How about MDF under Homasote instead of 3/4 CDX Ply? - Model Railroader Magazine

I have used MDF for other projects, including furniture and speakers.

I would not use it for a cookie cutter model railroad layout. It needs pilot holes for all screws. It does not take to bending well, which is a requirement of cookie cutter construction mentioned in the original post.

I would use it for a table top layout with foam above, specifically 1/4" MDF with 2" or more of extruded polystyrene laminated above the MDF. This is a very stable, solid and quiet table top.

For cookie cutter, 3/4" AC plywood is hard to beat. A big part of the reason is the verticle curves comeout just right with it. With 1/2", you have to excercise care because you can easily get too sharp a transistion.

I believe that Tom is referring to what is called OSB (Oriented Strand Board) around MN and OK. In OK, OSB was by far the cheaped 4x8 sheets that Home Depot and Lowes had.

Splines of 1/4" MDF would work well (1/4" thick MDF ripped 3/4" to 1" wide, on edge) - Masonite®, Homasote®, pine, etc also work well for splines.

Nigel N&W in HO scale, 1950 - 1955 (..and some a bit newer too) Now in San Jose, California