Soundproofing insulation

[robrado974 1]

I have mentioned about the deluxe underlay. You chaps may be ok with OEM carpet?, I can’t say for sure. I bought the new carpet which I think is thicker, or maybe it’s because it’s not 20 odd years old, but I couldn’t move my seats backwards or forwards with the deluxe underlay.

[Keyo 47]

Did you template the old stock insulation ones you got out the car mate ? Think you have to do this as the stock ones have different depths to go round the floor pan pattern. Mine is the OEM carpet chap so not to worried about.

[Keyo 47]

This is the grey cell like material I have in the front foot well that is glued to the floor pan.

 

You can still get them . Mine are fully intact so no need for them. They only came in the front footwells from factory.

 

https://www.volkswagen-classic-parts.de/en/daempfung-5600c3.html

[Storm Warning 0]

Good research 👍 Is this to replace the heavy bitumen/rubber layer between the felt and the carpet? I've not tried to pull apart the factory layer yet but looks a little brittle in places. Do we know if it is the same material or is it an improved one?

[Keyo 47]

So if you want to go for stock for footwells

 

Front

 

Bottom layer x2 grey cell in each footwell (four all together) Partnumber: 321 863 863

https://www.volkswagen-classic-parts.de/en/daempfung-5600c3.html

 

Middle layer

18-20 mm depth insulation

 

Top rubber layer with adhesive backing layer 2mm depth

Part number 323 863 950

 

Rear footwell

 

Same as above but without the bottom grey cell layer.

 

Glue them all together and you have a stock sound absorber.

Edited December 29, 2019 by Keyo

[Storm Warning 0]

Digging around...that product looks like it's the stuff that you put on bare panels, such as floor plan and door skins.

[Keyo 47]

Yes the grey call is the base layer but only in the front footwells.

[Keyo 47]

Sorry I cant vouch for the new rubber material but the old one is about 2mm and the new stuff has an adhesive backing so you can glue the insulation under it I imagine. I've got some aerosol trimming glue Im going to use and the old rubber has nothing wrong with it , just need to strip the old insulation off ang lue the double layer of Heritage deluxe to the bottom of it.

Edited December 29, 2019 by Keyo

[Storm Warning 0]

Pretty sure my original material will be ok to reuse but I'm interested in the new Part No in the name of science I've purchased some of the 323 863 950 (new rubber material) and will have a look and report back.

 

Good research Keyo, need the Wiki up so your findings can be filed 👍

[Keyo 47]

Thanks Storm Warning its not a bad price to be fair.

 

Got to say the factory insulation is pretty impressive with three different layers.

 

Sure the new rubber material might be able to use on the sides of the original floor insulation to fill in any gaps, even under the rear seats etc as its only 2mm deep so I imagine you could fit it to alot of places with ease of installation with the adhesive backing.

Edited December 29, 2019 by Keyo

[Keyo 47]

I actually think what I have been calling a rubber layer is actually bitumen and you heat the layer on the back and then stick the insulation almost like a roofer , could be wrong though. I would rather just use glue as the Heritage stuff looks like hay.

 

I think the new rubber layer is great just a shame it does not come in wider panels as only 250 mm x 500mm .

 

Can see on Storm warnings picture the bitumen where it joins the insulation has been heat

melted to fuse them together.

Edited December 29, 2019 by Keyo

[fla 9]

Be careful when using the bitumen (mass)layer to ensure it's not in direct contact with the floor pan or door skin. It MUST be decoupled using the insulation layer otherwise you amplify the sound vibration, potentially increasing noise. Its purpose is to act as a sound blocker. If you can, stick some thin foam sheets between it and the panel

[Keyo 47]

Sure will FLA it is the top layer so will be cool, I have a heat gun that should do the job and will be able to do it outside of the car for safety. I would also say it acts as a damp proof course. This insulation would have to be hard wearing and the OE stuff certainly was.

 

#

Edited December 30, 2019 by Keyo

[fla 9]

Would be great if you can take some pics of your progress

[Keyo 47]

Would be great if you can take some pics of your progress

 

OK will do chap, the only thing I think needs a bit more research is the middle insulation 20mm as the OE stuff looks better quality- has more of a dense sponge texture then the Heritage stuff.

