Hydraulic Heaven

I am still struggling with slopes on Freshwater, which looks like it should be flat. However, the platform leads into the station building then to the road without steps, the road leads into the goods yard at track level by the front siding, at cart loading height to the shed door, which is at platform height on the other side. However, it was possible to drive from the goods yard area on to the platform of the station concourse.

 

 

I have used air drying clay on wire tree armatures, and it dried overnight, but that was a very thin coating. I would worry about cracking if drying too quickly, and if the layout baseboard 'flexes'. Some more flexible filler might be a better solution. Polyfilla with lots of PVA glue mixed in, maybe?

 

 

Hi Ian,

 

Glad to hear that it's not just me that struggles with this. Your diagram is clearly the answer - just build that

 

Seriously, I think it is tricky - I think we are conditioned to dismiss things as 'flat' but we need to change our perception. I found that cycling on roads that I'd previously considered 'level' when out driving changed my perception of them pretty quickly. The trouble is that even when we know that there are subtle variations in level, it's still difficult to work them out by looking at photos. Going to the real place can help... but only if the ground levels haven't changed (which in the case of Hayle they have... a lot).

 

Mucking about with bits of cerial box and clay certainly helped me to get to a conclusion that I was happy with.

 

I was wondering while doing this whether clay would be usable as a ground making material for real. I've now decided that the answer is 'no'. My clay is dry in places now but the main issue is shrinkage - the paper templates were wrinkled where they had been pulled around by the shrinking clay. A quick slice with a sharp knife around the edges of the clay to separate it from the paper has allowed me to straighten the paper out again. I will stick to the more usual things like Sculptamold for the real layout.

 

Regards, Andy

One thing that can cause problems is where a layout has been compressed to fit into a smaller space it will effectlively increase all the slopes. What looks flat to someone on the ground may well look quite different iff supressed and seen from a different angle.  From Memory the road from Freshwater High Street slopes down to the former station site. The Co-op supermarket has obviously changed levels in that area.  I could well believe that the platform being 2 to 3 ft above the rail level could gently slope down to rail level along the road to the goods yard.

 

I find corrugated cardboard of various thickness very useful pushing down of the cardboard you can create dips  a coat of dilute PVA will then toughen up the surface and allow scenic materials to be stuck onto the surface ( sifted dirt or very fine sand are possibles for the base layer)  a thin wash of pollyfilla can also prefpare the surface.  For thicker landscaping I would use papermache ( use domestic shredder to chop up the paper) or going thicker cardboard profiles with interwoven strips  of thin card covered with torn strips of newspaper stuck on with diluted pva.

 

Don 

Cheers Don. I've always chucked any corrugated cardboard in the bin having never found a use for it but maybe I'll give that a try. Just put a load of it out for the recycling binman tonight as it happens. I'm sure more will be along quite soon though.

 

Regards, Andy

It is quite useful stuff. You can create mounds by cutting out contours and layering using pva to fix and coat exposed surfaces before applying polyfilla to produce a smooth surface.  I also makes useful profiles for the woven card strips. I use a hot glue gun to fix in place.  

We also use large quantities to add to the compost bins it helps to balance out the grass cuttings from the mower. 

The paper mache I mix up wallpaper paste I teaspoonful to 1/4 of a pint then added shredded paper until then pasts has ben absorbed so it will not drip.

I find these material much less messy than the expanded polystyrene which seems to get everywhere.

 

Don

Thanks for the info Don. I've used the more dense builder's rigid insulation foam on South Yard and St Ruth for making big volumes of 'hill'. I'm not sure exactly what the technical term for this material is. The stuff I've seen more recently has foil on both sides so I have been wondering what I will use for the new layout - maybe the non foiled stuff is still around and maybe it isn't. I haven't really looked very hard yet. It wont be expanded polystyrene though - I agree it's 'orrible stuff when you start cutting it.

 

The ground at the rear of the quay will need something fairly substantial though. It's neither low nor subtle.

 

Regards, Andy

The stuff with tin foil both sides is generally Celotex which is extruded Polyisocyanurate insulation, which when cut gives a fine hard dust, definately wear a mask when cutting it.

Don't take the tin foil off just one side, it turns into a banana, if you take the tin foil off both sides , it's a lot less ridged so when using it for a base board  I keep the tin foil on (use non solvent "glues like nails" type adhesive)

 

Extruded Polystryrene  is available in pink or blue or yellow (manufacturers colours), no tin foil, various thicknesses, used for under floor insulation, is the best for baseboard, again you need a dust mask to cut it.

jewsons, insulation express  and SIg,  Sell it.  You may need to buy 4 or more 4 ft by 2ft sheets at  a time or more.  (You can get BIG sheets)

 

Expanded polystyrene, white, sometime grey,  forms bubbles when cut, they get everywhere, but it is the most commonly available, and usefull for non structural hills..

