Associate editor Eric White describes how he made his own molds out of styrene to make plaster castings. He used this technique to create the tunnel portal and liner on the Model Railroader staff’s HO scale Eagle Mountain project model train layout.
Casting a tunnel liner and portal for the Eagle Mountain RR
By Angela Cotey | August 19, 2016
| Last updated on November 23, 2020
Learn how the Model Railroader staff created this scene on the HO scale Eagle Mountain RR project layout
Very cool Eric… although your first mold attempt had a few air bubbles, I didn’t see any that would be a ‘show-stopper’ by the time you painted it and none would be visible to any visitor. It is helpful to mix/pour a little more ‘soupy’ the next time, plus your idea of a drill to help remove air bubbles is a great idea. On the opposite side between two buildings, couldn’t something else be added to help hide the cutout in the backdrop? I like the operational capabilities of this layout.
Hi Randy,
You scared me for a minute, but I mention the sleeve for the form in the last paragraph of Step 2 on page 23.
You can see it in place in the photo for Step 3.
Thanks for reading and watching!
Ah Ha! The article in MR Magazine left out the the part about the “outside box” for the mold. I was quite confused as we went from step C to step E almost effortlessly. Thanks for bridging that gap with this video. I have eleven of these to make in concrete. My wood ones I made 40 years ago! They’re done.
I don’t think you need to line the whole tunnel just at the portal where one can see inside .
How do you retrieve a car/s if there is a derailment inside the tunnel?
I fix a jigsaw without the blade to the underside of a flat surface. Any castings are made on top of the surface. The vibrations work out any air bubbles. If doing a lot of castings it is easier than holding a drill.
Have a couple tunnels that need the same inner parts, so this is a timely project for me.
A few years ago I used a jig saw without the blade to vibrate a mold for casting resins
What material did you use for the mold?
Nice bit of scale engineering to solve that problem. I like the idea of using the drill to vibrate out the bubbles in the plaster pour.
Using the drill vibrate out the bubbles is really clever. I like the look of a more modern tunnel liner, too.
very interesting. I need a couple liners, except that I was impatient to be ready for an open house and put the portals in place already. Could be a bit of a challenge 🙂
that’s cool ill have to try that