 

Bizarrely this dutch seller has some new old stock left rear footwell insulation 20mm bottom section in rear as no grey cell in rear footwell. Gives you a good idea of how it looks and you can see some of it cut out to fit round the floorpan pattern.

 

https://www.vagonderdelenhuis.nl/product/demping-voor-bodem-art-nr-1l0863955/

 

Its sort of handy with the heritage deluxe insulation as you double up or single on the layers to suit the pattern.

Edited December 30, 2019 by Keyo

[James. 9]

Be careful when using the bitumen (mass)layer to ensure it's not in direct contact with the floor pan or door skin. It MUST be decoupled using the insulation layer otherwise you amplify the sound vibration, potentially increasing noise. Its purpose is to act as a sound blocker. If you can, stick some thin foam sheets between it and the panel

 

So if I were to apply the theory to all the other exposed places that are not covered (tunnel,roof etc) I should experience a quieter cabin ?

 

I notice there’s a bitumen like pad on the inside of the door skin. Would the doors benefit from the dual layer system you talk of ?

 

Apologies if I’m asking all the “dummy” questions.

[fla 9]

No dummy questions at all James, your ability on the car is far superior to mine!

A lot of the airborne noise comes from the lower portion of the car. Putting insulation in the roof won't really make a lot of difference.

What you could do is to add a sound absorber under all the mass loaded sheets which would reduce noise. The original will now be compressed to beyond its useful performance level.

An open cell dense foam is best to use.

 

The restriction on the doors is basically space. I have simply replaced (one) door foam with some new open cell foam. I would have wanted to add a mass layer but there's no space!

I'll be doing the other panels when it warms up a bit.

[James. 9]

Thanks Hasan. It’s a topic I’ve wanted to cover (excuse the pun) but have always been overwhelmed with the many mixed opinions out there in the wilds of the internet.

 

From what I’ve read today (and please correct me if I’m wrong)the small pads behind the door and on the roof are there to diffuse any resonance on the panels. And that an open cell foam is best for reducing low frequency noise (road, exhaust, engine) But that a hydro-phobic material should be used, to prevent unwanted moisture being retained (and potentially rotting the car from the inside out (a la Alfa Sud).

 

Would you say that the open cell foam is a suitable replacement for the fibre based material under the carpets ?

[fla 9]

Absolutely spot on James. The problem we ha e and most cars of the era is the potential for moisture to finds its way in and degrade any insulation.

The hydrophobicity of the insulation is key which is why a lot of people.opt for cloded cell foam. But by its nature it doesn't absorb any sound and is too low in density to block any noise. So its main (and perhaps only) function is to decouple a 'vibrating' panel from a noise blocker. And mass us the best noise blocker as long as it's not adhered directly to the panel.

[fla 9]

Absolutely spot on James. The problem we ha e and most cars of the era is the potential for moisture to finds its way in and degrade any insulation.

The hydrophobicity of the insulation is key which is why a lot of people.opt for cloded cell foam. But by its nature it doesn't absorb any sound and is too low in density to block any noise. So its main (and perhaps only) function is to decouple a 'vibrating' panel from a noise blocker. And mass us the best noise blocker as long as it's not adhered directly to the panel.

[Keyo 47]

Hi did my passenger side insulation today due to an old matrix coolant leak.

 

I used the old insulation as a template and then stripped the old insulation off the rubber matt. The insulation was only glued on with trimmer adhesive from factory so fairly easy to remove but nonetheless a messy job but did clean up well.

 

It is important that you copy the insulation below the rubber as some layers are single thickness and others double so it sits on the floor pan pattern snug . The Heritage deluxe insulation worked well as it comes in two layers. So firstly stick one whole insulation layer on the clean rubber with aerosil trimmers glue. Second layer copy the original one where it has double layer and glue them together. Fairly easy job to be honest and a sharp pair of scissors will cut through the Heritage insulation. Don't be tempted to make the pads larger as they encroach by your seat rails and will make your seat unable to slide back and forth. You will need to glue the new made up insulation pads to your footwells trimmer glue worked well.

 

Link shows picture of the disgusting old stuff and a example of one of the base templates I cut out. Bottom of album. Hopefully the state of my old insulation pads will encourage you to take this £50.00 job on.

 

https://photos.app.goo.gl/KofL9bRESGSeZJv47

 

 

P.s I recommend at least a few adhesive trimmer cans.

