Not a lot of visible progress again this week. I missed the Saturday meeting as I had to take the wife to her heart doctor for test results. She passed them all and can wait another year and a half to return.
The recent pictures showed a lot of cardboard strips and profile boards. I again started with Elmers yellow carpenters wood glue as that is what I am familiar with. It grips quickly and sets up in just minutes.
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But, I found that hot glue is even quicker, just look out or you get burned fingers. The profile boards were trimmed to fit using a single edge blade or utility knife. I like to support the boards from below and at least one edge or from 2 edges. Glue will run down the corrugations so build it up along the paper edges. Hot glue will build up better if you give it a good squeeze. And NOTE: hot glue doesn't work well on foam, it just melts the foam. I made a lattes of strips as you see on the right and just connected the profiles on the left. The cardboard frame gets quite stiff after the intersections are glued. Of course this is all to support the plaster cloth that should be coming in the next week.
The outside profile boards were started with white paper sided foam core board as seen on the right above. I spread glue along the bottom edge and lined it up with the outside edge of the frame. When my cheap supply ran out I switch to cardboard boxes, but found I had to add strips on the outside surfaces to hold in position. These strips can be plainly seen on the brown left side boards. After the internal structure of profile boards and strips are glued in place I am able to remove the strips. To ensure the outside boards remain vertical and inline with the frame I check it with a vertical surface from time to time.
The final fascia will be 1/8" or 1/4" tempered hardboard which will start at the lower edge of the frame board and be trimmed to the top edge of the outer profile boards. I plan to attach it with glue and screws, maybe set in finishing washers.
I have to paint and ballast the track just inside the tunnel and maybe a few other places that will not be accessible after the plaster cloth is applied. I will also have to form the inside walls and roof of the tunnel for several inches inside the tunnel that will be visible. I will also have to cover all the track in the area to protect it from plaster and paint during scenery work.
My homework for the near future will be creating two tunnel portals, a plate girder bridge for the mine track entrance, and 3 inside and outside trusses for the curved 3 section bridge. Here are some prototypes.
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| This sample was made from foam board, same as foam core, but without the paper surfaces. I simply used a dull point to scribe the stone outlines and stained the whole thing with light brown or dark tan, take your pick. |
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| This truss is built of 3/64" square bass wood with card gussets. The real ones will have gussets on both sides and support the cross beams between trusses. The joint between the center section that meets each end section will be supported by an extended beam reaching out to clear the lower track, one to the inside and one to the outside. You will see later. |
The girders will probably be made of card with a rolled strip for the top. Not on paper yet, still in my head.
Our next meeting is Tuesday 7-10-2012 and I hope to have a lot more pictures to show. I lost my camera so these will be taken with my phone.
Till then,
Armchair
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