Weather proofing a Tunnel.

[NerdyDave]

Help - Assistance wanted by a complete Novice.

I am constructing a tunnel running through a mountain, ( approximately four feet long - Iv'e incorporated an "Escape Hatch in the rear, to assist with any derailments ) made from a combination of chicken wire, papier mache, and "Modroc" plaster bandage. As this will reside outside ( permanantly when it is finished ) and be exposed to the rigours of the British weather, I need advice on how to weather-proof it, either before I paint it to represent rock, grass, landscaping etc, or after all that is completed.

Any suggestions or ideas?

NerdyDave.

[dmaynard]

Being as that I am mostly a garden railroader I have a lot of structures outside. Weatherproofing is a challenge. Weatherproofing paper mache would be difficult. A good soaking in a good wood sealer might work. You would have to coat both the inside and outside of the mountain. Also put it on a base to prevent contact with the soil. Better choice would be to make the mountain out of a more weather proof material. Using screen covered with burlap strips soaked in a patching cement would be a better choice. Several folks on the Garden Railroading website I belong to have made mountains that way and they have held up for many years. I haven't made any that way so I cannot give specifics as to thickness of the cement/burlap layers and supports.

We had a plaster statue that my mom insisted she wanted outside, and even after sealing it well with Thompson's Water Seal it deteriorated rapidly. All it takes is one small pinhole in the coating and water will get in and cause it to soften and break down.

[NerdyDave]

Hi Dave.

Thanks for the input. Looks like my first attempt may have to be a short-term "temporary" structure.

Next time, I will heed your advice.

[ukracer]

I did the same with my layout in the roof it just soaked up the atmesphere, find another way.