ho/oo trackbed ideas

Certainly the foam underlay will give the quietest running and probably the best running as well. The foam base would provide an element of 'give' under the track - just as happens with the ballast of the prototype - and introduces an element of suspension to your rolling stock.

But I think you have to watch out how you use it. If you ballast with granite chips and PVA glue, then you effectively add a layer of concrete to the track base which can nullify any advantages in flexibility and noise deadening. Using a latex type glue, for a start, will leave the ballast with some flexibility, and I have seen some people advocating using a flexible ballast - something like ground foam - to avoid the 'concrete' problem. Iain Rice also recommends using a paper layer between the track and the foam to keep the foam isolated from glues and ballast - basically use paper strips a bit wider that the foam and glue the edges to the base.

I'm just about to try out a paper covered foam base on a 7mm scale layout to see what the benefits are. My layout will be portable and on three baseboards, so I am experimenting at the moment with some form of locating the rail ends at the baseboard joints so that the ends are also supported on foam in some way. Tying the rail ends directly to the baseboard frame in some way would nullify any advantages in using foam underlay.

Jim.

Have you thought about cork tiles. 4mm sanded un-varnished are about a fiver for a pack of 9 from B&Q which makes 1 sq yard. Can be easily cut with a scalpel or stanley knife, you can chamfer the edges. You can cut them to give single or double trackbed etc. Very quiet running.

For straight sections of 00 then you get about 8ft from one tile, less for curved areas. I stuck mine down with B&Q cork tile adhesive (like a strong rubber cement).

Eddie.

12mm trackbed when ballasted would equate to a 3ft plus shoulder, most commercial trackbeds/foam are about 4/5mm about 1ft shoulder.

Now whilst I realise that in reality the ballast can be up to 3ft deep in places, I am not sure how this will look a 4mm model layout.

I would suggest that it may be worth getting some offcuts of ply and track and trying different thickness trackbeds from 4mm to your 12mm then ballasting. I would try pieces of about 8" long, and thicknesses of trackbed of 4mm, 6mm, 9mm, and 12mm. This could be done with on piece of flexitrack or some offcuts.

I accept there is a little expense involved in this exercise, but suspect that in the long run you will gain a massive amount from the experience, and will be able to actually see how the final trackbed will look.

Just a thought, Eddie.

Thank you all for the advice. Will try different thicknesses of ply first followed by the cork tile idea. Could add two pices of cork tile to arrive at 8mm which might be a happy compromise between full size & scale. Maybe 1/2 inch thick/three feet full size ballast might overpower the track but looking at various layouts some sort of proper depth looks better. Also a drainage ditch either side adds to the realism I think. Had not thought about cork tiles from B & Q - I wonder what else they have that could be used. Paper under the track but over the foam sounds good as well - do you think paper could be exchanged for double sided tape to hold the track in place.....

Thanks again

I assume by "track route" you mean shaped (curved and straight) roadbed on which to mount the track formation. If this is expected to span the usual 12" and up bewteen supports, it is much too light, and will eventually sag. Use 1/2" as a minimum. It should be 2.5" to 3" wide to allow for pathways, signal lines, etc along side the track, and space for attaching the scenery skin. It should vary, being wider where you will have a cutting to allow for track-side ditching, and narrower for the top of an embankment.

For the ballast formers:

Cork: It's easiest to use the same thickness both in yards and out on the main, which means it should be about 1/4" thick: ballast is surprisingly deep, especially on modern lines. Ready shaped strip is easiest to use, but if cutting and shaping the ballast slope doesn't faze you, go ahead. That slope should be 45 degrees or less, BTW.

Foamcore board (as used by sign makers, etc): a sandwich of heavy paper or card with plastic foam in between. Easier to cut and shape than cork. Usually cheaper than cork. Comes in several thicknesses.

3/16" or 1/4" plywood: the "mahogany" kind (often sold with one side printed as panelling) is soft enough to take track pins well, and can be cut with a craft knife. There will be splinters, though. The stuff also makes a good base for a control panels.

Softwood, nominal 1" (clear pine, for example): expensive, but if you can rout the edges to a suitable profile, it combines subroadbed and ballast former into one, so will save money. The profile should look like _/---\_

I advise against the foam roll. You'll get a nice dipsy doodle effect. We tried it on our club layout, the consensus was Never Again.

As for ballasting, etc: a) Pin or glue the track in place; b) Add the dry ballast, and shape it using small flat brushes; do not put any ballast in or near the points of turnouts. c) Wet the ballast by dribbling on water with a dollop of isopropyl alcohol in it ("rubbing alcohol".) If the ballast balls up, add more alcohol. d) Dribble on a mix of water and PVA, again with a few drops of isopropyl in it. It should look like there's too much glue. e) Let dry at least 24 hours. f) Remove bits of ballast stuck to the rails. g) Remove pins. h) Paint (a whole 'nother subject.)

HTH

I have used green felt tiles which are designed for under wood floor silencing. They are about 1 x 2 ft and 5mm thick. A dab of wood glue keeps them on the boards and I have had no problems despite my repeated re-designs.mm is after all the 1 ft height typical of many roads. Your ditching would be at some distance as most beds needed at least 3 ft width of ballasting to the sides and even more on fast bends. If you employed ply as you are thinking then a stepped arrangement ( like a mayen temple) would , with a felt base, give all the aspects you wish for.

Peter A

Montarlot

Wolf,

I tried using foam board on a previous layout and I would advise getting all your board at one time from one supplier. I found that the thickness measurement is nominal and you could find that if you got board of an advertised thickness from several sources spread over a period of time, then the boards could vary in thickness which would required packing and ramping to match up two differing specimens.

It also is useless for sound deadening - the structure of the material is quite stiff and the card outer skin acts as a very good soundboard :-)

That could depend of what type of foam you used. The foam I am about to use is supplied by C&L in the UK, is 6mm thick and is quite 'firm'. The recommended glue to attach the foam to wood is a latex glue (or carpet glue, or Copydex) and this glue will not affect the foam, Also, using a paper layer between track and foam provides a boundary layer which protects the foam from any adverse effects from scenic material, etc.

Also I do remember using Peco foam underlay under Streamline way back in the 60s when I dabbled in 4mm, and that did work very well, and I can't remember any problems when using the material.

Jim.

Thanks for the help regarding foamboard. So 1/4 ply sub road bed with say 8mm foamboard on top would work fine but forget about sound deadening qualities.........if I was to add for example a 2mm thick strip of something either side of the foamboard (the strip could be card I suppose) and then ballast the strip and the track - would that look right as a track bed with a drainage ditch either side.....

Thanks for that.