Closed cell foam for trackbed

[bordercollie]

Hi
I have been searching the forum for thoughts on what to use for the track bed base. It seems that cork is favoured by many, probably the majority. I had a leaning towards the closed cell foam method. However, many people seem to disregard it due to, amongst other things, that it will disintegrate with time.There are several product options eg exactoscale. but it is not always clear what type of Closed cell foam is being talked about. I see that there are 4 types and I suspect the types used by railway modellers are polyurethane and EVA. I am wondering if people who have used either for an extended period of time eg 10 plus years could comment. It would be helpful to know under what conditions climate etc. they used or stored the product. I personally bought a small amount several years ago but didn't get round to using it and it appears to have remained in perfect condition. It is the EVA type and has been stored in the house.
Best wishes

[bobwallison]

Part of my layout uses Exactoscale foam which has been in place for about 7 years and shows no sign of disintigrating. One of the sheets is unused in a roll and is as tough and flexible as the day I bought it.
Other parts of my layout use Plastazote, which seems to be just as good and durable, although that has only been in place for about 5 years.
The layout is in a loft, semi insulated and free from damp. Temperature has varied from 9°C to 40° C over the period.

Bob

[alan@york]

I built sections of track about 12 years ago, on a cheap camping mat. Hasn't fallen apart at all, but possibly because I left the Templot printouts in place, exposure to UV/light would not be as high.
Sorry, can't tell you which type of plastic was used, it was so cheap it wasn't identified, then.
A@y

[jon price]

Plastazote is polyethylene foam used by museums to make liners for acrylic boxes to hold items from the collection. It is archive safe as far as chemical emissions go, and is durable for the forseeable future. It is durable against most chemicals you are likely to be using, and will show only slight degredation after being buried for 32 years (which is as long as it has been around). So if you use it don't use aggressive industrial solvents, and dispose of the debris properly.

[stephenfreeman]

Here you go

https://www.efoam.co.uk/closed-cell-polyethylene-foam.php?gclid=CjwKCAjwqLblBRBYEiwAV3pCJsaSz7nPo0m-KD9Tu76uF-QuZhZtq7izWzgeSHladrGLK0fPmPbSTRoC7OMQAvD_BwE

All you probably need to know including prices and sizes. I find the self-adhesive option very useful though of course it costs a little more but the time saved is worth it to me.

[Winander]

I looked at this a few months ago and concluded that DCC Concepts trackbed sheets 300 x 600 x 3 mm made from EVA https://www.dccconcepts.com/product/trackbed-sheets-3mm-600-x-300mm-10-pack/ was the most economical way of buying in quantity. I even looked through all the internet foam specialists I could find.

No connection, not even a customer yet.

[grovenor-2685]

My calculation says that the DCC concepts price is rather more than the e-foam co price, and e-foam reduces with quantity.

[Jol Wilkinson]

DCC 1.8 square metres £19.95
eFoam 2.0 square metres £11.99

I have used the latter on London Road when I built the extension baseboards eleven years ago and it shows no sign of deterioration and am using more on the new baseboard. The original baseboards from the mid 1980's used the same/something similar and also are still good.

[Winander]

Jol, you have priced 2mm thick, but I take your point as 3mm is only £14.86. This is for PE foam not EVA like DCC Concepts so strictly speaking not comparing like with like. I had decided to use EVA but found it difficult to source. As you have used PE successfully, that will do for me.

I'll get me coat.

[bordercollie]

Hi
I have done a bit more research.
It appears that polyethylene consists of ethylene only.
By adding various amounts of Vinyl acetate(VA) you get low (up to 4%), medium (4-30%) and high VA EVA. In general the higher the VA content the more flexible. Low EVA has properties very similar to low density PE.
They are other factors but I don't want to disappear down a rabbit hole. All this doesn't really help in deciding what properties would be best for model railway use.
Regards
Graham