I'm cutting out the "die-cut" windows from the 4 walls of the HO-scale (1:87) Campbell Boat House kit and most if it has gone fairly easily, but I've had much greater difficulty cutting the window and door openings in the two end walls -- and there was a major difference in the manufacturing method I used to create them.
For scale, the walls of this building model are constructed from 1/32" Basswood that's scribed by the manufacturer to represent individual boards. To get the entire wall height, it's necessary to butt-joint two or three pieces lengthwise into a single wall. Knowing from experience that such butt-joints, even in 3/4" lumber are notoriously weak, I decided to laminate the manufacturer's supplied, decorated walls with very thin (1/64") aircraft plywood that I could cut into a single piece the size of the entire wall.
For the two side walls I butt-jointed the wall segments with yellow glue and then used a spray contact cement to laminate the plywood backing.
For the two end walls -- the first ones I made -- after using yellow glue to butt joint the segments, I laminated the plywood by "painting" the walls with additional yellow glue.
Apparently the yellow glue in the lamination process soaked into and between the wood fibers of the plywood during lamination and greatly strengthen them to shear deformations (i.e. cutting).
Fascinating. And possibly a way to strengthen other plywood as well. Although, to be fair, the lamination layers in this plywood are incredibly much thinner than those in conventional plywood. For example, 1/4" plywood with as many as 7 layers -- a very high quality raw material -- has laminates that are 1/28" thick --- the thickness of conventional veneers.
But this plywood, 1/64" total thickness, is (IIRC) 3 ply, making the three layers each roughly 1/200" (roughly .005") thick. I have difficulty imagining any strength at all of a wood "slice" that thin so I guess that filling in the matrix with glue would result in a significant increase in strength.
Norm