 

https://www.ebay.co.uk/itm/Trimfix-Adhesive-High-Temperature-120-C-Spray-Glue-For-Headliners-Car-Trims/391260834656?hash=item5b18f68b60:m:mYHz7UcBepFHhz42Xykx-6g

 

Also a couple of rear door card clips and sill trim clips as spares as a couple of my brittle ones snapped. All available from Heritage.

 

Part Numbers

Grommet for sill trim clip 191853586D

Fixing Clip for Door Entry Sill Trim 191853577A

Rear door Panel Retaining Clip 823867299

 

My next job is change out the door card membranes that I did last year out of plastic sheeting. I did my golf out of this stuff and it's fantastic . It is like a grey waterproof sponge material from the dealers.

 

x2 door insulation membrane 3A0867201H - cheapest place to get is from the dealers. Install with butyl tape.

 

https://www.ebay.co.uk/itm/GENUINE-NEW-VW-MK2-GOLF-JETTA-FOAM-INNER-DOOR-MEMBRANE-WATER-SOUND-SEAL-FOIL/331074381557?epid=1888321357&hash=item4d159226f5:g:jdoAAMXQWzNSlJ9k

Edited December 31, 2019 by Keyo

[dragon green 5]

A few years ago I insulated my C,(well the rear of it) I used dynamat on the boot area, inner rear wheel arches,rear seat area and front floor, then I used a 1/2” cell foam, (dodo),

Did it make it quieter ? Not really,

BUT what did quieten it was, 1/2” cell foam stuck to the underside of the the parcel shelf,and using two Corrado boot carpets,with all insulation intact

[Keyo 47]

A few years ago I insulated my C,(well the rear of it) I used dynamat on the boot area, inner rear wheel arches,rear seat area and front floor, then I used a 1/2” cell foam, (dodo),

Did it make it quieter ? Not really,

BUT what did quieten it was, 1/2” cell foam stuck to the underside of the the parcel shelf,and using two Corrado boot carpets,with all insulation intact

 

I have a spoonfed deep pile carpet set including the boot and I imagine it helps a little with the sound deadening.

 

With creaks and rattles its worth re clothing some body clips and checking there are no missing damping grommets that the clips go into, my sill trims were missing all the grommets the clips house into.

Edited January 1, 2020 by Keyo

[Keyo 47]

Carried on with the next phase of my insulation renewal toady.

 

I did the door card membrane last year and was not to impressed with the Heritage plastic sheeting, I should of stopped right there and sourced some new stuff.

 

I used this VW grey waterproof membrane this time which is considerably thicker and I imagine also contributes to the soundproofing. Used alongside butyl tape to adhere.

 

Cost £30.00 from dealers for x2 sheets one for each door.

 

Pictures at bottom of album if you click on link. Shows end results and difference in thickness. Please keep in mind Im no trimmer!

 

Door cards fitted on absolutely fine with the new membrane.

 

Yes Dox I gave the window rail that the wheels run in a clean then a lithium greasing whilst in there what a difference !

 

Please note my door sill trims are missing as Im waiting for some VW grommets to arrive to fit in the holes as my old clips were after market and rattling - proper job are clips and grommets to dampen.

 

https://photos.app.goo.gl/KofL9bRESGSeZJv47

Edited January 5, 2020 by Keyo

[Storm Warning 0]

Sorry I cant vouch for the new rubber material but the old one is about 2mm and the new stuff has an adhesive backing so you can glue the insulation under it I imagine. I've got some aerosol trimming glue Im going to use and the old rubber has nothing wrong with it , just need to strip the old insulation off ang lue the double layer of Heritage deluxe to the bottom of it.

 

A pack of the new stuff arrived and had chance to compare it, Dimension wise its about the same length as a front footwell section and about 3/4 of the width. The thickness came in at 1.5mm, VS factory fronts being about 3.4 and rear footwell being 1.7. It is self adhesive and way more brittle - I've not compared the the sections inside the doors, but it does look more like Dynamat type stuff that needs a little warmth to shape, to fit to rigid panel skins. I'm sure you could use as a replacement under the carpets, but isn't ideal. I will reuse the factory rubber, backed with heritage insulation.

 

https://photos.app.goo.gl/fdDAnPwndvfZyygs8

Edited January 10, 2020 by Storm Warning