having built, l GIRDER T GIRDER AND PLAIN OLD FRAME IT TO h3## sections, I offer the following observations.
L girder is a huge plus for screwing into, or rather from, it has a larger accessible flange.
in lynn westcott's day screws were flat blade. counter sink, drill and twist that screw driver... with the Phillip's head and myriad other drive choices in screws today and the large range of very stable glues... this is all much easier than ever before.
secure you top to the bottom with finishing screws if you are using plywood use fine tooth screws for dimensional lumber pre-drill and use course screws. glue both assemblies if using plywood or dimensional material
if you use plywood for your cross braces you can shape the contour of the cross braces as you go, hence removing the need for risers.
it is best to use square drive or regular head screws for mounting your uprights and cross members, that way they are easily discerned if you have to re-located material
the need to cross brace your legs with long runs of strip is not essential but use at least a 6"X 6" diagonal plywood brace in all corners
I like to 'box" my l girder with a solid section the same height as the "riser" of the L girder.
before you start doing a lot of
wet work" cut and install a fascia board contoured to match your terrain, you can trim it down to contour after you finish roughing out your scenery but it will provide stability, if you use masonits for this you can also get gentle curves along the front of the layout.
I always lean towards ripping furniture grade ply for my structural members, dimensional lumber varies so much these days that it is a crap shoot of you try and match up what you already have.
