A discussion on underlay...help please :-(

[LastLine]

Hi All,

First post here, and asking for advice so hope that doesn't seem cheeky!

I'm currently relaying my OO/HO DCC layout and have read that laying track on top of sponge underlay such as that available from Hornby is advisable, but I have to ask why?

I've found that finding pins to go through the track and then the underlay into the board is quite tricky, not impossible but tricky - minor issue I know, so sorted it with a bit of a hunt.

My main issue is the points motors, I've gone out and bought the new points motors (surface mounted for what it's worth, the new small black ones - R8243) and this is where the problem really gets me. The underlay raises the track off of the baseboard - obviously. But what is my answer for my motors? There doesn't seem to be one that allows the motors to work very well at all.

So this got me to thinking - what's the point of underlay? Is it purely to dampen the sound of the train running on the board? If not what else?

If there is actually a good reasont to keep it, is there any reason I couldn't just lay my entire baseboard with something such as a thin polystyrene ceiling tile which should offer less noise, and allow my points motors to be mounted on a level with the track points. Has anyone tried this and found any huge benefits or alternatives to it?

I'm at a loss here but would love to hear people's views as it's got me a bit baffled half way through my construction and I don't really want to carry on until I've got a solution for it.

Any help greatley apprecited.

David

[lukee]

Well I thought the point of underlay in real life was to hold the track steady. It's composed of small stones. Sorry if this sounds patronising but it's just incase you meant underlay generally rather than just foam. I was also wondering about pinning down the track through foam. You could also use scatter underlay material, but I think the foam just makes the job easier, and more cost effective. I suppose the point of it on a layout though is just to make it look more realistic. :)

[LastLine]

Yeah I'm more looking at practicality for a model layout rather than a 'real life' layout. I just can't find a solution to the points.

[lukee]

Well they make seperate foam moulds for points, and I'm sure with a craft knife you can cut a hole through the bottom of the foam to fix on a motor. :)

[Bengunn]

Hi, David,
Just joined today - and found your query which is one I have just been working on! Basically, a sponge 'underlay' a) helps to deaden the sound-box effect of trains running on bare wooden baseboards, b) it forms a suitable base on which to lay and glue your ballast grit, c)outside of a station goods-yard, etc, it can be shaped to give the raised trackbed seen on main line stretches and, d) if - like me, you use magnets under the track for uncoupling, a 6mm underlay accommodates the 6mm thick magnets without having to make holes in the wooden tabletop.

I use 6mm thick 'EVA medium density' which is a smooth, firm, foam sheeting coming in various colours (I use a dark brown) and thicknesses, the latter ranging from 2mm upwards. A firm called A.ALGEO Ltd (www.algeos.com) produce it for the footwear industry. I glue the foam to the table with PVA, either in a sheet (for station yards, MPD's, etc) or in strips cut to shape for track beds. Once stuck down, the track is then glued to it in the same manner, but with the addition of light ballasting, etc, before it dries. The ballast can be improved upon, later, with a 'top dressing'!

With pointwork I mark out the position of the pin which actuates the tie bar, prior to the gluing, and drill a single hole through both underlay and table. Using this hole I can position the motor beneath the table and screw it in place, then remove it and cut a slot either side of the single hole to accommodate the sideways motion of the pin. Once screwed back in position the points can be placed in position with the tie bar over the pin. One point to ensure, though, is that NO GLUE goes onto the underlay where the tie-bar sits! (this can be embarrassing!)

Since I use PCB for sleepers the wiring of the layout is made simple by drilling down through the sleeper, underlay and board and dropping the wire right through and then soldering the upper end to the sleeper!

Another good point is that buildings around the yard can be placed in a prepared 'hole' in the foam, each having a 6mm blank 'skirt' around the bottom for this purpose. Once in place there is no embarrassing gap showing around the bottom of any buildings, which occasionally occurs with time when they are glued directly onto the table top. (have a look at photos of various layouts to see what I mean!)

Hope this 'diatribe' has been of some use.

Bengunn

[Peter]

Hi David,

I last used the Hornby Type Sponge underlay about 25 years ago for a layout my son had. I was never impressed. It did not look like ballast and and we had trouble particually at points in keeping track level. It is not cheap and eventually the sponge breaks up and disintegrates.

Consider Woodlands Scenics Track bed, available in rolls, sheets and strips. It will also deaden sound, but it does not become brittle and is cheaper then the foam type underlay. Can be used in exactly the same way as Begunn describes. I have used it extensively over the last couple of years although of course adding stone ballast dose remove some of the sound deadening qualities.

Hope this helps.

Peter

[lukee]

Sponge does sound a bit rubbish. Think I'll use scatter ballast. :)

[kevin141]

have always used cork for a underlay bit fiddley sometimes but works well if time taken

[Flashbang]

Hi
Sponge underlay will deaden sound but it really just doesnt look like real ballast
If you use foam/sponge ballast then where surface mounted motors are fitted turn a small strip upside down and place under the motor, trim with a craft knife or scissors to match the size of the motor.

If you want to represent ballast IMO the best method is to use real stone as sold for the purpose. I haven't found it necessary to lay the track on foam or cork. Preferring to lay the track directly onto the baseboard surface. Then apply real stone ballast in the finest grade, and bond all in place with a 50/50 mix of PVA and water with a tiny drop of washing up liquid added. Allow at least 24 hours for everything to dry then hoover off any surplus unstuck ballast and touch in with a tiny drop more ballast and glue mix any bald areas to make good etc.

Only down side of this method is that the track cant easily be lifted and reused!

Looks like this when finished
http://i190.photobucket.com/albums/z311/Flash_bang/P1000.jpg

[TWICK9]

Lovely Photo of yours Flashbang.

[Simon]

here is a good demo of how to ballast a layout

YouTube- How to Make a Model Railway: Part 1- Ballasting

its the way im going to do it. and also, that layout looks very nice. hopeing to make mine to that sort of standard

[Flashbang]

Nah....
Far to messy and fiddly!
See my answer to this in a previous topic. http://www.modelrailwayforum.co.uk/showthread.php?t=405
I can dry ballast and then glue about 1 mtr or so in around 1/2hour. No real mess and certainly nothing to wipe off of the tops sleepers etc.

Good luck if your going down this line,but I think you will return to the "usual" method though!