# how do I build a tunnel



## ontario mainline

like the title said. seems like I saw somewhere,someone made one with foam insulation ? do you think that would work ? I have a sheet of 1/2 " foam insulation, that I could use. kinda like to make it look like a hill or something.
I have a roll of the woodland scenics plaster cloth,to cover the outside with.
so would the 1/2" insulation work ok ? also how high should the opening be,or should I get the portal first,and go from there. and yes it will be Ho scale,if that's any help.

Thanks 
Ron


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## Reckers

Ontario,

Good morning! Here's a tutorial, and I'm sure you'll get lots of additional information as the day goes on: http://www.thestorefinder.com/rr/rr_lib_landscape.html

Your tunnel has to provide clearance for: car/engine height + track height + roadbed height. If you have a curve inside the tunnel, keep in mind cars need more clearance than the trucks they ride on, and curves require more clearance than straight track. Also, give some thought to accessability: at some point, you'll want to work on the track, clean it, etc.


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## T-Man

Layered foam or carboard strips stapled and clothed, are the two main methods. Mostly it is sculpted foam.


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## ontario mainline

Reckers said:


> Ontario,
> 
> Good morning! Here's a tutorial, and I'm sure you'll get lots of additional information as the day goes on: http://www.thestorefinder.com/rr/rr_lib_landscape.html
> 
> Your tunnel has to provide clearance for: car/engine height + track height + roadbed height. If you have a curve inside the tunnel, keep in mind cars need more clearance than the trucks they ride on, and curves require more clearance than straight track. Also, give some thought to accessability: at some point, you'll want to work on the track, clean it, etc.


seen that before.but never bookmarked it. the tunnel will be in a straight area.no roadbed. ya as far as accessability,I would like to make it,so I could lift it off if I had to.

Thanks 
Ron


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## Reckers

No problem. If you're interested in building a hot knife, see this thread:

http://www.modeltrainforum.com/showthread.php?p=19930#post19930


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## Pton46

Building or even buying (I got one as a gift) great investment (hot Knife). Also get the Sheets of Foam from like home depot or lowes you would use on the exterior of your house. (I got my house done with siding and the crew gave me the leftovers). I framed a tunnel out of that and plaster sheets (Craft store).


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## bradimous1

Reckers said:


> Ontario,
> 
> Good morning! Here's a tutorial, and I'm sure you'll get lots of additional information as the day goes on: http://www.thestorefinder.com/rr/rr_lib_landscape.html
> 
> Your tunnel has to provide clearance for: car/engine height + track height + roadbed height. If you have a curve inside the tunnel, keep in mind cars need more clearance than the trucks they ride on, and curves require more clearance than straight track. Also, give some thought to accessability: at some point, you'll want to work on the track, clean it, etc.


out of curiousity... when looking at this link, I notice that this method leaves no way to get to the track when under the tunnel... is this an OK practice? I feel like the only things that can happen in this circumstance would be bad... thoughts please as I am starting my tunnel soon and this seems way easier than the way I was planning on doing this.


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## tjcruiser

Hi Ontario,

My kids LOVE our HO tunnel ... they sneak around the back (unfinished side) and peek through my little access windows to watch the trains go by.

I built ours out of 2" pink-stuff insulation foam. I rough-cut the individual pieces to size, first (some setback with each layer), then glued them with foam adhesive (from Home Depot) but also hot glue to achieve a quick grab. I carved with some fine-tooth hand saws and a sharp knife, and added a bit of rough "rock" texture by "whacking" it all over with a 50-grit sanding drum mounted on my drill. Then, paint to suit, and maybe add a little plantlife, etc.

I mentioned the backside access windows. In addition, our whole mountain/tunnel lifts off (upwards) for full access / portability.

I used some store-bought tunnel portals (foam, I think). I used my same 2" drum sander to carve an arch to the top-inside of the tunnel for the first several inches of tunnel depth, and painted it black for a semi-realistic look.

I screwed up a bit on the tunnel inside height, though. (My tunnel had a track ramp inside, so the inside height varied a bit.) I had previously measured the max height of my locos, and then mapped out the tunnel foam layout to that. All good, right? Well, when all was said and done, I hooked up several cars -- including a caboose -- and had our ceremonious first-run. Whack! Turns out, the stove smokestack on my caboose was my real high point. Dohh!

(I'm embarrased to say that I chop-shopped the caboose smokestack, rather than modified the tunnel height!)

Ohh ... word of advise when cutting the pink-stuff foam. It kinda gets everywhere, so do it in a blocked-off room where cleanup is easier.

Ohh ... one other tip (learned here, myself) ... If you paint your foam directly, you'll likely want to use latex (or acrylic) paint, only, as oil-based paint will disolve the foam surface.

Good luck!

TJ


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## Stillakid

TJ, now you've got me thinking I might be able to make a tunnel

I remember when I was a kid, one of our neighbors dad made him 2 tunnels at the same time. He used a big, long, thick balloon, and paper-mache. When it dried, he sawed it in half and had 2 tunnels. He actually made it look pretty cool


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## tjcruiser

Stillakid,

That's actually not a bad idea at all. I never thought of doing that. But ...

When my kids go to the dentist, they walk away with some balloon prizes ... those fat, long ones, like you're talking about. They have about 7 or 8 "humps" along the length ... kinda like rolling hills, now that we're thinking about that. I wonder how large (diameter) you could safely inflate one for paper mache layup?

Not a bad idea at all!

TJ


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## bradimous1

you remember those punching balloons... really big ones. I used those for a science project when I was a kid and put paper mache over it... to make a solar system. It worked great.


