I just finished building a table using the L girder system. I am ready to attach the plywood top to the L girders. The instuctions were not in the MRR magazine that I have. I would love any help that anyone can give me. Thanks
The only thing I do is screw the plywood to the girders. It is less traumatic on them than nailing. (unless you happen to have an air nailer).
I use drywall screws for 1/2" ply and use an inexpensive cordless drill to drive them in. If any changes are made in the future, the screws come right out.
Bruce in the Peg
I agree with Bruce…using screws is better than nails. I would think that screwing the plywood from below would work well. I imagine that you are using 1 x 2s for the leg of the “L” . Applying the screws through the 1 x 2 into the plywood from below would allow you to make changes easier in the future if that’s what you wanted to do. I built a layout where I screwed the plywood down from the top, then of course covered the screws with roadbed and track. A few years later I had to take it apart, but I wanted to salvage some of what I had made. Unfortunately, I needed to remove the track, then roadbed, then plywood. The other way, just cut the rails and roadbed where you want to dismantle or make a change, and unscrew the plywood section from below. Now you still salvaged completed sections of your layout.
Mike
I pre-drill pilot holes to preclude any splitting on the L-girders. Then I glue with carpenter’s glue, and finally cinch it all up with a some wood or drywall screws into the pilot holes. The screws are cheap insurance (the glue should hold well), but what really counts is their ability to keep the glued surfaces together properly until the glue sets.
This may just be a matter of semantics here, but the plywood is attached on top of the joists; the joists are what are attached to the L-girders(i.e. on top of them), usually recc. at 16 inch intervals.
Jim
Boy, do I feel stupid!!! Here, for the past twenty-eight plus years I have attached joists to the L-Girders, attached risers with a cleat to the joist and then laid the subroadbed - I have never used a plywood table top but, instead, have used subroadbed cut from 1/2 inch plywood - atop the cleat. All screws are, therefore, below the “tabletop” facilitating changes when I wish/need to do so.
Not only have I been proven to know nothing about building switches nor about electricity but I must now face the fact that I know nothing about carpentry and benchwork.
Boy, my next layout should be perfect.
You mean, Kinda like this?
Me too! Actually I use plywood sub roadbed quite a bit, but yes! The joists go on top of the l-girders, and then whatever the subroadbed is on that.
I use screws for all my benchwork, every phase. I also do as Selector has mentioned, I predrill…it takes just a minute more, but is much safer so as to eliminate the possibility of splitting wood. Screws are so much stronger and faster to install, while nail hammering is traumatic on the structure. Also, if you make a mistake or need to change / modify your benchwork,… ever try to take things apart or pry nails without ruining something? With screws, just back them out with your handy dandy cordless screwdriver.
To paraphrase the late Linn Westcott, who originated the L girder system;
“Drive all attachment screws up from underneath - joists to L-girders, risers to joists and subgrade to risers. That way, when disassembly becomes necessary, they can be removed, and the structure modified, without disturbing the finished, landscaped top surface.”
Equally important, if screw removal is necessary the screws can be located without using a metal detector!
My layout is ‘C, acts like L, girder,’ framed with steel stud material. I have actually left most of the joists loose until their best location can be established (by the best riser location for subgrade support.) IMHO, even a graduate civil engineer would be hard put to design the entire roadbed support system on screen or paper and get every detail absolutely right, especially since track alignment can and does change between concept and operation.
Chuck (modeling Central Japan in September, 1964 - on L-girder framing)
RT
You are not alone. Even when I have used a plywood table top instead of plywood subroadbed, I used a cleat to screw into the joist or riser and plywood from below. I’m learning to not post so much on forums so that I quit revealing my ignorance.
Fred W
[(-D][(-D][:D] Could not have said it any better. [tup]
Another vote for: “Been there, done that!” [#wstupid][:D]
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