Tunnel time

[keitaro]

all right it's tunnel time.

 

Ok so I am building a tunnel that curves up and comes out at the top side of the mountain then onto a bridge that crosses a river then into a mountain on over side of river and curves back down to ground level.

 

and suggestions on best way to make this.

 

I was going to grab a few big blocks of foam and make an L shape then carve out the track curve and mould the mountain shape.

Using paper masche and then put some plaster/spackle over this to hold together and give it a proper mountain shape.

 

does this sound do able or is there a better way to be doing it.

[KenS]

Getting a smooth grade on carved foam can be hard to do. I'd use a WS incline for the grade, and build up the mountain around it.

 

Whatever you do, don't forget to leave yourself access into the tunnel to fix derailments and clean track.

[keitaro]

I was thinking have a side cut out of the foam that holds in place with a small stick glued to the side that I can pop off to gain acess.

 

I was hoping to have the mountain permanent so I think the side at the back is best option. I now have an abundance of foam to experiment with haha.

 

So applying plaster onto of the foam and paper to smooth over the mountain to give a natural shape is a bad idea?

 

 

I was going to hollow through the foam and use a self made slope from some 10mm mdf I have which is quite flexible but firm enough to not be flexed by trains passing the track to create the grade through the mountain.

[Bernard]

Here is a thread on the 2009 Project Party. My project was to construct a diorama of a tunnel. Here is the link of the process I did to make the tunnel, it might give you some ideas:

http://www.jnsforum.com/index.php/topic,1680.0.html

[KenS]

So applying plaster onto of the foam and paper to smooth over the mountain to give a natural shape is a bad idea?

 

There are a number of ways to use foam.  I think carving it to rough shape (with a knife, and ideally using a rasp like the Stanley Surform Shaver), and then coating that with plaster cloth to provide a more paintable/glueable surface is the best approach.  But it's not the only one.

 

I don't think using paper/plaster above uncarved foam is a bad idea.  If I understand what you're suggesting, it's a mix of the old "cardboard ribs, masking tape and paper under plaster cloth" approach, just using the foam to provide part of the structure.  In some ways this is easier than carving (no need for a filter mask and vacuuming up all the foam dust), although I've always found applying plaster cloth to wadded paper to be hard (but maybe that's just me).

 

There isn't really a "right" way to build scenery, as long as it's sturdy enough to stand up to use, and provides a surface you can apply scenic glue and paint onto.

[keitaro]

KenS i was thinking to do paper mache then i was going to mix plaster like spackle or modeling plaster and smooth that over the foam and paper to give the rock/mountain like hold and shape then paint and add detail to the mountain

[KenS]

That works too, although the results will be fairly heavy.

[Bernard]

How about Sculpt-a-Mold?

http://www.allartsupplies.com/item.php?articleId=567&gclid=CO6b_5Kh3aYCFQQ65QodWRlF2Q

 

I use it as a finishing element for landscapes. It adds texture to the scenery and is light weight. I is a form of paper mache and is easy to work with. You can even add color (green or earth tones)  to it as you mix the scupt-a-mold with water.

 

In making mountains or tunnels, as Ken has said, there is no right or wrong way....just find the way that you prefer working with.

When you were mentioning working with plaster like spackle, have you considered "hydrocal cloth"?

http://www.modeltrainstuff.com/Woodland-Scenics-C1203-Plaster-Cloth-p/woo-c1203.htm

After you finish carving the mountain, cover it with the cloth and after it sets use the sculpt-a-mold for texture, stain/paint the mountain (either green or earth tones) then add the ground cover.

[Kamiyacho]

have you considered "hydrocal cloth"?

 

That is the system I use as well: foam, plaster cloth, sculpt-a-mold, paint/stain, ground cover.  Spackle seems much more at risk for cracking.

[cteno4]

curts foam mountain has held up well on the jrm layout after a year of it getting carted and banged around.

 

if you do plaster cloth or paper mache over uncarved foam then i would make sure you have a sturdy understructure where the foam is not. folks have had sagging when they used wadded newspaper and the plaster cloth sagged some over time.

 

shaping the foam can be messy, but you can then create a great strong shape. then cover with plaster cloth or you could just pin down cheese cloth to the foam and coat with a thin layer of plaster to just cover the cheese cloth. this makes a great hard shell to work from. then you can add plaster rocks (if you want rock faces) or sculptimold as bernard suggested for more organic texture, then paint and ground over.

 

sculptimold is really light weight and resists cracking as it flexs a bit. its basically paper fiber mixed with a water soluble binder. not as hard as plaster, but pretty tough and very light weight. not sure how well it would bind directly to foam, never tried that, have you bernard? perhaps leaving some pin heads in the foam sticking out a few mm would be enough to anchor it well. you can also mix some cheap acrylic paint into it as you mix it and give it a base brown color so if it ever chips you dont see a white/gray area all of a sudden (you can do this with your plaster as well).

 

so it sounds like you were successful in finding foam! where did you find it?

 

cheers

 

jeff

[omar]

dry wall joint compond also works. not as heavy as plaster. If you are going to use a lot of plaster go to the big box store and find the 25 pound bag. It is not that much more than the little box.

[scott]

I'd use a WS incline for the grade, and build up the mountain around it.

 

^^^^^^^^^^^^

 

If I could only buy one pre-made product, it would be those inclines. Lots of insanity saved there.

 

Spackle seems much more at risk for cracking.

 

Oh, I learned *that* the hard way. :-P

[keitaro]

I used plater of parris. So far so good no cracks lol. Did about 5mm thick