Rubber sound insulation advice

Last year at Dortmund fair I saw these which was quite interesting:





The rubber ones are all double sided stickey so when ballasting you do not have to go through that arduous process of glueing. Acoustic sound proof they claim it to be.

Problem is I forgot the name of the manufacturer. . Geting old I guess.

Baykal

*** Cork still works fine and many use it but most use it because they read about or saw someone else using it, not because of any particular virtue. There are many things like this in the hobby - done now because they were done that way long ago - it doesn't make them wrong but it does make it illogical sometimes, especially when more modern materials now exist.

It certainly makes no sense at all to me to lay cork onto rubber... when rubber itself will do the job better than cork.

* Cork directly reflects any imperfections in the baseboard, which closed cell foam does not.

* Cork should therefore be sanded before tracklaying to even out bumps which foam will easily accommodate with no negative effect to track laying surface.

* Cork transmits more noise to the baseboard than Closed Cell Foam as its denser.

* Cork is dearer by a considerable margin... which is widening as cork is not in plentiful supply globally.

* Cork is harder for most to cut and lay well (this may or may not be the case to a skilled modeller, but looking at many of the layouts posted online including MRF, the cork roadbed is often carelssly cut and laid).

*Closed cell foam is available pre-cut with correct 60 degree shoulders which is the correct angle of repose for ballast, so can more easily represent prototype track laying practice. Cork is not.

* Both lay easily with PVA Glue, but Closed Cell foam is easier to lift after laying and so is more easily recycled (either to adopt changes, correct errors or use on a new layout) with perfect results than Cork, which is mostly a write-off.

* Foam is easier to cut and splice for pointwork while preserving the shoulder and shape...

Regards

Richard

I've been experimenting recently with a 3M product which is a grey, closed-cell self-adhesive foam with peel-off backing so has adhesive on both sides. It comes in either 2m, 10m or 25m rolls x 1" (26mm) wide and 2mm thick. A 25 m roll costs about £7 but I have just tried the 2m length on my double track programming track.

It certainly seems to have excellent acoustic insulation properties and seems to be an ideal N Gauge track bed material though possibly not quite wide enough for 00 gauge. I'm sorry I can't be more precise on its trade name as I used the whole 2m roll on my programming track but will try to get more info if anyone is interested.

If using cork or wood floor underlay I would recommend Copydex as an adhesive. It is latex based, so stays soft and flexible, and you have plenty of time to position the track bed while the adhesive is still 'wet'.

QUOTE (neil_s_wood @ 5 Jan 2009, 04:42) <{POST_SNAPBACK}>I find it interesting what has been said about cork as years ago when starting my first layout I went into Hearnms Hobbies to buy loads of foam underlay and was advised by an experienced modeller who works there that foam wasn't really suitable for the Australian environment as it degraded quickly. I used cork ever since.

I have found a cheap source here in Melbourne. Clark rubber used to sell it for $5 a square metre, or at least they did when I laid my track a year or so ago.

***Peco foam was / is indeed unsuitable, but its a totally different animal. This is what I mean by habits being perpetuated - all synthetics were lumped into the same bin because of one modellers habits or because one brand was inadequate.

We aren't talking classic low cost sponge type "foam rubber sheet" as per Peco but closed cell foam - it has a very slightly textured top and bottom surface but that surface is literally "closed" meaning it will not absorb liquid.

Its cut edge has a very fine cellular structure but each "bubble" is also "closed", meaning that its firm-ish so good as a trackbed but remains very resilient due to the springing of each "bubble". It really is fabulously easy and nice to lay and work with compared to foam.

If you buy the higher quality stuff (as I use in our own trackbed) it has a 10 year UV rating - its actually used to make swimming pool covers so that will give you a good idea of its "weather durability". I would be willing to bet it'd outlast cork in many places.

If you want to do some looking at characteristics, look for info on "EVA Foams" (The Military use them a lot for things like cold weather sleeping mats, insulation on all weather systems etc - they are really tought)

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** TIM - an equivalent 2400 x1200 x5mm thick sheet of high quality closed cell foam sells here for approximately $AUD 40~$45 or GBP. Thats about GBP20 for 2.8 square metres.

Pre-cut trackbed with 60 degree shoulders is appx $A60 for 100 linear feet - still not a bad price as its accurately cut, curves naturally/easily to about 30" radius and is also part split underneath in case you want to make tighter curves easier to make and is very efficient - wastage is nearly zero, re-usability is dead easy too, as soak it in detergent and water and any old glue and ballast will come away easily, eaving the original stuff ready to use again.

Tim - If you want to try it send me your street address via EMail to the work address and I'll send you several lengths to experiment with...

Regards

Richard