Thank you, Mr B - those two methods also looks very doable - I will have quite a few options for my next building!
For this one, I just mentally flipped a coin and went with black thin cardboard (the kind one use for posters), cut some overlapping strips, and secured the cardboard to the inside of the building with CA, before cutting out a hole in the cardboard for open doors and windows.
I'll do a light test tomorrow (when I can find a small light ...) and see how it works.
Smile, Stein
This Atlas roundhouse has very thin walls, so I printed up a cinderblock pattern on cardstock (thick paper, the thickness of greeting cards) using my computer printer. I cut the pieces to shape, including window holes, and glued them inside the building. This both provides light-block and gives a good appearance to the inside of the building. Although measuring would be a bit tricky, you could still do this from the underside of the building. Even if you cut away most of the base, the rest would still be solid enough to hold everything together.
But, I couldn't help noticing that your building has only a couple of small open doors, and no windows on the visible sides. If you cut out the base near the doors, you could build an interior wall module, complete with floor, walls and interior detail, that would be visible through the doors. Only the interior module would be illuminated, so the light would not leak through the rest of the building.
Another option is to take a sharp knife and run it under the roofline. Your roof may seem to be solidly attached, but I'd guess that a bit of cutting would pop it off again pretty easily.
It takes an iron man to play with a toy iron horse.
Ah - either one of those should work. Thanks you both for the ideas! I guess it is back to the work table for me to see what I can do with construction paper, foil or even thin styrene plates.
Stein
You could try cutting colored construction paper to fit the interior. An advantage of that is the interior of buildings are seldom black or silver. A common color would be light green in an industrial building.
BTW I paint building walls with gray primer on both sides before assembling, then paint the outside and often as not leave the inside gray. That way it gives a contrast if you look in the window. I like to do at least minimal interiors in my buildings if possible.
Howdy, Stein,
Two words - Aluminum Foil.
Not only will it light-seal the walls and roof, but it will reflect that light back into the building and intensify the interior illumination. The only problem area will be anchoring it to the walls at doors and windows without having it visible from the outside. Most of it won't even need to be attached.
Chuck (modeling Central Japan in September, 1964)
I got a little too eager assembling a 30 x 160 scale foot H0 scale warehouse that I made for my layout from two Pikestuff warehouse kits, with foundations and a loading dock made from styrene sheets:
I did remember to paint the interior floors concrete grey - so looking in through an open loading dock door you would see what appears to be a concrete floor. But I just plain forgot to spray paint the inside of the walls black and the underside of the roof panels white or silver before assembling the building.
After realizing my mistake I have cut a couple of access holes in the floor from inside the foundation so I can get my hand into the inside of the building from inside.
But I am sceptical about just trying to spray paint the inside of the building through the access holes - I fear it would probably create an unholy mess if/when paint escape through small cracks in joints, by doors etc.
Any recommendations on what would be a good way of light proofing the walls and roof going in through these access holes, without creating too much mess ?