…admit it: you're impressed.
by Jeff Faust, Genesee-N-Ontario Model N-Gineers
One of the many joys of T-Trak is that because modules are small, they lend themselves to experimentation. Lamination bending is an advanced woodworking technique that I had always wanted to try. What better opportunity than a T-Trak corner module—or a set of them?
For the Crescent Curve modules, I made a single-sided plywood form curved to the radius of the inside face (14-3/8" outside radius, minus 3/8" part thickness) of the laminated part. The form (see photo) included clamp blocks attached with carriage bolts and hex nuts. The convex surface of the form was covered with a couple layers of clear shipping tape to prevent the lamination from adhering.
Note that I didn't account for "springback"—the tendency of the part to try to straighten itself out after leaving the form. The laminated parts for Crescent Curve are about 1/4" greater radius than they're supposed to be (since the parts was to be trimmed afterward anyway, and other module parts milled to fit, this did not pose a problem in construction, and is not apparent in the finished module). If your lamination project is similar, make your form about 1/4" smaller in radius, and your finished part should be pretty close.
For each laminated part, I resawed 4 pieces of red oak to 3/32" thick, 2-3/8" wide x 24" long (oversized, for trimming to final dimensions after lamination). The outer plies for the four corner modules were all cut from the same piece of lumber, and marked for orientation, for consistent grain across modules when two are used together in a layout. Resawing is a tricky business, but I have access to industrial-quality machinery for the job, including a wide-belt sander to perform the final thicknessing. However you do it, work carefully!
Before the glue-up, it's a good idea to do a dry run first. Stack the plies (with a layer of thin hardboard or MDF on top to distribute the clamping pressure), lay them on the form, and attach the blocks, working from one end of the form to the other. I used a speed wrench with a 7/16" deep socket to quickly tighten down each block. Are the plies clamped nicely together without any visible gaps? Did everything get clamped in less time than the glue's listed "open time?" Good.
I used Gorilla Glue for lamination. This stuff, in my opinion, is overrated for most woodworking applications (I usually use white or yellow glue), but it does have properties that lend itself well for bent-lamination work. An old gift card makes a good glue spreader. I had my trigger bottle with plain water handy, and a disposable glove on to keep the glue off. A thin, even layer of glue was spread across the entirety of one face, the opposite face was dampened with the trigger bottle, stacked, and repeated. The whole sandwich went into the form, and the blocks were snugged down. I gave it overnight to set.
After removing the laminated part from the form, I flattened one edge on the jointer, then carefully (very carefully) cut the part to final width on the table saw. The module's footprint was laid out on a scrap piece of plywood, the part aligned to it, and marks made for trimming the ends to length. Both ends, and the upper edge, were rabbeted to accept adjoining parts. The other parts for the module were milled up, and everything was assembled, sanded, and finished. Track, scenery, feeders, and adjustable feet completed the module.
If you're considering lamination bending for a future module, check out these two books first to learn details of the process:
Wood Bender's Handbook, Zachary Taylor (Sterling, 2001)
The Complete Manual of Wood Bending, Lon Schleining (Linden, 2002)
Take a look at this time-lapse video of the process, too.
Is this a lot of work for a module? Of course. I like the look of wood, however, and solid oak has proven to hold up well in the rough-and-tumble world of exhibition railroading. If you want curved fascias with less effort, consider the other techniques described in the books above, or use wood products, such as bending ply or kerf-core MDF, specifically made for curved work. These may be veneered, or simply painted after fabrication. (As I have no plans to build additional corner modules, I will consider offers for my bending form; shipping not included.)
Good luck with your module!