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## Dizneygurl99

Just recently started building a tunnel too and I found that cardboard strips as support with paper mache' over the top came out nice and rigid and only cost about $1 for the bag of flour lol

works especially well if you have an irregularly shaped tunnel.


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## Big Ed

bradimous1 said:


> you remember those punching balloons... really big ones. I used those for a science project when I was a kid and put paper mache over it... to make a solar system. It worked great.



I did that too with one of my boys school projects when he was young.
I think I used a bit too much glue.

You couldn't break it with a big hammer!:laugh:
We just used regular balloons of different sizes.

By the way welcome DizzyD) gurl to the site.


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## Dizneygurl99

big ed said:


> I did that too with one of my boys school projects when he was young.
> I think I used a bit too much glue.
> 
> You couldn't break it with a big hammer!:laugh:
> We just used regular balloons of different sizes.
> 
> By the way welcome DizzyD) gurl to the site.


Wow Ed! That must've been some strong stuff..and that was backed with balloons you said...had to be 50 layers...I hope the mountain in my new layout will be that tough haha!

You've probably just given me my official nickname..."Dizzy"...good stuff!


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## Big Ed

Dizneygurl99 said:


> Wow Ed! That must've been some strong stuff..and that was backed with balloons you said...had to be 50 layers...I hope the mountain in my new layout will be that tough haha!
> 
> You've probably just given me my official nickname..."Dizzy"...good stuff!


The way we made them was to cover the balloon then after it drys you pop the balloon.

I was only kidding.:laugh:
Just testing your temperament.

I used to have a girl friend who went by Dizzy. Just a friend. 
Last I time I saw her was at Woodstock, in the mud in 1969.


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## Dizneygurl99

big ed said:


> The way we made them was to cover the balloon then after it drys you pop the balloon.
> 
> I was only kidding.:laugh:
> Just testing your temperament.
> 
> I used to have a girl friend who went by Dizzy. Just a friend.
> Last I time I saw her was at Woodstock, in the mud in 1969.


:laugh: I can already tell you guys are going to be really fun...finally a forum with some wit! I bet you old men have some pretty awesome stories....my mom talks about the "Woodstock" days...she was such a hippy...

and duh i guess you would know more about paper mache seeing as how it's been around looong before me...


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## Big Ed

Dizneygurl99 said:


> :laugh: I can already tell you guys are going to be really fun...finally a forum with some wit! I bet you old men have some pretty awesome stories....my mom talks about the "Woodstock" days...she was such a hippy...
> 
> and duh i guess you would know more about paper mache seeing as how it's been around looong before me...


Was your Mom nicknamed dizzy?


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## Dizneygurl99

big ed said:


> Was your Mom nicknamed dizzy?


HAHAHA no....but that would've been pretty crazy....


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## Reckers

Diz, how long a tunnel are you contemplating, and on how large a layout?


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## Dizneygurl99

Reckers said:


> Diz, how long a tunnel are you contemplating, and on how large a layout?


Contemplating on my layout? Or Ron's? 

If you mean my layout, it's a long tunnel in the back of our mountain with a removable section for maintenance  and this would be on our layout that is 11' X 7' 1/2 "L" shaped table


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## Reckers

The reason I asked is that, for longer tunnels, sheet foam is a good material to work with.


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## Dizneygurl99

Reckers said:


> The reason I asked is that, for longer tunnels, sheet foam is a good material to work with.


I agree...when we started it that's how we wanted to try it, but didn't have access to this wonderful forum and it's great abundance of knowledge haha! 

SO when we couldn't find decent info on how to build it, I went with my gut and paper mache I'm hoping to start a progress thread of our layout soon


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## Reckers

Great! Please consider doing a tutorial on how to make p.m. tunnels. It's how we pass on info on this site.


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## Dizneygurl99

Reckers said:


> Great! Please consider doing a tutorial on how to make p.m. tunnels. It's how we pass on info on this site.


Yah no problem... Don't expect greatness, but I'll surely try a tutorial


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## cabledawg

We made ours out of oak. I know it's not the usual build materials, but we needed something strong that could tolerate being moved. Being in the military, we move alot and eventhough we move ourselves, everything has to able to take minimal space and survive 1000 miles ina moving truck.

SO ours is made of oak trim peices and oak board. Heavy and stout, but not very natural looking. We added some texture plaster stuff, but it still looks like a box. SO we might strip it and add a layer of expanding foam to the outside and then reshape it to look more natural.


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## Big Ed

cabledawg said:


> We made ours out of oak. I know it's not the usual build materials, but we needed something strong that could tolerate being moved. Being in the military, we move alot and eventhough we move ourselves, everything has to able to take minimal space and survive 1000 miles ina moving truck.
> 
> SO ours is made of oak trim peices and oak board. Heavy and stout, but not very natural looking. We added some texture plaster stuff, but it still looks like a box. SO we might strip it and add a layer of expanding foam to the outside and then reshape it to look more natural.


This is and older thread dawg.
She has not been here since Sept 9.

Instead of tearing it up maybe you can just add to it.
See the junk I used?

Newspaper balled up and pieces of foam.
Old bathroom ceiling tiles.
Mine is still a ways from being done.

http://www.modeltrainforum.com/showthread.php?t=5314


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## cabledawg

I guess it was a bit of a necro post, but I wanted to add to it since apperantly mine is quite different from the norm.

I have seen yours and a few others and really wished I had done something like that instead.


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## beavis

I've found this site to be very helpful for me as a first time builder, lots of info in these videos!

http://www.gatewaynmra.org/video/worlds-greatest-hobby.htm

I'm pretty much building my layout per these videos instructions with my own design and different track materials but the table and landscape will be built with these techniques.


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