Edited July 4, 2019 by TheQ

Thanks for the info - will save me a good deal of googling time. The pink extruded stuff sounds like what we used last time around. I definitely want to start with something where I dont need to remove foil or whatever other facing if possible. The baseboard structure will be the more traditional plywood.

 

Regards, Andy

I tried that white polystyrene some years ago on one of my old layouts but found that it wasn't easy to sculpt to the long shallow and gradual contours I needed. Even with a hot wire cutting device. I also heard that over time it degrades wiring but I don't know how true that is. 

 

The dense 'Cellotex' The Q detailed is great stuff. I've used it loads of time and fixed it down with lashings of PVA. It cuts smoothly with Stanley knife blades and using the 50mm ish sheets you can cut both sides with little mess to get thin sections. 

 

There is also some really dense insulation called 'Floormate'. Available in various thicknesses, light weight,  it carves quite well. Usually light blue in colour. Takes PVA well. 

 

For the covering finishing material, having experimented with Polyfiller, bonding plaster and various other products, I have settled on pre mixed tile adhesive, it dries quite quickly and goes of like rock.. I usually add a water based or acrylic light earth paint to it prior to plastering it on the Cellotex and forming the desired land scape. That way if there is any shrinkage or cracking the colour remains consistent and it is not so obvious. It also carves well.

 

I used the Cellotex and tile adhesive method on the chalk quarry. Obviously less precolouring required on the chalk.

 

 

 

 

 

 

 

Thanks - looks good. I'm assuming your Cellotex had foil on it?

 

Having said that I'd prefer foil free stuff I'm also thinking that anything polystyrene based will do bad things in a fire. None of us want a fire but it would be nice to know that I'm not creating hills stuffed with flammable material that will create poisonous fumes if the worst happens.

 

Regards, Andy

If you have plastered your layout with polyfilla as a surface, and  your layout has caught fire. Then  you have a lot more to worry about than the layout, your house has already burnt down.. Celotex IIRC is 300C to catch fire.

 

 Most sheet polystyrenes now contain a fire retardent, it still will melt and fume but needs a much greater heat to catch fire.

 

Pollyfilla is for the most part the same as plasterboard used for it's fire resistance.

 

The plastic coating of wiring does degrade in contact with polystyrene, however at 12V  thats not going to be a problem although if you remove the wire on rebuild it will be a bit sticky.  I've experienced this myself unpacking equipment that spent 10 years in a air temperature (50C+) hanger in Saudi, the polystyrene bubbles had melted and fused to the mains cables. A sticky mess that took ages to clean up..

Fire retardant will be fine. I dont want to go over the top but I also dont want to inadvertently create a fire hazard.

 

Looking at some of the stuff on the Interweb, the Cellotex and similar products have a good deal to say about fire resistance. The only specific thing I've found on fire behavior of the extruded polystyrene stuff says that it needs to be enclosed (something along those lines).

 

No doubt there is better info out there and I'm still a good way off actually needing to make any hills - this was just a quick trawl.

Grenfell tower was insulated with something like celotex,  but they put it on with an air gap creating a 220ft chimney fed by the gas fire escaping from a flat near the bottom. Under those circumstances almost anything will burn. 

 

In the circumstances of a model railway with polystyrene sandwiched between it's baseboard and polyfilla.  You'd have to stand there with a blowtorch to get the model built with polystyrene  to catch fire. There are a great many higher risks in your home.. 

There are two things to consider in fire resistance one is the breakdown of material due to heat  obviously the worse condition is material which will spontaneously burst into flames at high temperatures the other is whether the material will catch fire in contact with a flame.  In the context of a model railway layout flames will set alight the wood and ply of the baseboards which tends to be the bulk of a layout. I wouldn't expect the use of insulation materials to be a great risk. Obviously a serious house fire would be likely to damage the layout. The main risk of a fire caused by the railway activities are from either contact with a soldering iron or a naked flame ( may seem odd but I have seen suggestions of using a candle to create soot effects on bridges and tunnels ) or an overheated solenoid or motor.

For domestic appliances the usual practice is to either ensure the current is at a level which will not cause overheating or provide a fusible link ( a piece of solder in the supply to the coil placed against the coil which will melt at a safe level for the coil insulation.  I have been involved in both methods in a professional capacity designing domestic appliances. In model terms the solenoid type of point motors are intended for intermittent use. If using a probe and stud  there will be little risk of leaving one connected but the passing contact switches could possibly maintain contact usually there will be  abuzzing sound if the coil is left on.  Locos are not noramally left running although it is possible to have a loco powered and held against the buffers unoticed.

The simplest answer is to have all the power supplied to the layout supplied through a single switch point, the same applies to the workbench so that on leaving the hobby room (or corner of a room) throwing one or at the most two switches will remove all the power.  Having  lights in the circuit will act as a reminder.  It is wise to do this even if leaving the room for a drink or a meal.

In practice the layout is probably more at risk from other parts of the house. A little sensible care will make life safer.

 

Don 

 

Thanks both for the advice. I will definitely avoid candles.