Masonry tunnel portal out of cardboard

Discussion in 'Scratchin' & Bashin'' started by RailRon, Feb 19, 2006.

  1. RailRon

    RailRon Active Member

    I wanted to build a tunnel portal made out of cut masonry stones.

    Shaywen developped a fine technique for building such a portal out of pink foam. It's described in the Academy - see this link. But I don't like pink foam that much, so I tried Robin's favorite material: Cardboard! Then I applied some of Shaywen's coloring techniques to it.

    First I took a piece of stiff corrugated cardboard and cut out the opening for the trains.

    Then I added the tapered stones (called "voussairs") which form the contour of the opening. The shape of the center keystone with its cover stone is copied from a photograph of a PRR tunnel mouth.
    These 'stones' were cut individually out of stiff cardboard (shoe box). After glueing them around the rim I drew the lines for the masonry stone layers...

    Attached Files:

  2. RailRon

    RailRon Active Member

    Masonry structure

    Next I structured the surface of the cardboard face.

    At first I scribed the gaps between the stone layers with an awl. Then I added the vertical gaps between the individual stones with a screwdriver.

    Because I used corrugated cardboard, the lines didn't turn out perfectly straight and even - but this is exactly what I tried to achieve. After all, granite masonry stones aren't all alike - the wall face shouldn't present the uniformity of a brick wall.

    The next step was to paint the whole thing black, working the paint into every crack. I used acrylic paint for rustic arts, full strength out of the tube. I you don't thin the paint you shouldn't have problems with warping.

    Attached Files:

  3. RailRon

    RailRon Active Member

    Painting the portal

    With several hues of the same acrylic paint I colored the stones. The colors were dry-brushed onto the black surface, giving the desired effect of deep cracks between the masonry stones.

    Colors used:
    Medium gray and a light brown as a base color, mixing them by dipping the brush alternatively into splotches of the two colors on my palette.
    Oxide red applied sparingly to add a little bit of a rusty hue of brake dust clinging to the stones
    Black, mainly for the soot marks above the tracks
    White, also sparingly used, to higlight the upper edges of the stones.

    Next will be building a short piece of tunnel lining...

    Attached Files:

  4. ezdays

    ezdays Out AZ way

    Wow Ron, that's a really fine tutorial. Hand-laid stones, and they really look it. I would have guessed a molded part rather than cardboard. Great suff, thanks for sharing...:thumb: :thumb:
  5. jim currie

    jim currie Active Member

    neat Ron love to see a real scratcher at work :)
  6. zedob

    zedob Member

    Hey, cut it out, you'll put me out of business! Just kidding.:D Nice work.

    I've seen a few examples of using card board for stonework and am quite impressed how well it can look when painted correctly. Great work.:thumb: :thumb: :thumb:

    I guess that's one of the reasons I love this hobby, I have learned so many nifty techniques over the years from so many nifty people that have helped me on numerous non-railroad related projects in as many years. The Gauge has really incresed the input lately.:thumb:

    Hey, how about an ALL CARDBOARD CONTEST? Humm, the suggestion thread...:D

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