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how do I build a tunnel

18K views 27 replies 11 participants last post by  beavis 
#1 ·
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
 
#2 ·
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.
 
#6 ·
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).
 
#8 ·
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
 
#9 ·
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:)
 
#10 ·
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
 
#13 ·
I did that too with one of my boys school projects when he was young.
I think I used a bit too much glue.:rolleyes:

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

By the way welcome Dizzy:)D) gurl to the site.
 
#22 ·
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! :D

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 :)
 
#25 ·
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.
 
#26 ·
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?:D

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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