I have been building craftsman kits for a long time and I have observed that today’s laser cut kits are substantially better engineered and usually product a model that won’t warp or fall apart.
I have an old Campbell Silver City mine kit that I opened up to study the instructions last night. It is basically cardboard that is cut out and glued together and then covered with corrugated sheets. My question is what special techniques do you use to keep this from warping and falling apart. Do you paint the insides before assembly? How much extra framing of the insides do you do?
This kit looks like it will be a challenge.- Nevin
Two options you have here. One, using the original kit cardboard, cut the pieces out and seal them with a clear lacquer, most of us have Dullcoat in the spray can around. Do this after cutting the pieces to size so that you seal the edges of the cardboard, making it less likely to warp.
The second option is to use the kit cardboard pieces as patterns to cut new pieces out of foam core board or even sheet styrene.
For bracing, as a general rule, all parts get a “frame” made of 1/8 inch square styrene. Make sure one wall has the frame set back to allow the walls to be assembled properly. Any part longer than about 4 inches gets intermediate bracing.
If you’re planning on interior lighting, then any type should be painted on the inside.
I don’t know what “foam board” is. I do agree with Tom on sealing the card stock if you use it. How about using sheet and 1/8 square wood for his second option? Maybe that is what the foam board i
Implied but not said, paint all sides of the cardboard including edges and at the same time with the same paint. The same must be done with all the wood parts. I like strip wood over the styrene because that is what I learned 60 years ago. I have built all my Campbell kits as delivered and I like them a lot. I think foam board is that paper product that is about 1/8 inch think and has 2 sheets of paper attached to a sheet of foam in the middle. It comes in many colors. It works like tag board, but does not bend as easily. Archetects use it all the time for their models.
wallyworld (walmart) has foam board in several colors and thicknesses for a few bucks a sheet. i think it is in the section with the school supplies. check it out. i picked up a bunch of it and use it for building mock-ups just to see how things will fit on my layout. then i can use the pieces i have cut for a base wall when i start on the finished structures.
I have braced the heck out of all of my craftsman structures for years now and quite honerstly, have never had one show any signs of warping. I think far too many hobbyists throw in a couple of thin square wood strips at the corners of a structure and consider that good enough bracing. I’ll tell you right now, it usually isn’t enough, especially if the wall section is of any real size. Not only do the edges need support, so does the field. Sealing all sides of a wall with paint certainly does help but without additional bracing, I’ve seen even these show signs of distortion over time.
I would add that if your layout is located in a spot subject to really large swings in temperature and humidity, cardstock simply is not a good choice, regardless of how much effort you expend sealling it. Styrene is a much better substitute in that case (I’ve never been a big fan of foam core, by the way).
Thanks to everyone for their suggestions. I think I will use the cardboard as a template and build the structures from sheet styrene. I think it will make a nicer model. - Nevin
I have some old paper sided freight cars that still look quite straight and even after 6 + decades of service. I did not assemble these cars so I do not know if the interior surface is shellac’d or braced. I have also seen plenty of old Campbell and Suydam structures on layouts that still look fine. So it is possible to use the older materials with success.
The problem with most foam core is that the outside surfaces are paper, which means all the warping and humidity issues are still there, but some types have plastic for the outside surfaces which would resist warping better. But any kind of foam and foam core product needs its own bracing too.
