Glen Finnan Viaduct

Yes, thats pretty much plan B at the moment. Ideally rather than use the stone paper that Faller make I was hoping to find something like the plaster stonework that Town street make. There stuff is great but for the projected size I am thinking of this would cost too much. I was thinking that a large plastic kit may be a cheaper option if available.

Another idea I had, which is more inkeeping with the original, is to make it from wood and cover it with plaster if paris then shape and paint that. The real one is actually concrete and has just been made to look like stone. I'm not quite sure about bending the wood to the contours needed. I suppose if the woods thin enough it shouldn't be too much of a problem.

QUOTE (Dennis David @ 27 Jun 2006, 14:14) <{POST_SNAPBACK}>If it were my project I would use matboard.

Whats matboard?

It's the board use to create mats of course.

Bainbridge Matboard

I never really thought off that. Would plaster stick to it or would it become too soggy withe the damp plaster?

Thats not a bad idea. If I could make one mould then I could do all the arches from that and join them up.

thanks for that, that may well be the best idea.

Never made a curved bridge Neil, but I need to for the new layout I'm just starting. I had intended to make a shell out of flexi MDF and cover it with Slaters molded sheets. Another idea was to cover with stone sheets from International Models ( www.internationalmodels.net ) as I find their products amongst the best and you can get a flexible sheet from them ( molded polystyrene ) which is very good. Using this, only a framework would be needed. Anyway, the best of luck. Sounds like a project that would be interesting if posted to a new "builders corner" forum, if our esteemed moderators take notice of recent posts and start one!
Keep us posted on progress!

That sounds interesting I will have a look at that. I haven't seen those before.

Neil,

If you wanted to try to make the viaduct out of plaster cast sections, I am sure that it would be possible. I built my station in this way with my own cast plaster wall modules stuck onto a 3mm Birch Ply base, inside and out. You can see part of my model of York Station, Platform 1, in my avatar. The walls are plaster, as are the column bases and capitals.

I first bought instruction booklets and then materials from Alec Tiranti Ltd of Reading tel 0118 930 2775. They were very helpful and advised me what I would need.

If there is enough interest, I could post something on this site showing the masters, the moulds and the results. When you are modelling a series of curved arches like a station or a viaduct you have to get them all exactly the same, and the result can be very impressive.

See:
Alec Tiranti Ltd

Colombo

El cheapo Viaduct

Part 1 the frame work

I built a 19 arch viaduct on my last layout. My method was very primative but effective.
I ripped some 12mm super wood for the the track bed. I used fairly thin pine sections for the legs or vertical sections of the viaduct. I again used super wood for the base. I cut very small rebates in the top and bottom
sections to accept the verticals, which were then screwed and glued into postion.

Part 2 the covering

I had some Langley viaduct sections, these I painted and scanned. I bought some sandwich board from an art shop, this is cardborad with a polysyrene section in it. I then cut out the scanned artwork and glued it to the sandwich board using carpenter glue. When I had enough arches I then used a sculple and cut out my art work for the viaduct. The wood work was with sprayed grey primer. Once dry the artwork was glued to the wood work, and from the angle it was positioned I suprised to find that the lack of fill behind the arches wasn't noticable so I just left it as it was, and with very little cost or effort I had a viaduct of impressive proportions.

Neil,

The process to build a section of flat wall is as follows.

1.Take a photo of the wall square on, well lit.
2. Count the bricks and make a scale drawing and then a master, building in all the detail you like, curved arches, denticing, rebates, anything goes. I built my master out of 3 mm ply and covered it in plasticard, Ratio or Wills sheets and sections, arches, oriole windows, whatever. You have to think where the joints are going to be and where the repeat line falls. I decided to conceal my joints behind buttresses on the outside. For the inside panels, I added plasticard overlays.
3. I made a mould tray out of ply and lego bricks about 5 mm deeper than the master and about 8 mm larger all round. The bottom layer of Lego bricks has to be stuck down.
4. The master is stuck down to the bottom of the mould tray, right way up, taking care that there are no air spaces under it. I used double sided sticky tape.
5. Mix the latex and pour a little into the mould tray, lightly brushing the mix into the master so that all air bubbles are excluded from the detail. Fill up the mould tray to the required depth. You want a strong mould so do not skimp it.
6. Leave to set for four days.
7. Carefully dismantle the lego walls of the mould and release it from the master. Detach the master from the base of the tray. Rebuild the lego walls of the tray, invert the mould and place it in the tray where it will be a snug fit. Carefully trim away any flash with nail scissors.
8. Start casting the wall sections using special modelling plaster. Taranti's Alpha plaster is finely divided to pick up the detail and has high strength. You have to brush some plaster into the detail before filling the mould. I found that I could do two casts a day. I was casting an inside wall section, an outside and a buttress at the same time. I vibrated the bubbles out of the plaster on the top of my pillar drill casing, in which the belts rattle round, a perfect vibrating table. You have to keep the moulds flat in the trays or you get curved walls. I place thin strips of wood top and bottom and placed a weight over them. I use the heavy coils from defunct fluorescent lights. They are about 150 mm long and have a flat base; these are also good for holding down track whilst glueing.
9. A curved ply wall inner was built and then the wall sections were stuck to it using Contact adhesive. For a wall with windows make the wall inner out of perspex. The wall sections had first to be sanded to a constant thickness and the edges neatened to make a good fit. The buttresses were glued over the joins and the gaps were filled with white PVE glue from a hypodermic needle.

I have since built an engine shed using this method and I plan to build retaining walls for a long cutting based on Belper. This system is great for long repetitive walls. You can make your master as complicated as you like, you only have to do it once.

Colombo

Sounds good. I will check out the Langley website to see what their viaduct sections are like.

Colombo, about how much did this cost you? To make the mould that is? I seem to remember from looking at the website it was about 18 quid. I do like the look plaster has once it has been stained. This would probably be my preferred option if not too costly.