I am planning on building a version of Mike Danneman’s N scale Rio Grande that was featured in the March 1996 issue of Model Railroader. I am planning to build this layout so that I can move it in the future. In an attempt to make the layout a little bit lighter I am thinking of using 1x3 MDF material for the frame of the open grid benchwork. Has anyone used this type of material on a small layout with any success or should I use traditional 1x3 pine.
In my expieience from working with many types of wood, bechwork included, MDF would not be any lighter than using strips of 1x3 pine. plus, when butt jointed together at a corner the MDF is not very stong and has a tendency to break where the fasteners are used. The best material I have found for making the 30" x 60" modules of my semi-portable N scale layout is 3/4" birch cabinet plywood. If you have acsess to a table saw you can rip 1x3’s or whatever size you need from the sheets to use in place of dimensional lumber. While it is more expensive than pine, It is far more stable and resitant to warping than even the best solid pine you can find. This is especially critical because if you have multiple sections that come apart for mobility, you want the pieces to line back up when you re-assemble it! I build open boxes built of 4" wide boards with a 1/4" deep rabit cut in the top to accept flat 1x3 “bed slats” placed on 18" centers to support a top of 1/4" AC plywood. These modules have proven to be very strong and suprisingly light weight, even with plaster mountains built on them. The choice of table top mataerial is what affects the weight the most. Also, I recomend that the frame be made 4" wide so that a tortoise switch machine or equivalent will fit under the roadbed and have enough clearance so that you can set the module/layout on a flat surface without damaging the motors. If you use 1x4 pine, the 3 1/2" width will just clear the machines, and if you don’t use the machines, 1x3 will work just fine as long as there are no long runs between the leg supports. Hope this information helps!
As a cabinet maker, I believe MDF is a valuable product, however I would not recommend its use for structural components. I agree with the previous post concerning Birch plywood. There would be little concern about warpage or shrinkage. Screws and other fasteners would hold better as well. In addition MDF would be heavier. Good Luck!
“MDF” and “lightweight” are not generally found in the same sentence… [;)]. I would also second the caution about its strength in butt joints.
You are probably better off building with 1x4 (actually 1x3 1/2) or 1x5 (4 1/2) framing, or ripping good quality ply to those dimensions. Eliminate the plywood tabletop, substitute 2" extruded (not expanded) foam. Over a grid spaced at 24"x24", it should be plenty strong.
Not sure if I was clear on my original post. The type of MDF that I was planning on using was the type that they make door and window moulding out of. I held all 8 of them that I would need in my hand and they did not feel all that heavy to me. Our local Home Depot has 1x3’s and 1x4’s of this stuff and when laid horizontal seem pretty strong for a small n scale layout. I can see the argument about the butt joints not being very strong and had planned to have these re-inforced with pieces of 2x2, same material as the legs.
Thanks once again and I look forward to your responses,
The biggest advantage to my way of thinking is MDF has a paper surface that is absolutely smooth solving a number of preparation problems for plywood before laying track. I have seen layouts done cookie cutter style form 4 x 8 sheets that look pretty good. Since not much history exists I would want to be sure and not scrimp on the support side for fear of having some sagging happen over time.
I would be very concerned about the possibility of sagging if this stuff is laid horizontally. Like particleboard it really isn’t very strong. Check out the Weyerhaeuser poplar lumber that you might also find in your HD. This wood is smooth, strong and stable and relatively inexpensive. It is easy to machine and has no knots. It also takes screws and glue well.
" Like particleboard it really isn’t very strong. " In my experience there is nothing like or as bad a particle board unless you consider vinyl upholestery, polyester leisure suits and double knit fabrics, Yugos, Chia pets and maybe a few more.