What should determine the joist lumber size between 1x3 and 1x4. Seems to me 1x4 is a little overkill, but I seem to see about an equal division in references I read. Just starting bench work, and appreciate the help.
Hal
What determined the size for me was the lumber yard sold 1x4’s and not 1x3’s.
Dave H.
The larger the size of the joist the greater the span between legs.I have 4x1 joists on my layout and a 8ft spacing between legs. I can walk on the layout with no apparent deflection or sag.
Availability of lumber is the primary determining factor. 1 x 4 seems to be readily available and is thus the size of choice even though the inherent strength of the L girder is over kill for the weight of our layouts. Lynn Westcott needs an attaboy for its introduction to our hobby .
Will
I am not sure what a L- girder is ?[:(]
L-girder is a type of open benchwork construction that gives a bit more flexibility than the traditional open grid work type. Basically, it consists of a 1x3 or 1x4 mounted vertically, with a 1x2 secured to one narrow side of the 1x4 horizontally, making an L-shape. Two L-girders are usually spaced anywhere from 2 - 4’ apart, and have legs somewhere near each end (6 - 8’ apart, as mentioned above), making a very stable and strong base for the rest of the benchwork. The spacing depends, of course, on how big you want that base to be.
Once the L-girder frame is in place, you use 1x2s mounted on the narrow edge perpendicular to the L-girders as the support for the risers that actually hold the sub-roadbed, scenery base, etc. Again, spacing of the supports depends on the type of sub-roadbed you’re using, but 18" - 2’ apart is common.
Kalmbach has a great book called something like “Model Railroad Benchwork Made Easy” (can’t find my copy right now, so I’m not sure of the exact title [:)]) that goes into great detail on the various types of benchwork systems, and gives step-by-step instructions on building them. Worth the money!
[banghead] I guess that I don’t get it[:(], It seems to me that your spending more time and money to make the l girder than a 2x4 would cost. what would the advantage be ? lighter weight? May be it would be helpful if I could see a picture of one some where.
ennout
Try looking at the illustrations here: http://rail.felgall.com/lg.htm
And here : http://kahnawake.pass.free.fr/support_l_girder_angl.html
And here: http://members.fortunecity.com/gknowles1/layout/dl/dl.htm
Hope this helps
Andre
The construction of the “L” girder is correct but I would recommend the method from the Book Basic Benchwork, (Title is close) to GLue and Screw the 1x2 to the top of the 1 x4. Also, the 1x2 as the joist is to light, you can not screw to it when putting in a riser with that said using a 1x3 as the joist will give you enough wood to screw to fro your riser. If you are unaware these are NOMINAL sizes for wood actual for a 1x2 is 1/2 x 1 1/2, so you can see that as a joist the 1 1/2 is leg you couls onlt get in 1 screw for a riser which makes a pivot point. not good unless you want it to fold down.
This is my $.02, I am using this method for a 22ft by 18 ft layout now.
The weight is less for an L-girder, but that’s not the main advantage. The big one is the flexibility of construction and ease of modification. If the framework were built of 2x4’s in place of the L-girder, you’d have the difficulty of attaching either the cross pieces or the track risers. The cross piece is screwed to the L-girder up through the top plate, into the bottom of the cross piece. If a cross piece needs to be moved (ie. switch machine location, scenery elements, etc), it’s a simple matter of pulling out the screws and moving it. One point that may not have been clear, glue the parts of the L-girder together, but NOT the cross members or risers. These should only be screwed into place for the reasons stated above. Wallboard and deck screws, and cordless drills with some torque are newer than the L-girder idea, so these have made it much easier to build.
I’m using 1x2 joists and 1x2 risers, and have no problems getting two 1 1/4" drywall screws through the riser to the joist. I just use a countersink drill to place the screw holes on a slight diagonal, and they hold fine – the risers are solid.
Really thanks for the fast replies to my question. I just checked at my home store and sure enough, the inventory of 1x3 is not great & the quality is poor to worse, but 1x4 are plentiful with good chance to get some straight ones. I’m going with the 1x4s for my joists.
Hal
In Linn Westcott’s excellent book " How to Build Model Railroad Benchwork", there’s a table telling you how long a span each size of L-girder (1x3, 1x4, 1x6, etc.) will work without excessive flexing or deflection. An excellent book, everybody should have a copy of the updated edition.
Jim
I find 1x3’s usually are precurved for your next boat project. 1x4’s are usually straighter, though you sometimes have to search throught the whole bin to find the straight ones.
If you have access to a band saw, table saw or radial arm saw you can cut 1x6’s down to 1x3’s. That may or may not save you money over buying 1x4’s.
Enjoy
Paul
The other benefit of the L-Girder method is that cheap 2x3 and 2x4 tend to warp as they dry out (and kiln-dried lumber is expensive) while the built up L-girder, if glued should not warp.
For size, I think 1x4’s would do the job. I made a portable layout, using 1x4’s for the frame, and I found that they were very heavy, and I think 1x3’s would have been better. So, I’d say 1x4 for your L-Girder would be a good, sturdy size.
How 'bout making the L girders out of plywood? Sure beats the heck out of searching through the lumber bins, although 3/4 inch ply can be quite heavy!!
Neat, I will try taht in the log area, it is not framed yet.
See live and learn.
I used 1x4 ash [hardwood similar to oak] for my L-girders. Ripped them into two 1x2 strips for 2 3/4 x 2 L-girders. Hardwood is more expensive, but it is straight, dry, and strong. And it doesn’t take a truckload to build a layout. Then I used construction grade lumber for the crossbars, legs, and braces.
I used 2x4s and used a pocket hole drill on the crossmembers so I could fasten the crossmembers from the top. It was faster and easier. Scewing up through the L girder into the crossmembers is hard. The strengnth issue is no longer there is you use foam instead of 100lbs of plaster.