems to be just as expensive as Jamils option. I'm not adverse to spending the money if I have to, but my understanding is that you can use over 50 spuare feet doing 4 doors, boot, bulkhead, floor and tailgate. That could involve spending £60 to £100 more than the stuff I linked to above. There's other stuff I could do with that money! :P

Davezj
25-02-2012, 09:15 PM
Thanks Andy. That seems to be just as expensive as Jamils option. I'm not adverse to spending the money if I have to, but my understanding is that you can use over 50 spuare feet doing 4 doors, boot, bulkhead, floor and tailgate. That could involve spending £60 to £100 more than the stuff I linked to above. There's other stuff I could do with that money! :P

Here is a shot in the dark, could you use cork floor tiles or sheet to use as sound deadening.

You can get those very cheap.

1ft square tile 20 for £26

Nick Mann
25-02-2012, 09:28 PM
Interesting idea, Dave. The dodgy cheapy stuff I linked to claims to be a multi-layer jobby that appears to be similar to many of the big brands. It works out slightly cheaper than the cork tiles you mention. Maybe the cork would be good instead of foam or felt?

VR457
25-02-2012, 11:50 PM
I used flashing tape in my last car, B&Q has lots of it for cheap. The deadening was good initially but seemed to lose its quality after six months. It obviously suffered from the heat / cold changes in the car. Plus on warmer days it did smell which i liked but that's another story.

If you really want then try it as a sandwich layer between other stuff. You want mass loading and sound absorption; mixing and matching seems to achieve that.

Davezj
26-02-2012, 12:02 AM
Interesting idea, Dave. The dodgy cheapy stuff I linked to claims to be a multi-layer jobby that appears to be similar to many of the big brands. It works out slightly cheaper than the cork tiles you mention. Maybe the cork would be good instead of foam or felt?

I was only suggesting cork tile as it was relatively cheap and is not bitchamin based, so not likely to smell. But only the adhesive to contend with smell wise.
But it was purely from a smell point of view I mention cork.

Davezj
26-02-2012, 12:08 AM
I put a link up somewhere to a really good site that went into the do's and do nots with regard to vibration suppression, sound suppression.

I will see if I can find it tomorrow. Here you go, it is from Rouch,
http://www.roush.com/Portals/1/Downloads/Articles/AutomotiveSoundAbsorbing.pdf

Davezj
26-02-2012, 11:43 AM
Here is the road noise thread it came from
http://www.clubvr4.com/forum/showthread.php?61746-Road-noise&highlight=Road+noise+leather+rubber

Nick Mann
26-02-2012, 01:09 PM
Point taken, Jamil. I'll look at the Silent Coat and probably go for the cheaper end of their range that doesn't include bitumen.

Thanks for the links, Dave. The scientific paper is over my head. How do I apply the conclusions from that paper to the real world and the materials for sale? It seems to say similar to Jamil - a variety of materials is the best way forwards and mass gain is the best way to make a big difference.

VR457
26-02-2012, 07:41 PM
If you're still reading then this series of tests of common products is worthwhile...

https://encrypted.google.com/url?sa=t&rct=j&q=sound%20deadener%20showdown&source=web&cd=6&ved=0CH4QFjAF&url=http%3A%2F%2Fwww.dctra.org%2Ffiles%2F1974_TR6_ Carpet_Install%2FSound_Deadener_Showdown.pdf&ei=QXxKT-2mIpKBhQfSm4G7Dg&usg=AFQjCNEKbwWgdQhWuXdluvaPogXIDGrzNg&cad=rja

Davezj
26-02-2012, 08:56 PM
Point taken, Jamil. I'll look at the Silent Coat and probably go for the cheaper end of their range that doesn't include bitumen.

Thanks for the links, Dave. The scientific paper is over my head. How do I apply the conclusions from that paper to the real world and the materials for sale? It seems to say similar to Jamil - a variety of materials is the best way forwards and mass gain is the best way to make a big difference.

The way I read it, is you need a material that can accept the sound/noise into in it then be thick enough to absorb the energy of the noise and not let it out the other side.

So yes a mix of material seems the way to go.
The stuff you used to get in old cars was fluffy wading stuck the the chassis with a rubberised backing, which still seems to be the case nowadays. If you pull the stuff of from under the rear seats you see similar stuff.
But I don't know where to get that stuff from, the only stuff I have seen is the stuff that you liked to.
I will have a look at jamil's link to see what available.

wonderwalker
05-04-2012, 03:14 PM
Hi guys,
I think that the best way to do the sound insulation is by doing a so called sandwich. First you put some kind of silent coat cheaper series to take the vibrations that arise form music etc. you put the anti vibration-material directly on the metal and than on top of that you put some thick material for noise insulation. That can be the material for insulation of audio studios or for insulation of air con. vents that one is good too and is a cheaper option of dynamat and silent coat. But don't use the usual tar based tapes because they can't keep up with the change of temperatures
Good luck!

Nick Mann
06-04-2012, 09:43 AM
Vents is a cheaper version? Searching for sound deadening and vents on google doesn't give me any results for automotive products by that name. Have you got a link or a manufacturer/product name that will help me search?

Nick Mann
21-04-2012, 09:08 AM
I have bought 120 square feet of 2mm silent coat. It's the non-bitumen version. I've never spent that much on a product with no real concept of how much I will enjoy the results, I'm keeping my fingers crossed! Plan is to treat any seams inside the car with rust bullet when I paint the underside, then apply silent coat to floor in main cabin, doors, tailgate, then if I have enough the boot floor and maybe a second layer round the bulkhead and wheel arches. I'll have to see how far it goes. I also plan to put some sticky-backed felt on the bulkhead/wheel arches/cabin floor before re-installing the carpet. Fingers crossed I'll enjoy the results of the money and the work!!

adaxo
21-04-2012, 09:41 AM
Good luck and I will wait for your review with eagerly.

VR457
25-04-2012, 07:20 PM
http://www.ebay.co.uk/itm/15mm-thick-rubber-sheet-black-1mtr-x-1-4mtrs-/170819152476?pt=LH_DefaultDomain_3&hash=item27c59d6a5c

Will be trying some of this out in my car. Just need warm weather for it.

Ps: Nick, have you thought of using felting cement on the wheel arch after the underseal?

Nick Mann
25-04-2012, 10:02 PM
Felting cement?

The silent coat turned up today. 40 sheets weighs exactly 2 stone. So I am planning on adding 6 stone in weight to the floor, bulkhead and doors. I have also bought some 10mm felt to put on the floor too, under the carpet - not sure if I have bought enough of that, so I'll see at the time.
http://www.ebay.co.uk/itm/200739630355?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649#ht_4336wt_1270

VR457
26-04-2012, 02:15 PM
5300753007

There is one report online of someone putting it on the inner arches and reporting a huge reduction in road noise. Looks messy though and there were no reports of what temperatures / conditions the stuff can withstand.

Anyhow, the stuff you already have should make a significant impact on noise. The boot area needs special consideration as all noise entering there is amplified to the rest of the car.